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  Subjects -> AGRICULTURE (Total: 661 journals)
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Journal Cover Livestock Science
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   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1871-1413
     Published by Elsevier Homepage  [2563 journals]   [SJR: 0.728]   [H-I: 63]
  • Efficacy of dimethylglycine as a feed additive to improve broiler
           production
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): I.D. Kalmar , M.W.A. Verstegen , D. Vanrompay , K. Maenner , J. Zentek , C. Iben , R. Leitgeb , A. Schiavone , L. Prola , G.P.J. Janssens
      Dimethylglycine (DMG) is a naturally occurring glycine derivative, which is useful as additive to broiler diets as it improves nutrient digestibility and reduces the development of broiler ascites syndrome. This study evaluated the efficacy of dietary DMG to enhance performance of broiler chickens. Three trials were conducted to evaluate the effect of dietary supplementation with 1g Na DMG/kg on growth performance and carcass characteristics. In Trial 1, the effect of sex was also assessed in a 2×2 factorial arrangement of treatments. In Trials 1 (Germany), 2 (Austria), and 3 (Italy), each treatment consisted of 6, 12, and 11 replicate pens with 20, 15, and 16 one-day-old broiler chickens per pen, respectively. Dietary DMG supplementation resulted in improved feed conversion ratio (FCR) in the starter phase by 8.8% (P=0.004), 6.4% (P=0.001), and 4.8% (P=0.006) compared with the control diet in Trials 1, 2, and 3, respectively. The overall FCR improved in broiler chickens fed the diets supplemented with DMG by 3.8% and 4.1% in Trials 1 (P=0.007) and 3 (P=0.006), respectively. In addition, final body weight increased by 5.5% (P=0.001) in Trial 2 and production value improved by 6.8% (P=0.015) in Trial 1 by dietary DMG supplementation. Mortality in all trials was similar between dietary treatments. In all 3 trials, cold carcass weight and total meat yield were as well similar between broiler chickens fed the control and DMG diets. In Trial 1, dietary DMG had no effect on breast meat yield in male broiler chickens, but it increased breast meat yield in female broiler chickens (diet×sex, P=0.004). Organoleptic quality of roasted breast meat assessed only in Trial 2 was not affected by dietary treatments. In conclusion, dietary supplementation of DMG at 1g Na DMG/kg can considerably improve s production performance in broiler chickens.


      PubDate: 2014-04-27T22:53:02Z
       
  • The SNPs in the promoter regions of the bovine FADS2 and FABP4 genes are
           associated with beef quality traits
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Hirokazu Matsumoto , Takuya Nogi , Ichiro Tabuchi , Kenji Oyama , Hideyuki Mannen , Shinji Sasazaki
      Genetic factors are known to influence meat quality in beef cattle. Expression of fatty acid desaturase 2 (FADS2) and fatty acid-binding protein 4 (FABP4) genes in the fat metabolism pathway has been reported to influence fat-related traits. In this study, we aimed to discover DNA polymorphisms in the promoter regions of the FADS2 and FABP4 genes in cattle populations to develop genetic markers. As a consequence, one single nucleotide polymorphism (SNP) in the FADS2 promoter (FADS2 g.-823G>A) and two linked SNPs in the FABP4 promoter (FABP4 g.-295A>G and FABP4 g.-287A>G) were identified. All of them were assumed to influence binding sites for transcription factors, suggesting these SNPs influence the genes׳ expression and beef quality. Therefore, we performed association analysis between the genotypes and traits. Our results revealed that the FADS2 g.-823G>A had significant effects on several traits including beef marbling score (BMS). BMS of the G/G animals in a Holstein population (2.36) was higher than that of the G/A animals (2.13). The same tendency was observed in Japanese Black populations. On the other hand, although the FABP4 SNPs also had significant effects on some traits, they did not show additive effects on any of the traits analyzed in this study. Our results suggest that the FADS2 g.-823G>A is a useful genetic marker for breeding in beef cattle.


      PubDate: 2014-04-27T22:53:02Z
       
  • Lamb performance, milk production and composition from ewes supplemented
           with soybean oil partially replaced by fish oil blend
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Evandro Maia Ferreira , Alexandre Vaz Pires , Ivanete Susin , Renato Shinkai Gentil , Susana Gilaverte , Michelle de Oliveira Maia Parente , Marcos Vinicius Biehl , Claudio Vaz Di Mambro Ribeiro
      The objectives of these experiment were to evaluate the effects of small amounts of fish oil blend supply in partial replacement of soybean oil on dry matter intake (DMI), lactation performance and milk fatty acid composition of ewes and also on performance of their lambs. Fifty Santa Inês lactating ewes (63±6kg of initial BW; mean±SD) were penned individually and used in a randomized complete block design with 10 blocks and 5 treatments. The oils were added to a basal diet that contained 700g/kg DM of concentrate and 300g/kg DM of forage (fresh sugarcane bagasse). The treatments were as follows: (1) basal diet without added oil (CONT); (2) 40g/kg DM of soybean oil (0FO); (3) 2.5g/kg DM of fish oil blend+37.5g/kg DM of soybean oil (25FO); (4) 5g/kg DM of fish oil blend+35g/kg DM of soybean oil (50FO); and (5) 7.5g/kg DM of fish oil blend+32.5g/kg DM of soybean oil (75FO). All diets were isonitrogen (140±4g/kg DM of CP). Once a week, from the second to the eighth week of lactation (weaning time), ewes were separated from their lambs, stimulated by a 6-IU intravenous oxytocin injection, and milked to empty the udder. After 3h, milk production was obtained after the same procedure. DMI (kg/d; % of BW and g/kg BW0.75) was higher for ewes fed the control diets vs. fat-supplemented. However, no effect was observed on DMI when fish oil blend inclusion in the diets increased. Nevertheless, milk production increased linearly when fish oil blend replaced soybean oil. As a consequence, the preweaning average daily gain (ADG) of lambs increased linearly. Milk fat concentration was similar for all diets. Milk protein and total solids concentrations decreased linearly when fish oil blend addition increased. Lactose milk concentration was higher for ewes fed the fat-supplemented diets vs. the control. Stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid and CLA cis-9, trans-11 showed higher concentrations in milk of animals fed diets containing soybean oil and fish oil blend compared to the control diet. Vaccenic acid, CLA trans-10, cis-12, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased linearly with fish oil blend inclusion. Small amounts of fish oil supplementation does not exert an additional effect on the concentration of CLA C18:2 cis-9, trans-11 as compered to exclusive use of soybean oil. However, the addition of 7.5g/kg DM of fish oil blend mixed with 32.5g/kg DM of soybean oil is recommended, because it increased the concentration of EPA, DHA and C18:1 trans-11 in the milk, as well increasing the performance of the ewes and their lambs.


      PubDate: 2014-04-27T22:53:02Z
       
  • Slaughter weight, sex and age effects on beef shear force and tenderness
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): J. Lucero-Borja , L.B. Pouzo , M.S. de la Torre , L. Langman , F. Carduza , P.M. Corva , F.J. Santini , E. Pavan
      In Argentina, beef cattle prices decrease as slaughter weight increases regardless of animal age or carcass maturity, and this decrease is significantly greater in heifers (15%) than in steers (5%). The objectives of the present study were to (1) determine whether shear force and tenderness differ between heifers of different slaughter weight, and between heifers, steers and cull cows of similar slaughter weight; (2) evaluate whether such differences, if any, could be overcome by extending beef aging period; and (3) understand the main causes of such differences in beef shear force and tenderness. Meat from heavy heifers (H-HEIFER, 381–420kg BW) was compared to meat from light heifers (L-HEIFER, 300–340kg BW), steers (STEER, 391–450kg BW) or cull cows of similar weight (COW). At slaughter, carcass characteristics were determined and Longissimus thoracis (LM) and Gluteus medius (GM) muscle samples collected for shear force determination. Total and insoluble collagen, sarcomere length and intact troponin-T content, and sensory panel scores, were evaluated for LM. Aging effect was evaluated for shear force and sensory panel scores. Irrespective of muscle or aging period, increasing heifer slaughter weight did not impact negatively on beef shear force or tenderness levels; heifers and steers of similar slaughter weight had similar beef shear force and tenderness levels; whereas heifer beef was more tender (P<0.05) than that from cow of similar slaughter weight. Tenderness differences were not overcome by extending the aging period. Based on a principal component analysis, shear force and tenderness differences appear to be associated to the variation in chilling rate and sarcomere length.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effect of estrus expression prior to ovulation synchronization protocols
           on reproductive efficiency of lactating dairy cow
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Mufeed A. Alnimer , Mohammed M. Ababneh
      Cosynch-72 (CO-72) is one of the most widely known timed AI (TAI) protocols in cattle. The protocol involves giving GnRH on d-7, PGF2α on day 0, and the second GnRH on day 3 concurrent with AI. CO-72 has been adapted as the standard reproductive management protocol in postpartum (pp) dairy cows in several large dairy farms in Jordan. This research was conducted to study the effect of estrus detection and presynchronization strategy prior to Cosynch protocol on reproductive efficiency of lactating dairy cows in Jordan. Cows (n=1220) were injected with PGF2α on day 30±3 pp and observed for signs of estrus over the experiment. Cows detected in estrus before (n=21) or after (n=409) PGF2α injection underwent to CO-72 protocol starting with GnRH 12 days after heat (control group; HCO-72). In contrast, cows that were not detected in estrus were randomly assigned into two treatments (NHCO-72; NHOV-CO-72): cows in the NHCO-72 treatment underwent a CO-72 protocol on day 44±3 pp; while cows in the NHOV-CO-72 treatment underwent a first CO-72 protocol without AI starting on day 44±3 followed by another CO-72 protocol with AI seven days after the last GnRH injection (day 61±3). Cows showed premature estrus (≤48h post-PGF2α) (n=184) were excluded from the study. Cows in NHOV-CO-72 treatment had higher (P<0.05) pregnancies per AI (P/AI) and reduced pregnancy losses (PL) (42.8, 14.5%) than those in HCO-72 (27.1, 43.0%) and NHCO-72 (26.8, 42.5%) treatments, respectively. Pregnancies per AI and PL were significantly (P<0.05) affected by parity and season. Primiparous had higher P/AI and reduced PL (35.4, 21.4%) than multiparous cows (28.7, 41.7%; respectively). Cows inseminated in cold months had higher P/AI and reduced PL (35.9, 17.9%) than cows inseminated in hot months (24.8, 52.9%; respectively). In conclusion, presynchronization in the NHOV-CO-72 treatment increased P/AI and reduced PL when compared to the other two treatments. Detection of estrus before the beginning of Cosynch did not affect fertility and cows exhibiting heat at any time during the synchronization protocol should be inseminated to maximize P/AI. Improvement in the NHOV-CO-72 in this study was probably due to later insemination and not for induction of cyclicity as there were no differences between HCO-72 and NHCO-72.


      PubDate: 2014-04-27T22:53:02Z
       
  • Nitrogen balance, blood metabolites and milk fatty acid composition of
           dairy cows fed pomegranate-peel extract
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): M.J. Abarghuei , Y. Rouzbehan , A.Z.M Salem , M.J. Zamiri
      An experiment was carried out to determine the effect of pomegranate peel extract (PPE) on nitrogen balance, blood parameters and the milk fatty acid profile of dairy cows. Four Holstein cows were used in a 4×4 Latin square design with 28-d periods and 4 treatments: PPE0 (no extract), PPE400 (400ml PPE/cow/d), PPE800 (800ml PPE/cow/d) and PPE1200 (1200ml PE/cow/d). Nitrogen balance, blood parameters and the milk fatty acid profile were measured. Determination of secondary metabolites showed its high content of aqueous fraction, total phenolics and total tannin with reasonable content of saponins. Outputs of N in milk were quadratically increased (P=0.044) by inclusion of PPE at 400 and 800ml PPE/cow/d in the diet. Blood cholesterol (quadratic effect, P=0.043), blood urea nitrogen (linear effect, P=0.047) and milk urea nitrogen (quadratic effect, P=0.0008) concentrations decreased with adding PPE. Supplementation with PPE quadratically lowered total saturated fatty acid (P=0.005), proportions of C12:0 (linear effect=0.040), C16:1c9 (quadratic effect, P=0.011), C18:0 (linear effect, P=0.083, quadratic effect, P=0.011) and ω6/ω3 (quadratic effect, P=0.007). Amount of C18:3c (n-3) (linear effect, P=0.046), DHA (C22:6) (quadratic effect, P=0.009) and EPA (C20:5) (quadratic effect, P=0.012) were increased by inclusion of PPE. Adding PPE lowered blood cholesterol, blood urea nitrogen and milk urea nitrogen. Milk from cows fed PE had significantly lower total saturated fatty acid, desirable ω6/ω3 ratio and higher content of EPA and DHA.


      PubDate: 2014-04-27T22:53:02Z
       
  • The effect of fat type and l-carnitine administration on growth, feed
           digestibility and blood metabolites of growing Afshari lambs
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): A.D. Foroozandeh , H.R. Amini , G.R. Ghalamkari , M. Shahzeydi , S.M. Nasrollahi
      This study was conducted to evaluate the effect of fat type and l-carnitine supplementation on feed intake, nutrient digestibility, growth, and blood metabolites in growing Afshari lambs. Twenty-four-male lambs with an initial body weight of 16±0.4kg were used in a completely randomized design with a 2×2 factorial arrangement of fat type with or without supplemental carnitine in an 84-day feeding period. The diets were isoenergetic and isonitrogenous. Soybean oil or a commercial Ca-protected fat were included at 4% of the DM of diet, each with or without 100mg l-carnitine top dressed per kg of diet. Initial weight was equalized across treatments. At the end of experiment, blood was sampled from each lamb and concentrations of serum glucose, BUN, total protein, triglyceride, total cholesterol, HDL, and LDL were determined. There was no interaction between fat type and carnitine administration on feed intake, nutrient digestibility and growth. Fat type did not affect feed intake, but lambs fed soybean oil had greater DM and EE digestibility (P<0.05), and tended to have higher CP digestibility. Supplemental l-carnitine did not affect feed intake, but improved EE digestibility (P<0.01) and tended to improve CP digestibility (P=0.10). Although fat type did not affect growth of lambs, l-carnitine administration tended (P=0.13) to improve body weight and ADG, thus improving FCR (P<0.05). Fat type interacted with l-carnitine administration for cholesterol and LDL concentration in blood; l-carnitine administration significantly decreased them only for the soybean oil diet (P<0.05). Lambs fed with soybean oil, compared with Ca-protected fat, had more (P<0.05) total protein and BUN and tended (P=0.11) to have lower triglyceride concentrations in the blood. Under conditions of the current study l-carnitine might improve growth, dietary fat digestibility, and blood metabolites of lambs fed diets with supplemented fat. Supplementing different fat types had a minimal effect on responses of lambs.


      PubDate: 2014-04-27T22:53:02Z
       
  • Investigation of sources of variation in the effect of prepartum protein
           supplementation on early lactation performance of dairy cows
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Tuomo Kokkonen
      The objective of this study was to evaluate the effects of prepartum protein supplementation on subsequent milk yield, milk composition, feed intake and tissue mobilisation by using regression analysis. The data were compiled from 15 peer-reviewed articles that included 47 treatments. Crude protein content of prepartum diets ranged from 97 to 206g/kg DM. For the evaluation of potential interaction between prepartum protein supplementation and basal diet, diets were categorised as grass silage-based, maize silage–soya bean meal (SBM) and other diets (alfalfa/grass hay/straw). A significant interaction (P<0.05) between dietary protein content and type of diet was found in milk protein yield and postpartum dry matter intake. This suggests that the impact of prepartum protein feeding on subsequent lactation performance may depend on the composition of basal diet. Milk protein yield and postpartum dry matter intake responses to prepartum SBM supplementation in maize silage-based diets were negative. Higher impact was observed when the proportion of hay or straw was high in the prepartum diet. In grass silage-based diets, the production responses were intermediate and more variable than in the other groups. No relationship was found between prepartum protein supplementation and postpartum tissue mobilisation. In conclusion, excessive prepartal SBM supplementation in maize silage-based diets may decrease milk protein yield and dry matter intake during early lactation. Positive responses to increased prepartal protein supply can be achieved in hay or straw based diets.


      PubDate: 2014-04-27T22:53:02Z
       
  • Repeated hormonal treatment and laparoscopic ovum pick-up followed by in
           vitro embryo production in goats raised in the tropics
    • Abstract: Publication date: Available online 19 April 2014
      Source:Livestock Science
      Author(s): Deisy J.D. Sanchez , Carlos H.S. Melo , Joanna M.G. Souza-Fabjan , Francisco C. Sousa , Amanda A. Rocha , Iana S. Campelo , Dárcio I.A. Teixeira , Alexsandra F. Pereira , Luciana M. Melo , Vicente J.F. Freitas
      The objectives of this study were to evaluate the ovarian response of oocyte donor goats which underwent seven repeated ovulation hormonal treatments and laparoscopic ovum pick-up (Experiment 1), and to compare the in vitro production (IVP) of embryos from goats hormonally treated for eighth times to IVP of embryos from females with a single hormonal treatment (Experiment 2). In Experiment 1, 12 goats were subjected to 7 repeated hormonal treatments and laparoscopic ovum pick-up (LOPU) every 2 to 3 weeks, and the following variables were recorded: number and size of punctured follicles, number of recovered cumulus-oocyte complexes (COCs), recovery rate and COCs quality. In Experiment 2, IVP of embryos from goats hormonally treated for eighth time (repeated-treated group, RT) was compared with IVP of embryos from 10 other goats with only one hormonal treatment (single-treated group, ST). In this step, in addition to variables observed in Experiment 1, cleavage, blastocyst rates at Days 7 and 8 of culture, hatched rate and the number of blastomeres per embryo were also evaluated. In Experiment 1, when comparing LOPU sessions, no difference (P>0.05) was verified for number of punctured follicles, number of recovered COCs and recovery rate. However the percentage of large follicles was different (P<0.05) between LOPU 1 (27.7±10.5) and 7 (12.4±12.1), the latter being similar to sessions 2 (13.9±10.9), 3 (13.4±7.9), 4 (13.2±10.7), 5 (22.4±14.7) and 6 (17.7±15.8). The percentage of COCs suitable for IVM was lower (P<0.05) for LOPU 1 (80.6%), 2 (82.4%) and 3 (79.7%) than LOPU 6 (91.3%) and 7 (95.2%). In Experiment 2, total number of follicles aspirated/goat and total number of COCs recovered were similar (P>0.05) for RT (18.0±5.8 and 12.3±3.7, respectively) and ST (19.4±7.8 and 15.8±7.7, respectively) groups. However, the recovery rate was lower (P<0.05) in the RT vs the ST group (68.5 and 81.4%). The percentage of small, medium and large follicles was similar (P>0.05), respectively, for RT (28, 55 and 17%) and ST (20, 65 and 15%) groups. The percentage of COCs suitable for IVM had no difference (P>0.05) for RT (96.6%) and ST (93.7%) groups. No significant difference was observed between RT and ST groups for: cleavage rate (68.6 vs 67.0%), blastocyst rate at Day 7 (27.9 vs 31.8%) and 8 (27.9 vs 34.1%), hatched rate (33.3 vs 53.3%), and blastomeres/embryo (252.9 vs 229.8). In conclusion, in goats raised in tropical climate, the IVP of embryos from oocytes obtained by LOPU could to be an efficient and suitable method for rapid propagation of genetically superior animals. Donor goats, even after repeated hormonal treatments followed by LOPU, maintained the ovarian response for oocyte and embryo production, becoming close to reality the term “oocyte permanent donors”.


      PubDate: 2014-04-27T22:53:02Z
       
  • Association and expression analysis of porcine ACLY gene related to growth
           and carcass quality traits in Italian Large White and Italian Duroc breeds
           
    • Abstract: Publication date: Available online 18 April 2014
      Source:Livestock Science
      Author(s): Roberta Davoli , Silvia Braglia , Martina Zappaterra , Carla Redeghieri , Marco Comella , Paolo Zambonelli
      Lipogenesis is a complex metabolic process that involves many enzymes: one of them, ATP citrate lyase (ACLY) is related in fatty acid biosynthesis. The aim of this study was to find association between two Single Nucleotide Polymorphisms for ACLY porcine gene and the most important productive traits and to verify the expression level of this gene in Italian Large White and Italian Duroc pigs in muscle and backfat tissues. The first SNP ACLYc.NM_001105302 2956T>C lies in a portion of the coding region corresponding to human exon 25 while the second SNP ACLY c.*523T>C is located in the porcine ACLY gene 3′ UTR. In Italian Large White pigs SNP ACLYc.NM_001105302 2956T>C shows an association with Average Daily Gain, and CC genotype is the most favourable to animal growth, whereas the same SNP in Italian Duroc pigs is not associated with analysed traits. This difference in association results may be a plausible evidence of the divergent genome background between Italian Large White and Italian Duroc breeds, as reported in recent studies. On the other hand c.*523T>C SNP shows concordant association results, as in both breeds CC animals display the best values for the analysed carcass traits. Moreover, we evaluated in both breeds ACLY gene expression level in skeletal muscle and backfat. Italian Duroc pigs, according to their elevated marbling, have the highest ACLY gene expression in muscle, while Italian Large White pigs present the highest transcription level in backfat tissue. Furthermore ACLY expression is not influenced by the two studied polymorphisms, suggesting that these mutations do not affect gene transcription but might be in linkage disequilibrium with the causal mutation. In conclusion ACLY might be considered as new biomarker for genetic improvement schemes aimed to modulate the fat content, in carcass and in muscle.


      PubDate: 2014-04-27T22:53:02Z
       
  • Cow attributes, herd management and environmental factors associated with
           the risk of calf death at or within 1h of birth and the risk of dystocia
           in cow–calf herds in Western Canada
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Cheryl L. Waldner
      The risks of stillbirth and dystocia were measured for 29,970 full term births from 203 privately owned cow–calf herds in the 2002 calving season using on-farm supervised data collection. Mixed models adjusting for clustering by herd were used to examine associations between animal, herd management, and environmental factors and the risks of calf death at or within 1h of calving, any assistance at calving, and severe dystocia. The mean risk of stillbirth was 2.7%, any assistance at calving was 8.9%, and severe dystocia was 3.7%. After accounting for other risk factors including assistance at calving, calves from cows with a precalving body condition score (BCS) of ≤3 (P=0.002) or 4 (P=0.007) out of 9 were more likely to be dead at or within 1h of birth than calves from cows with a BCS of 5. Bred replacement heifers (P=0.003) and cows >10 years old (P=0.01) were more likely to have a stillborn calf than mature cows. Other risk factors for stillbirth included whether the calf was a twin (P=0.0001), the cow having a retained placenta or uterine prolapse (P=0.0001), month of calving (P=0.05), low precipitation during the previous growing season (P=0.0008), and assistance during the previous calving season (P=0.046). Cows that gained body condition from pregnancy testing to calving were less likely to require any assistance at calving (P=0.01). Cows with a BCS ≤3, 6, or ≥7 were more likely to have severe dystocia than cows with a BCS of 5 before calving (P=0.04). Assistance at calving and severe dystocia were less likely with each subsequent calving from the first through the third calf. Other risk factors for any assistance at calving and severe dystocia included male gender, being born as a twin, and birth earlier in the calving season. This is one of very few published studies to examine individual cow, herd, and environmental risk factors for both stillbirth and calving difficulty in a large number of privately-owned beef herds.


      PubDate: 2014-04-27T22:53:02Z
       
  • Incorporation of sexed semen into reproductive management of
           cow–calf operations
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): R.F. Cooke , D.W. Bohnert , B.I. Cappellozza , R.S. Marques , T. DelCurto , C.J. Mueller
      The objective of this experiment was to compare reproductive performance and weaning outcomes of beef cows inseminated with sexed or conventional semen. Over 2 consecutive years, lactating Angus×Hereford cows were assigned to an estrus synchronization+artificial insemination (AI) protocol. At the time of AI, cows were ranked by parity and assigned to be inseminated with conventional non-sorted semen (CONV; n=454) or with semen sorted for male sperm (SEXED; n=439). Beginning 18 days after AI, cows from both treatments were grouped and exposed to mature bulls for 50 days (1:25 bull to cow ratio). Cow pregnancy status to AI was verified by detecting a fetus via transrectal ultrasonography 40 days after AI. Calf birth date, sex, and birth BW were recorded during the subsequent calving season. Cows that were diagnosed as pregnant during the transrectal ultrasonography exam and gave birth during the initial 2 weeks of the calving season were considered pregnant to AI. Pregnancy rates to AI and final pregnancy rates (AI+bull breeding) were reduced (P≤0.05) in SEXED compared with CONV cows. The proportion of male calves born to AI or AI+bull breeding was greater (P<0.01) in SEXED compared with CONV cows. No treatment effect was detected (P=0.34) for weaning rate, whereas SEXED cows had a greater (P<0.01) proportion of steers in the weaned calf crop compared with CONV cows. Steers and heifers from SEXED cows were younger (P<0.01), whereas only SEXED heifers were lighter (P=0.05) at weaning compared with cohorts from CONV cows. Across genders, calves from SEXED cows had reduced (P≤0.01) weaning age and BW compared with calves from CONV cows. Cows assigned to SEXED had greater (P=0.05) kg of steer weaned/cow exposed to breeding, but reduced kg of heifer weaned/cow exposed to breeding (P<0.01) compared with CONV cows. Across genders, SEXED cows tended (P=0.09) to have reduced kg of calf weaned/cow exposed to breeding compared with CONV cows. In summary, inseminating beef cows with sexed semen reduced pregnancy rates, but increased the proportion of steers weaned and kg of steers weaned/cow exposed to breeding. However, overall kg of calf weaned/cow exposed to breeding was not improved by the use of sexed semen, particularly because of its negative impacts on weaning age and BW of the heifer progeny.


      PubDate: 2014-04-27T22:53:02Z
       
  • Farrowing environment has an impact on sow metabolic status and piglet
           colostrum intake in early lactation
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): J. Yun , K.M. Swan , K. Vienola , Y.Y. Kim , C. Oliviero , O.A.T. Peltoniemi , A. Valros
      This study investigated the effects of providing nest-building opportunities prior to parturition on sow serum non-esterified fatty acid (NEFA) concentrations and on colostrum intake of neonatal piglets during the early lactation period. We kept a total of 33 sows in (1) CRATE (N=12): the farrowing crate closed (210×80cm), with provision of a bucketful of sawdust, (2) PEN (N=11): the farrowing crate opened, with provision of a bucketful of sawdust, (3) NEST (N=10): the farrowing crate opened, with provision of abundant nest-building materials. All sows included in the experiment were confined to the farrowing crates after the first piglet was delivered until seven days post-parturition. We collected sow blood samples for a NEFA assay via indwelling ear vein catheters on days −3, −2, −1, +1, +2, +4, and +7 from parturition. To determine piglet IgG, IgM, and IgA concentrations, we collected blood samples from two healthy female piglets [N (piglet): CRATE=6, PEN=8, NEST=8] from among the gilts in each treatment at 0h, 12h, 24h, 48h, and 7 d via the jugular vein with a disposable syringe. Piglet growth during early lactation was slower in CRATE than in PEN (P=0.04). Post-natal mortality, including piglet deaths resulting from crushing or other factors, indicated no differences between the three treatments (P>0.10). Compared with sows in limited nest-building environments, sows in NEST tended to have higher serum NEFA concentrations during the experimental periods (P=0.07). Sow serum NEFA concentrations positively correlated with plasma oxytocin concentrations (r s =0.28, P<0.001) and piglet weight gain (r=0.16, P<0.05), and negatively correlated with the post-natal mortality ratio (r=−0.17, P<0.05) for seven days after birth. During early lactation, piglet serum IgG and IgM concentrations in NEST tended to be greater than the other treatments (P=0.05, P=0.07, respectively). IgG, IgM, and IgA concentrations in the piglets were greater in the first 48h than 7 d after birth (P<0.001, for all). In conclusion, farrowing crates did not reduce piglet post-natal mortality, but provision of nest-building materials to prepartum sows improved sow metabolic status, and successful colostrum intake measured via neonatal piglet serum IgG and IgM concentrations during early lactation. This may have potential to increase piglet survival and growth performance during lactation.


      PubDate: 2014-04-27T22:53:02Z
       
  • Attitudes of Canadian citizens toward farm animal welfare: A qualitative
           study
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Jeffrey M. Spooner , Catherine A. Schuppli , David Fraser
      As part of a larger project to determine if there are animal-welfare-related values shared by some commercial food–animal producers and non-producers in Canada, open-ended, semi-structured interviews were conducted to elicit opinions about animal welfare among 24 urban and rural residents not involved in commercial animal production. All participants possessed a self-described interest in food animal well-being and were therefore assumed to represent the views of Canadian non-producers most apt to engage in efforts to shape the animal welfare policies of governments and businesses. Participants described animal welfare in moral or ethical terms, expressed virtually unanimous support for animals having access to “natural” living conditions, and (somewhat less often) linked animal welfare to positive affective states. Maintaining reasonable health and biological functioning was seen as important but was not to take precedence over the benefits of natural living. Participants favoured small family farms and unanimously objected to confinement housing. Participants did, however, offer qualified support for intensive practices and were unanimous in not assigning blame to producers, whom they regarded sympathetically. Predictably perhaps, given our sample, most were critical of industries preoccupied with profits and of consumers who unthinkingly seek cheap food. Recommended ways of improving welfare included instilling in consumers a greater appreciation for the intrinsic value of humanely reared animals, and better education of children regarding the connection between animals and food. Disagreements arose over the welfare implications of organic production and approaches to animal advocacy. Differing demographic backgrounds, experiential involvement with food animals and knowledge of food animal production practices may have influenced the nature or specificity of welfare concerns. Many participants admitted a lack of knowledge about contemporary production practices and some expressed an interest in obtaining additional knowledge. These findings contribute to a broader effort to identify shared values among different stakeholder groups as a basis for formulating widely acceptable, farm animal care and handling polices.


      PubDate: 2014-04-27T22:53:02Z
       
  • Validation of a luciferase bioassay to detect the progestative activity in
           gilts whose estrus was induced by an uterotonic herb (Ligusticum
           chuanxiong)
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): H.M.M. Ahmed , J.Y. Yeh , W.J. Lin , N.E. Forsberg , W.T.K. Cheng , B.R Ou
      Ligusticum chuanxiong (LC) is an uterotonic herb. Ethanol extract of LC has potent progestative activity. The progestative activity in rat serum was well documented after oral and subcutaneous administration of LC. The objective of this study was to investigate the possibility of LC for estrus synchronization of gilts in place of synthetic progesterone. Eighteen gilts were randomly assigned into three groups, control group fed normal feed, positive control group supplemented with 20mg of altrenogest (Regumate®) and treatment group supplemented with 100g of LC daily for 22 consecutive days in feed. Blood samples were collected from jugular vein of gilts on the 22nd day before altrenogest or LC feeding. Estrus was monitored every day in the morning and the evening by observing the vulva swelling and reddening as well as nose to nose fence line contact between the boar and sow. Estrus was confirmed by testing the standing reflex in the presence of boar. All gilts in LC-fed group and 5 gilts in altrenogest-fed group came in estrus within 2–6 days after withdrawal of feeding, but did not show estrus during the feeding period. Whereas, all gilts in control group came in estrus during the feeding period. Progesterone responsive reporter plasmid was constructed by incorporating the progesterone response elements and TATA box at the multiple cloning site of pGL3 basic vector. Gilts serum progestative activities were measured by using luciferase reporter gene bioassay. Serum analysis showed that progestative activities of altrenogest- and LC-supplemented groups had a similar pattern. It is concluded that LC is a potential feed additive to be used for estrus cycle synchronization in swine industry.


      PubDate: 2014-04-27T22:53:02Z
       
  • History, structure, and genetic diversity of Brazilian Gir cattle
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): M.L. Santana Jr. , R.J. Pereira , A.B. Bignardi , L. El Faro , H. Tonhati , L.G. Albuquerque
      The Gir cattle breed (Bos indicus) is an important genetic resource for milk production throughout the tropics. The small number of Gir animals introduced in Brazil, rapid dissemination of this breed recently, and the intensification of selection practices could contribute to increase of inbreeding level and reduce genetic diversity in this population. The population was analyzed in terms of pedigree completeness level, inbreeding coefficient, coancestry, generation interval, effective population size, effective number of founders and ancestors, among others. Despite the low mean inbreeding (around 2%), minor problems were identified in the population structure of the Brazilian Gir cattle, e.g., trend of narrower bottlenecks in the pedigree in recent years. The effective population sizes based on inbreeding (94) or coancestry (165.9) as well as the effective number of ancestors (76) and founders (143) were relativity high. The major subdivision of the Gir breed was observed between 1993 and 2002 (dairy and dual-purpose herds, wide use of within-herd matings). In this period the level of inbreeding remained at a higher level, there was a small increase in coancestry and the number of equivalent subpopulations was approximately 6. After 2002, there was genetic exchange between subpopulations, reduction in the average inbreeding, pronounced increase in the average coancestry, and the number of equivalent subpopulations was about 2. Furthermore, it was found that the mean generation interval of the population tended to increase in recent years (around 9 years). About 2.3% of genetic diversity has been lost since the first generation of founders. Based on the effective population size, number of equivalent subpopulations, inbreeding, coancestry, and loss of genetic diversity, the Gir population is still highly structured, but there is ample room for artificial selection. The results regarding the effective number of founders and ancestors in the present population demonstrate the existence of bottlenecks in the pedigree and indicate the need for population structure monitoring. Nevertheless, the Brazilian Gir breed can perfectly face a breeding program with high selection intensity.


      PubDate: 2014-04-27T22:53:02Z
       
  • Estimation of methane emission using the CO2 method from dairy cows fed
           concentrate with different carbohydrate compositions in automatic milking
           system
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): M.N. Haque , C. Cornou , J. Madsen
      Two concentrates (MELK and VEM) with two different carbohydrate compositions were supplemented during milking in an Automatic Milking System (AMS). The objectives of this study were to estimate the effect of the concentrates on CH4 emission from dairy cows and to investigate the precision of the CO2-method when measuring in an AMS for different length of time. Holstein cows (n=36) were used with mean body weight of 660kg (SD=75.13) and average milk production of 31.7kg (SD=8.98), mixed parity and mixed lactation. Cows were allocated in two groups (n=18). After an adaptation period (period 1), each group received either 100% MELK (More Energy Lactating Cows; a newly introduced feeding system) or 100% VEM (Feed Value System for milk production) during periods 2 and 3. Besides, both groups were fed the same Total Mixed Ration (TMR) ad libitum in the stable. Air samples in the AMS from a point near the cows head were analysed every 20s using the Gasmet equipment based on Fourier Transform Infrared (FTIR) Spectroscopy Technique. The equipment ran continuously for 15 days over the three measurement periods (5 days×3 periods) with a 14 days waiting time in between the periods. Individual records of the CH4 and CO2 concentrations in the cows breath was calculated after subtracting the CH4 and CO2 concentrations in the stable air from the measured concentrations. The CH4:CO2 ratio was then multiplied with the calculated total CO2 production by the individual cows to get the quantitative CH4 production. Milk production and total dry matter intake (DMI, kg/day) were very similar in the two groups. The supplemented concentrate was allocated according to the individual milk yield and the intake ranged from 1.60 to 7.30kg/day in MELK cows and from 2.06 to 7.20kg/day in VEM cows. No significant difference was found for CH4 production in MELK and VEM groups over the three periods. A linear positive relation between the CH4 (g/day) and energy corrected milk (ECM, kg/day) production and the feed intake (DMI, kg/day) was observed for the entire period. The calculated CO2 and CH4 production were very similar in the two groups throughout the entire measurement period. The analysis of the precision of the CO2-method, using a 95% significance level, indicated that showing a difference of 9 or 5% in methane production requires a measuring period of 5 or 15 days, respectively, when using 18 cows per group. The study shows no effect of a limited change in supplementation of starch and sugar on CH4 production through feeding concentrates MELK or VEM in the AMS. To obtain an effect of changing the carbohydrate composition of the diet on the CH4 production, it is likely that a larger change in the diet is necessary. This can only efficiently be done by changing the TMR part of the diet.


      PubDate: 2014-04-27T22:53:02Z
       
  • Feed enzymes, probiotic, or chitosan can improve the nutritional efficacy
           of broiler chicken diets containing a high level of distillers dried
           grains with solubles
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): S. Swiatkiewicz , A. Arczewska-Wlosek , D. Jozefiak
      The aim of the experiment was to evaluate the effect of selected feed additives on performance, nutrient digestibility, meat quality, and bone characteristics of broiler chickens fed diets containing a high level of corn dried distillers grains with solubles (DDGS). A total of 480 one-day-old Ross 308 male chicks were randomly allocated to 1 of 8 treatments, each comprising 6 replicate cages with 10 birds per cage. In a 6-wk experiment, chickens were fed isocaloric and isonitrogenous experimental diets containing 0 (control) or 120g (starter phase) or 180g (finisher phase) DDGS/kg. The diet containing DDGS was not supplemented or supplemented with feed enzymes [200mg of enzyme with endo-1,4-β-xylanase activity (1000 fungal xylanase units/g)/kg, 200mg of enzyme with phytase activity (10,000 phytase units/g)/kg], 700mg sodium butyrate/kg, 108 cfu probiotic bacteria (Lactobacillus salivarius)/kg, 250mg of each herb extract (Taraxaci siccum, Urticae siccum, and Salviae siccum)/kg, 5g inulin/kg, or 3mL chitosan/kg. The incorporation of DDGS into the diet had no effect on growth performance at 21 and 42d of age and breast meat proximate composition, but negatively affected (P<0.05) apparent digestibility of dry matter and organic matter, metabolizable energy content of the diet, and retention of N and Ca. Inclusion of DDGS increased (P<0.05) the percentage of linoleic acid and total polyunsaturated fatty acids (PUFA), and decreased (P<0.05) the content of palmitic and stearic acid, as well as total monosaturated (MUFA) and saturated fatty acids (SFA) in breast lipids. At 42d, incorporation of DDGS into the diet decreased (P<0.05) bone breaking strength of femurs, without any effect on tibia indices. Some of the additives, i.e., feed enzymes, probiotic, or chitosan, improved (P<0.05) growth performance during either the first, second, or for the entire feeding period, nutrient digestibility, and retention of N and Ca. Feed enzymes also increased (P<0.05) bone breaking strength, yielding load, and stiffness of femurs. The results of this study indicate that DDGS can be included at a level of 120 (starter) or 180g (finisher)/kg in the diet of broiler chickens without any detrimental effect on performance, and feed additives such as enzymes (xylanase+phytase), probiotic, and chitosan can increase the nutritional efficacy of the diets with a high level of DDGS.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effect of dietary tryptophan to lysine ratio on growth of young pigs fed
           wheat–barley or corn based diets
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): M. Naatjes , J.K. Htoo , K. Walter , K.H. Tölle , A. Susenbeth
      There is considerable variation in recommendations for optimum tryptophan (Trp):lysine (Lys) ratio in diets of starter pigs up to 35kg body weight (BW) which may partly be due to differences in the composition of experimental diets, the experimental approach, and the mathematical model used for data analysis. The objective of this study was therefore to determine the Trp:Lys ratio required for maximum response of pigs (15–35kg BW; BW) offered a wheat–barley–soybean meal (WB) or a corn–soybean meal (C) based diet. Three mathematical models were applied to test to which extent the choice of model will affect the estimate of optimum Trp:Lys ratio. A 4-week dose–response growth study was conducted with 880 crossbred castrated male and female pigs. The pigs were randomly allotted to eight dietary treatments per diet type. A Trp-deficient diet (T1) was formulated for each diet type that met animals׳ requirements for all amino acids other than Trp (1.4g standardized ileal digestible (SID) Trp/kg diet) and Lys (10.5g SID Lys/kg diet). L-Trp was added to T1 diets to create six additional diets per diet type (T2–T7) with SID Trp concentrations increasing from 13.1% to 19.7% in WB based and from 14.3% to 20.9% in C based diets. To test whether Lys was the second-limiting amino acid, a Lys adequate diet was formulated (T8) for each diet type by adding crystalline Lys to the respective T7 diet. Pigs had free access to feed and water. Individual BW was recorded every two weeks and pen feed intake daily. For both diet types BW gain increased (P<0.01) and feed to gain ratio improved (P<0.05) with increasing Trp:Lys ratio. In the Trp-deficient diets feed intake was reduced by 100 and 60g/day in WB and C based diets, respectively, compared to diets 2–8. According to the broken-line, curvilinear plateau, and exponential models, highest BW gain was reached at Trp:Lys ratios of 16.8%, >19.7%, and >19.7% for BW based, and 18.0%, >20.9%, and >20.9% for C based diets, respectively. The respective ratios for the feed to gain ratio were 17.0%, 18.5%, and >19.7% and 19.9%, >20.9%, and >20.9% for WB and C based diets, respectively. The results confirm published ratios determined in WB based diets and indicate a slightly higher optimum ratio in C based diets. However, the mathematical model used for data analysis, the chosen response parameter, and the target performance level strongly affect estimates of the optimum dietary Trp:Lys ratio.


      PubDate: 2014-04-27T22:53:02Z
       
  • Conformation traits and their genetic and phenotypic associations with
           health status in young Swedish warmblood riding horses
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Lina Jönsson , Anna Näsholm , Lars Roepstorff , Agneta Egenvall , Göran Dalin , Jan Philipsson
      Health in horses is thought to be influenced by conformation traits, including limb deviations. As few studies on the subject are available, the relevance of selecting for specific conformation traits to improve health is uncertain. The objective was to determine the genetic variation in conformation and relationships between conformation and health status in young riding horses. Analyses included 8187 young horses independently examined for conformation and health, during the Swedish Riding Horse Quality Test (RHQT) for 4–5 year-old horses. Both descriptive conformation traits and assessment scores of conformation were studied. Phenotypic effects were estimated using single trait General Linear Models and heritabilities and genetic correlations using multi-trait linear animal models. Four major health indicators were constructed from the detailed veterinary examinations. Conformation assessment scores were all favourably related to at least one of 4 studied health traits, both phenotypically and genetically. Genetic correlations reached 0.75 between conformation scores for head-neck-body and locomotion examinations, including flexion tests, and 0.43 for limb scores and locomotion examinations. Best health status was found for an intermediate-sized horse, with a well-positioned neck, a light front, and no major limb deviations. This finding was consistent with the role of correct movements at trot. Among limb deviations stiff pasterns, toed-out or toed-in forelimbs, and small or large hock angles showed highest negative effects on health. However, the prevalence of limb deviations was generally low, thus only toed-in forelimbs and small joints had significant genetic correlations to impaired health. Heritabilities for withers height, cannon bone circumference and overall conformation scores (except for limbs), were medium to high (0.20–0.67, s.e. 0.03–0.04). For specific limb deviations, heritabilities were in the range of 0.01–0.15 (s.e. 0.01–0.02) on the observed scale, corresponding to 0.04–0.48 on the underlying quantitative scale. Heritabilities of conformation traits and favourable correlations to health indicate good opportunities for genetic improvement of conformation, and indirectly to some extent also of health. However, only limited improvements could be expected for the prevalence of some limb deviations, where frequencies are already low.


      PubDate: 2014-04-27T22:53:02Z
       
  • Can milk fat changes be predicted from nutrient flows in dairy cows'
           Design and evaluation of an empirical model
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): G. Maxin , J.L. Peyraud , P. Nozière , H. Rulquin , F. Glasser
      Most of the current feed evaluation systems used to estimate dairy cow requirements and formulate diets cannot predict the effects of dietary changes on milk composition, in particular on milk fat content (MFC) and milk fat yield (MFY) responses. Dietary changes alter dairy cow MFC and MFY through modifications in the supply of nutrients, which act as precursors or inhibitors of mammary fat synthesis. Taking into account the supply of nutrients could allow feed evaluation systems to predict milk composition responses to dietary changes. We described an empirical model based on nutrient flows to predict MFC and MFY responses to dietary changes. This model was built by coupling a set of published empirical equations estimating nutrient flows (acetate, propionate, butyrate, glucose and digestible protein) from dietary characteristics and the measured ruminal VFA proportions to another set of equations estimating the response of milk fat to the supply of these nutrients. The model was evaluated by comparing the predicted and observed MFC and MFY responses on three databases derived from published feeding studies in dairy cows. The databases compiled published trials involving a change in the forage-to-concentrate ratio (‘F:C ratio’ sub-database), a change in the carbohydrate source (‘CHO source’ sub-database) or a change in both F:C ratio and CHO source (‘ratio and source’ sub-database). Overall, the current version of the model did not accurately predict milk fat responses: the model did not enable to explain the MFC and MFY responses in the ‘CHO source’ sub-database (P>0.10 and R 2=0.02); in the ‘F:C ratio’ sub-database, agreement between observed and predicted responses was better (the slopes were not different from unity and were respectively 0.84 and 0.94 for MFC and MFY), but R 2 were low (R 2=0.36 for MFC and R 2=0.43 for MFY). In the ‘ratio and source’ database, MFY was quite correctly predicted (the slope was 0.93 and R 2=0.42), but not the MFC responses (P>0.10 and R 2=0.01). The mean errors of prediction for MFC were 2.61, 3.79 and 3.55g/kg, respectively in the ‘F:C ratio’, ‘CHO source’ and the ‘ratio and source’ sub-databases. The effects of several interfering factors related to cows, diets or experimental conditions were tested to explain differences between observed and predicted responses in each sub-database. They enabled to identify several potential sources of bias in the model: especially, bias in estimation of OM digestibility, bias in estimation of glucose effects, lack of the effects of fatty acids in the model. These constitute interesting ways to improve the model.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of probiotics and bremelain fermented soybean meal replacing fish
           meal on growth performance, nutrient retention and carcass traits of
           broilers
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Chun-Yi Li , Jin-Jenn Lu , Chean-Ping Wu , Tu-Fa Lien
      This study investigated the feasibility of dietary supplemental mixed probiotics and bromelain fermented soybean meal (FS) and the strength of fermented soybean meal (SFS) (adjusted amino acids and protein) to replace expensive fish meal for broilers, in order to reduce feeding cost. Trial 1 investigated the effects of adding different levels of mixed probiotics fermented solution and bromelain (a kind of protease extracted from pineapple) on the quality of fermented soybean meal. Trial 2 included (1) 4% fish meal (FM) as the control, (2) 6% wet fermented soybean meal (WFS), (3) 5% soybean meal (SBM), (4) 5% wet strengthened fermented soybean meal (WSFS) and (5) 4.5% dry strengthened fermented soybean meal (DSFS) groups. The best outcome of Trial 1 resulted from inoculation with a 34% fermented solution and 0.05% bromelain, and incubation at 34±0.5°C for a week. Results from Trial 2 showed that the growth performance in the FM group had a significantly better average body weight gain (BWG) and feed intake (P<0.05) compared to the SBM group. The relative spleen weight in the WFS, WSFS and DSFS groups was significantly higher than that in the SBM group (P<0.05). In conclusion, SBM replacement with FM has an adverse effect on growth performance; FS can improve this adverse effect. FS had no negative effects on the replacement of FM in the broiler diet, implying that with respect to economic issues, the FS has the potential to be used as a FM substitution.


      PubDate: 2014-04-27T22:53:02Z
       
  • Editorial Board
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163




      PubDate: 2014-04-27T22:53:02Z
       
  • Editorial Board
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163




      PubDate: 2014-04-27T22:53:02Z
       
  • Comparative genetic diversity analysis among six Indian breeds and English
           Thoroughbred horses
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): A.K. Gupta , Mamta Chauhan , Anuradha Bhardwaj , Neelam Gupta , S.C. Gupta , Yash Pal , S.N. Tandon , R.K. Vijh
      Genetic diversity analysis, population structure and relationship among six Indian horse (Kathiawari, Marwari) and pony breeds (Manipuri, Spiti, Zanskari and Bhutia), along with English Thoroughbred horses as an out group was carried out using 284 DNA samples with 48 polymorphic microsatellite markers. Allele number, observed and expected heterozygosity, polymorphism information content were estimated. These values were higher for all Indian breeds except Spiti ponies in comparison to Thoroughbred horses which indicated high genetic diversity in them. Mean number of alleles was maximum in Marwari horse breeds (10.06±0.36) followed by Bhutia, Zanskari, Manipuri, Kathiawari and Thoroughbred. The allelic count was the lowest in Spiti (5.52±0.42). Similar pattern was observed in terms of allelic richness also. An overall significant deficit of heterozygote (F is ) equal to 0.066 was observed in Indian horse and pony breeds. The mean values of F is ranged from 0.003 in Spiti to 0.132 in Marwari with mean of 0.065±0.040. The F st values ranged from 0.0512 (TKY394) to 0.2724 (COR018) with an overall genetic differentiation of 9.8% among breeds. The overall global deficit of heterozygote across populations (F it ) amounted to 15.98%. The estimates of F st between each pair of breeds revealed that genetic differentiation between Spiti and Thoroughbred (0.1729) was the maximum followed by Spiti and Kathiawari (0.1725) while Zanskari and Manipuri were the least differentiated (0.0379). Individual assignment indicated admixture in all the breeds except Thoroughbred horses. The neighbor-joining dendrogram using the allele sharing distance clearly defined clusters for most of the breeds, Indian horse and pony breeds clustered separately while Thoroughbred formed a separate out-group. The Bayesian analysis using STRUCTURE revealed three distinctive clusters of Indian horse and pony breeds, Kathiawari the most prominent cluster as horse breed, second of Zanskari, Spiti and Manipuri ponies and third one having Bhutia and a sub-population of Marwari horses. Clustering of one sub-population of Marwari with Bhutia indicated their common ancestries which need further investigations as both these are distinct at phenotypic level and geographically isolated. Kathiawari represents the oldest stock and has contributed in other Indian breeds. Similarity of Kathiawari and Marwari horses is attributed to contiguity of their breeding tracts.


      PubDate: 2014-04-27T22:53:02Z
       
  • Organic selenium increases PHGPx, but does not affect quality sperm in raw
           boar semen
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): S.M.M.K. Martins , A.F.C. De Andrade , F.G. Zaffalon , L.J. Parazzi , F.F. Bressan , S.M.P. Pugine , M.P. Melo , M.R. Chiaratti , C.T. Marino , E.R. Afonso , A.S. Moretti , R.P. Arruda
      This study assessed the effects of feeding organic selenium (Se) on sperm morphology, motility, membrane integrity and lipidic peroxidation, also on sperm ATP and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in raw semen of mature boars. Twelve boars were divided into three groups: Control, 0.3ppm sodium selenite, Inorganic, 0.5ppm sodium selenite and Organic, 0.5ppm Se yeast for 11 weeks. Organic diet presented a higher total sperm number (P<0.05) when compared to the inorganic treatment; however, no difference was observed regarding volume, sperm concentration, number of cells with plasma and/or acrosomal membrane integrity, membrane mitochondrial potential, ATP assay and Se concentration in seminal and blood content. Also, no difference was observed on motility parameters, sperm morphology and membrane peroxidation, however, PHGPx was influenced (P<0.05) in organic treatment. Thus organic Se feeding influenced none of the analyzed seminal characteristics in raw semen, except for PHGPx and total number of sperm.


      PubDate: 2014-04-27T22:53:02Z
       
  • Comparison of temperature fluctuations at multiple anatomical locations in
           cattle during exposure to bovine viral diarrhea virus
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): S.M. Falkenberg , J. Ridpath , B. Vander Ley , F.V. Bauermann , N.C. Burdick Sanchez , J.A. Carroll
      Rectal temperature is generally considered the “gold standard” for monitoring temperature changes associated with environmental, immunological or endocrine stimuli in cattle. With the development of new telemetry systems, other anatomical locations and methods can be utilized to help continuously monitor changes in temperature. The primary objective of this study was to compare basal body temperature obtained from multiple anatomical locations to rectal temperature readings during exposure of cattle to bovine viral diarrhea virus. Anatomically the locations chosen to compare body temperature values were the rectum, rumen, peritoneal cavity, and subcutaneous. Results from the study demonstrate that there were no differences (P>0.05) among body temperatures recorded at these distinct anatomical locations, and that the temperatures followed a similar response pattern. Advantages and disadvantages were also noted for each of the temperature devices used in the study. The ability to continuously monitor data at over the course of an infection provides the ability to assess signs of clinical illness without inducing changes associated with handling the animals to obtain temperature measurements. Efficiently determining the health status of an animal without introducing artificial changes in body temperature could aid in the development of alternative management practices that would help reduce the cost associated with medication, production losses due to unneeded handling, and more accurate diagnosis of disease.


      PubDate: 2014-04-27T22:53:02Z
       
  • Clinical lameness and risk factors in a Spanish Holstein population
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): M.A. Pérez-Cabal , R. Alenda
      Given the economical importance of lameness in dairy milk production, the presence or absence of clinical lameness and the associated risk factors were studied in a Spanish Holstein population. Lameness was diagnosed by veterinarians or farmers as visually abnormal gait. Up to 6 cases per lactation were considered in 6568 lactations of 3459 different cows with first calving between January 2005 and October 2011. Geographical area (region where herd is located) and parity number (primiparous and multiparous) were studied as risk factors, along with the following herd facilities: housing type, flooring, access to soil surface, presence or absence of a footbath, and periodical trimming. Seasonality of lameness was determined as season when first lameness event was diagnosed and lactation period (first 120 days or later) when first event occurred. Also milk, fat, and protein yield production were analyzed as risk factors. The association analyses were estimated using multivariate generalized linear models with a log link function. Lameness was diagnosed in 13.8% of cows and 8.7% of lactations, with multiparous cows being more prone than primiparous cows (odds ratio (OR)=1.50). Solid concrete was more beneficial than grooved concrete for primiparous cows (OR=0.67) as were freestalls as compared to cubicles, while no differences relating to housing system or flooring type were found for multiparous cows. Changes in walking surfaces led to the highest risk of lameness only for cows with two or more lactations (OR=1.33), where it was found to be more beneficial either always or never having soil surface available. Presence of footbaths was associated with reducing lameness occurrence in multiparous cows while periodical trimming was a useful preventive treatment for primiparous cows. Winter was the season of diagnosis of a first event with less probability of being recurrent for multiparous cows. No association with production traits were found either for primiparous or multiparous cows. Herd factor risks were therefore different for primiparous and multiparous. Young cows were less prone to lameness in herds with solid concrete floors and periodical trimming. However, walking on the same kind of surface throughout the lactation and the availability of a footbath prevented the occurrence of lameness in multiparous cows.


      PubDate: 2014-04-27T22:53:02Z
       
  • Using archaeol to investigate the location of methanogens in the ruminant
           digestive tract
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): C.A. McCartney , I.D. Bull , R.J. Dewhurst
      The quantification of archaeol, a methanogen membrane lipid, may provide an alternative method to estimate methanogen abundance. The focus of this study was to determine the location of methanogens in the ruminant digestive tract using this biomarker. Archaeol was quantified in samples obtained from four lactating cows with rumen cannulae that grazed on either white clover (WC) or perennial ryegrass (PRG) in a changeover design study with three 3-week periods. Faeces were collected over the final 5d of each period and total rumen contents (TRC) were obtained on the final 2 days (day 1: 9am; day 2: 3pm). Solid-associated microbes (SAM) and liquid-associated microbes (LAM) were also isolated from the TRC. Concentrations of archaeol in the TRC showed a significant diet by time interaction, which may be related to diurnal grazing patterns and different rumen conditions associated with PRG or WC diets. There was significantly more archaeol associated with SAM than LAM, which may reflect difficulties of methanogen proliferation in the liquid phase. Faeces had higher concentrations of archaeol than SAM and LAM which was unexpected, although, losses of methanogens may have occurred during isolation (i.e., attachment to protozoa and very small particles), or the methanogens associated with SAM may have been underestimated. There was no significant relationship between faecal and TRC archaeol concentrations. Finally, there was a significant positive relationship between rumen pH and concentrations of archaeol in SAM and LAM, which may be caused by pH and/or WC diet effects. In conclusion, archaeol is potentially a useful alternative marker for determining the abundance of methanogens in the ruminant digestive tract. This work has also highlighted the difficulties associated with methanogen quantification from microbial isolates, and the need for more representative rumen sampling in future studies.


      PubDate: 2014-04-27T22:53:02Z
       
  • Residual feed intake as selection tool in South African Bonsmara cattle
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Y. Steyn , E. van Marle-Köster , H.E. Theron
      In South African Bonsmara cattle, feed conversion ratio (FCR) is mostly used as a measure of feed efficiency in selection programs but has the disadvantage of being a ratio trait and unfavourably correlated to weight and mature size. Residual feed intake (RFI) overcomes both these disadvantages. The purpose of this study was to evaluate RFI as a potential trait in a selection programme by determining its correlations with growth related traits as well as other efficiency traits. Data of 5981 Bonsmara bulls that participated in centralised growth tests was analysed. In this study, RFI was calculated within contemporary groups of more than ten animals. The h 2 for RFI, FCR and KR were 0.27±0.02, 0.23±0.02 and 0.18±0.02 respectively. The genetic correlation between RFI and FCR, and RFI and KR were 0.65±0.04 and 0.12±0.07 respectively. Correlations approaching zero were estimated between RFI and shoulder height (SH), body length (BL), scrotal circumference (SC), average daily gain (ADG), weaning weight (WW) and metabolic mid-weight (MMW), and a strong correlation of 0.79±0.03 with daily feed intake (DFI). This study shows sufficient genetic variation for RFI to be considered by the Bonsmara breed as a measure of feed efficiency and confirms its independence from growth and size traits.


      PubDate: 2014-04-27T22:53:02Z
       
  • Construction of a cDNA library and identification of genes from Liaoning
           cashmere goat
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Mei Jin , Nian Liu , Songxue Yuan , Jun Piao , Fengqin Zhao , Yangle Qu , Tingting Zhang , Yanjie Wang
      We constructed a skin cDNA library of the Liaoning cashmere goat during follicle anagen. The recombination was over 89%. A total of 1986 expressed sequence tags (ESTs) were sequenced. After assembly, 1126 ESTs that were homologous to functionally characterized or hypothetical proteins were obtained. BLASTX searches found 904 ESTs that had strong matches to known proteins. More than 50% of the ESTs were similar to proteins that were annotated either as related to enzyme/catalytic activity (26.5%) or as being involved in cell activities, such as growth differentiation, proliferation, apoptosis, transportation, and signal transmission (25.9%). 1.2% of the ESTs were similar to proteins that were related to hair/hair follicle. By analyzing the structure of the unisequences, 81 full-length cDNA clones were identified, none of which had yet been identified in goat. We selected two full-length cDNA clones with predicted proteins, which were similar to dimethyladenosine transferase 1-like (DIMT1L) and coatomer protein complex, subunit zeta (ζ-COP). An analysis of the tertiary structure of the DIMT1L homolog showed that it had a methyltransferase domain. The ζ-COP was a short chain and had a simple tertiary structure. In order to study DIMT1L and ζ-COP genes expression, the semi-quantitative RT-PCR was used to detect whether DIMT1L and ζ-COP genes were expressed in heart, liver, spleen, lung, kidney tissues and in situ hybridization (ISH) to detect DIMT1L and ζ-COP genes expression location. Both DIMT1L and ζ-COP genes had high expression levels in heart and skin, and low levels in liver, kidney, lung and spleen. Moreover, DIMT1L and ζ-COP genes had a strong expression in the inner root sheath of the primary hair follicles (PF) and the secondary hair follicles (SF). The ζ-COP gene also had a strong expression in the surrounding tissue. In conclusion, we have successfully constructed a skin cDNA library from Liaoning cashmere goat during follicle anagen and characterized two genes. The cDNA library could become a valuable source to study the biology genetic characteristics of Liaoning cashmere goat and may provide an important platform for protecting genomic resources and improving the breed.


      PubDate: 2014-04-27T22:53:02Z
       
  • Relationship between stress-related exsanguination blood variables,
           vocalisation, and stressors imposed on cattle between lairage and stunning
           box under conventional abattoir conditions
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): J.K. Probst , A. Spengler Neff , E. Hillmann , M. Kreuzer , M. Koch-Mathis , F. Leiber
      Physiological and behavioural reactions of cattle to handling procedures in a commercial abattoir (electrical prodding actions and duration of the animals׳ stay in the stunning box) were evaluated and set in relation to sex, breed type, and carcass weight. A total of 192 cattle comprised of 45 bulls, 61 steers, and 86 heifers from different breed types (30 dairy breed, 70 beef breed, and 92 crossbreds) were observed from lairage to slaughter during one day. The frequency of electrical proddings and the waiting time in the stunning box was recorded for each individual. As a measure of a behavioural stress response, the number of vocalising animals was recorded. Exsanguination blood serum samples were analysed for cortisol, glucose, and lactate concentrations. Forty-nine animals received no electrical prods; 117 animals were prodded one to three times, and 24 animals received between 4 and 9 prods. Thirteen per cent of all animals were recorded as vocalisers. There was a trend (P=0.07) that heifers vocalised more than bulls and steers. Mean levels per ml of blood were 77.2ng cortisol (SE=68.8), 5.7μmol glucose (SE=1.3), and 6.7μmol lactate (SE=3.3). Cortisol concentrations were lower in bulls than in steers and in heifers (P<0.01), and concentrations above 90ng/ml were measured in 21.3% of the steers and 27.8% of the heifers, but not in the bulls. Lactate and glucose concentrations were not influenced by sex. Breed type had no influence on any of the stress-indicating traits. Prodding categories were not related with concentrations of the blood variables and the number of vocalising animals. A longer stay in the stunning box led to increased cortisol concentrations (P<0.05), but had no influence on lactate and glucose concentrations or on the number of vocalising animals. In conclusion, stress levels were relatively high in the present case, but it was not possible to relate the stress indicators unequivocally to the potential factors of influence investigated.


      PubDate: 2014-04-27T22:53:02Z
       
  • Complete replacement of soybean meal in pig diets with hydrolyzed feather
           meal with blood by amino acid supplementation based on standardized lleal
           amino acid digestibility
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): S.D. Brotzge , L.I. Chiba , C.K. Adhikari , H.H. Stein , S.P. Rodning , E.G. Welles
      The current study was conducted to determine the possibility of replacing soybean meal (SBM) in finisher pig diet completely with hydrolyzed feather meal (FM) with blood by supplementing with appropriate amino acids (AA) based on standardized ileal digestible (SID) AA in FM. Corn–SBM, positive control (POS) diets were formulated to contain 6.6 and 5.2g true ileal digestible (TID)Lys/kg to satisfy the requirements during the finisher-1 and finisher-2 phases, respectively. Corn–FM negative control (NEG) diets were formulated to be iso-N and iso-caloric to the POS diets. The NEG diets were supplemented with Lys and Trp to alleviate AA deficiencies based on TID AA values in FM reported by the NRC in 1998 (NRC). In addition, the NEG diets were supplemented with Lys and Trp to alleviate AA deficiencies based on the determined SID AA in FM (SID). When pigs weighed 50.0±2.9kg, 32 gilts and 32 castrated males (2 gilts or 2 castrated males/pen) were randomly assigned to 1 of 4 finisher-1 diets with 4 gilt pens and 4 castrated male pens/diet, and they were switched to finisher-2 diets when the average pen weight reached 79.0±2.0kg. Pigs had ad libitum access to feed and water throughout the study. At the end of the finisher-2 phase (107.7±3.3kg), blood samples were collected to determine serum metabolite profile and pigs were slaughtered to assess carcass characteristics. Pigs fed the POS diets ended to have greater overall average daily feed intake (ADFI; P =0.083) and had greater total Lys intake (P =0.029) than those fed the SID diets, which may have resulted in a tendency for slightly greater average daily gain (ADG; P =0.094) in pigs fed the POS diets. However, there was no difference in the efficiency of feed or Lys utilization. Pigs fed the SID diets tended to have greater gain:feed (G:F; P =0.057) and had greater gain:total Lys intake (P<0.001) than those fed the NRC diets. Pigs fed the POS diets tended to have greater ADFI (P =0.079) and had greater ADG (P<0.001) and G:F (P<0.001) than those fed the NEG diets, but, as expected, they had lower gain:total Lys intake (P<0.001) mostly because of the increased total Lys intake (P<0.001). Serum glucose was not affected by dietary treatments. Pigs fed the POS diets had greater urea-N (P =0.003) and lower cholesterol (P =0.002) than those fed the SID diets. As expected, pigs fed the NEG diet had reduced total protein (P<0.001) and increased urea-N (P =0.001), triglyceride (P<0.001), and cholesterol (P<0.001) compared with those fed the POS diets. Pigs fed the POS diets had greater fat-free lean gain (P =0.020) that those fed the SID diets, but similar loin muscle area, fat-free carcass percentage, and efficiency of fat-free lean gain. Results indicated that pigs fed the SID diets utilized feed and Lys as efficiently as those fed the POS diets, but they had slightly reduced body weight and fat-free lean gain, perhaps, because of slightly reduced intake of feed and total Lys, as well as other AA.


      PubDate: 2014-04-27T22:53:02Z
       
  • Influence of Salix babylonica and Leucaena leucocephala leaf extracts on
           ruminal fermentation characteristics, urinary purine derivative excretion
           and microbial protein synthesis of lambs
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): P. Hernandez , A.Z.M. Salem , S. López , X.Z. Sun , R. Rojo , L.M. Camacho , M.M.Y. Elghandour , M. Gonzalez-Ronquillo
      Sixteen growing Katahdin×Pelibuey lambs (24±0.3kg body weight) were used to study the effects of oral administration of extracts of Salix babylonica (SB) and Leucaena leucocephala (LL) leaves on ruminal pH, total and individual volatile fatty acids (VFA) and NH3-N concentrations, as well as ruminal protozoal counts, urinary purine derivatives (PD) excretion and estimated microbial protein synthesis. Lambs were fed a total mixed ration (TMR) containing 219 and 141gkg−1 of CP and NDF, respectively. Four treatments (4lambs/treatment) were Control (no extract added), SB (SB extract at 30mld−1), LL (LL extract at 30mld−1) and SBLL (mixture of SB at 15mld−1+LL at 15mld−1). Extracts were administered orally to each lamb before the morning meal daily. Measurements were on days 22 (P1), 43 (P2) and 63 (P3) of the experiment. Ruminal pH increased (P=0.014) with SBLL extract and decreased with SB. The ratio of acetate to propionate was higher (P=0.042) with SBLL compared to the control. Ruminal NH3-N concentration was not affected by extract administration (P=0.309) or experimental period (P=0.087). Protozoal counts were not affected (P=0.489) by extract addition but decreased (P<0.001) in P3 compared with P1 and P2. Uric acid concentration increased (P<0.001) with individual extracts of SB and LL compared with the control or SBLL. Excretion of other purine derivatives (allantoin, xanthine, and hypoxanthine), creatinine and microbial protein synthesis were not changed (P>0.05) by extracts administration. Overall, oral administration of S. babylonica and L. leucocephala extracts, or their 1:1 mixture, to lambs for 63d had only minor effects on ruminal fermentation, urinary purine derivative excretion and microbial protein synthesis.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of chopping grass silage and mixing silage with concentrate on
           feed intake, dietary selection, chewing activity and faecal particle size
           of ewes in late pregnancy and early lactation
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): Carl Helander , Peder Nørgaard , Ali Reza Jalali , Elisabet Nadeau
      The effects of chopping grass silage and of mixing grass silage and concentrate on feed intake, dietary selection, chewing behaviour and faecal particle size in pregnant and lactating ewes were studied. The three experimental diets used in both experiments were: 1. un-chopped grass silage and 0.8kg concentrate, fed separately (US); 2. chopped grass silage and 0.8kg concentrate, fed separately (CS); and 3. chopped grass silage mixed with concentrate to the same forage:concentrate ratio as in the CS treatment (CM). Twin bearing/suckling ewes (n=7 per treatment) were penned and fed individually during the experiments. The silages used in Experiments 1 and 2 contained 10.9 and 11.4MJ ME/kg dry matter (DM), 139 and 193g CP/kg DM, and 580 and 483g NDF/kg DM, respectively. All measurements and recordings were carried out during two four-day periods in each experiment, one in late pregnancy and one in early lactation. Daily DM intake increased from late pregnancy to early lactation by 0.7 and 1.7kg in Exp. 1 and Exp. 2, respectively, averaged over treatments (P<0.0001). Chopping silage decreased dietary selection of feed particles with low NDF content in both periods and in both experiments (P<0.0001). Pregnant and lactating ewes fed chopped silage, separately or mixed with concentrate, spent less time eating daily compared with ewes fed un-chopped silage. Ewes also increased their daily eating time from pregnancy to lactation in Exp. 1 and, averaged over periods, increased rumination time per day and per kg DM intake in Exp. 1 and 2, compared with the ewes fed un-chopped silage. In conclusion, chopping silage decreased dietary selection, eating time and eating:rumination ratio and increased rumination time in pregnant and lactating ewes with large body size and high milk production. Mixing highly digestible grass silage with concentrates increased proportion of large particles in faeces. In early lactation, feed intake and proportion of large particles in faeces were higher, whereas eating, rumination and total chewing time per kg DMI were lower than in late pregnancy, suggesting more efficient fibre degradation in pregnancy than in lactation.


      PubDate: 2014-04-27T22:53:02Z
       
  • The impact of space allowance on productivity performance and Salmonella
           spp. shedding in nursery pigs
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Nenad Stojanac , Ognjen Stevančević , Aleksandar Potkonjak , Božidar Savić , Ivan Stančić , Vuk Vračar
      The object of this study was to determine the effect of the area available per piglet, during the nurturing phase, on production performance and presence of Salmonella spp. Testing was performed on two farrow-to-finish farms over a period of two years. The study was carried out in three variants: 0.16m2, 0.25m2 and 0.32m2 of floor space per piglet. Pooled faeces samples, which were tested for the presence of Salmonella spp., were collected three times during the nurturing stage: 7, 21 and 35 days after weaning. The piglets which had the lowest spatial area available (0.16m2) had average daily gain (ADG) significantly lower (P<0.05), and feed conversion ratio (FCR) higher than piglets with 0.25m2 and 0.32m2 of floor space available. Morbidity and mortality were significantly higher in piglets with 0.16m2 of floor space available, compared to piglets housed on larger floor spaces, for both farms examined. The overall presence of Salmonella spp. was 6.2% (19/306). Out of 19 Salmonella-positive faecal samples, 15 were from piglets with 0.16m2 of floor space available (78.9%). The results showed that holding piglets in an area smaller than recommended has no economic justification and may imposes a higher risks of infection of piglets.


      PubDate: 2014-04-27T22:53:02Z
       
  • Phyto-oestrogens and their metabolites in milk produced on two pastures
           with different botanical compositions
    • Abstract: Publication date: May 2014
      Source:Livestock Science, Volume 163
      Author(s): S.A. Adler , S. Purup , J. Hansen-Møller , E. Thuen , A.-M. Gustavsson , H. Steinshamn
      Phyto-oestrogens are a group of secondary plant metabolites that may bind to oestrogen receptors and exert oestrogenic or anti-oestrogenic effects in humans and can protect against cancer diseases. When ingested by dairy cows, phyto-oestrogens can be metabolised and transferred to the milk. The objective of this study was to assess the effects of grazing a recently established pasture containing red clover (Trifolium pratense L.) and an older pasture containing a variety of sown and unsown plant species on milk concentrations of phyto-oestrogens. Sixteen Norwegian Red dairy cows [mean (standard deviation); body weight 599 (45.1)kg, stage of lactation 73 (15.0) d in milk, milk yield 29.9 (2.90) kg/d at the start of the experiment] were divided into two groups and grazed either a short-term pasture (SP) or a long-term pasture (LP). The SP was representative of organically managed leys in Norway, which are frequently, approximately every third year, renewed by soil tillage and seeding, whereas LP was representative of organically managed grasslands that are less frequently renewed. The SP contained meadow fescue (Festuca pratensis Huds.) (mean 34%), timothy (Phleum pratense L.) (mean 19%), red clover (mean 28%), shepherd׳s-purse (Capsella bursa-pastoris (L.) Medik.) (mean 6%), pineappleweed (Matricaria matricarioides Porter ex Britton) (mean 5%) and scentless mayweed (Tripleurospermum perforatum (Mérat) Laínz) (mean 4%), and LP contained mainly white clover (Trifolium repens L.) (mean 21%), smooth meadowgrass (Poa pratensis L.) (mean 19%), timothy (mean 17%), meadow fescue (mean 15%), perennial ryegrass (Lolium perenne L.) (mean 6%), tufted hairgrass (Deschampsia cespitosa (L.) P. Beauv.) (mean 5%), northern dock (Rumex longifolius DC.) (mean 4%), common couch (Elytrigia repens (L.) Desv. Ex Nevski) (mean 4%), red clover (mean 3%) and dandelion (Taraxacum spp.) (mean 3%). In addition to a daily pasture allowance of 20kg dry matter per cow, supplements of 3.0kg barley (Hordeum vulgare L.) concentrate were fed. Herbage, concentrates and milk was sampled during the last week of three experimental periods and analysed for phyto-oestrogens using LC-MS/MS technology. Herbage from SP had 19 times higher concentration of isoflavones than herbage from LP, whereas only small differences were found for lignans. Milk produced on SP had 14 times higher concentrations of the mammalian isoflavonoid equol, and the concentrations of equol were higher than found in most other studies. This study confirms that grazing pastures containing red clover increases concentrations of isoflavones and especially equol in bovine milk compared to grazing pastures with other botanical composition. The higher milk concentrations of the lignan metabolite enterodiol in milk from SP compared to LP could not be related to differences in intake of the analysed lignans and may therefore be related to unidentified lignans.


      PubDate: 2014-04-27T22:53:02Z
       
  • Enteric and manure-derived methane emissions and biogas yield of slurry
           from dairy cows fed grass silage and maize silage with and without
           supplementation of rapeseed
    • Abstract: Publication date: Available online 18 April 2014
      Source:Livestock Science
      Author(s): A.L.F. Hellwing , M.R. Weisbjerg , H.B. Møller
      The aim of this study was to investigate the effect of three different dietary strategies on milk production and composition, enteric CH4 emissions, slurry storage losses of CH4 and total emissions of CH4 with and without biogas production. Fifty-four cows were allocated to three diets according to parity and days in milk. Two diets were based on maize silage with (MS+) or without (MS-) supplementation of crushed rapeseed, and the third diet was based on late cut grass silage without supplementation of crushed rapeseed (GS-). Dry matter intake, milk yield and composition were measured. Enteric methane emissions were measured on 24 cows by means of indirect calorimetertri. Slurry was collected the last 10 days of the experiment. Ultimate biogas yield, CH4 emissions at different storage temperatures and yield in a thermophilic biogas digester were determined for the three slurries. Dry matter intake was 22.5kg/day on MS- and MS+ which was significantly higher than the 20.7kg/day on GS-. Yield of energy corrected milk (ECM) was 2.8 and 2.5kg higher on MS+ compared with GS- and MS-, respectively. Enteric CH4 emissions related to dry matter intake or gross energy intake were highest for GS-. Supplementation of crushed rapeseed did not affect enteric CH4 emissions. Ultimate biogas yield and yield of CH4 in the digester were higher for MS+ and MS- than for GS-. Storage emissions from slurry increased with increasing storage temperature. The average total CH4 per kg ECM for the three treatments (mean±standard deviation) was 25.3±2.5, 26.8±3.3 and 29.0±4.2L CH4/kg ECM if manure was stored at 10°C, 15 °C or 20 °C, respectively. When the slurry was digested in a laboratory scale biogas plant, the lowest total CH4 emissions per kg ECM were observed for MS+ (20.5L CH4/ECM) and the highest for GS- (24.3L CH4/ECM) corresponding to the enteric emissions of CH4. It was found that MS+ had a higher yield and a lower milk fat concentration than MS- and GS-. Although MS+ had a lower milk fat concentration, the ECM yield was significantly higher for MS+ than for the two other diets. It was furthermore concluded that feed ration induced reductions in enteric methane emissions might be counteracted or complemented by changed methane emissions from slurry storage. The slurry biogas yield was highest (per kg ECM) from cows fed MS+ which also gave the lowest total methane emissions per kg ECM.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of sorbitol or an antimicrobial agent on performance, diarrhea,
           feed digestibility, and organ weight of weanling pigs
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Danilo do Prado Perina , Maicon Sbardella , Carla de Andrade , Bernardo Berenchtein , Leonardo Willian de Freitas , Cristina Román Amigo , Valdomiro Shigueru Miyada
      The purpose of this study was to evaluate growth performance, incidence of diarrhea, apparent digestibility of nutrients and energy, and organ weight in weanling pigs fed diets with graded levels of sorbitol (C6H14O6) or antimicrobial growth promoter (chlorhydroxyquinoline). One hundred and twenty weanling pigs (6.22±0.28kg) were used in a randomized complete block design with 5 treatments, 8 replications, and 3 pigs per pen. The treatments were diets containing 0 (basal), 1.0, 1.5, and 2% sorbitol, and the basal diet with 120ppm of chlorhydroxyquinoline. Increasing dietary sorbitol levels reduced linearly body weight (BW) at d 27 of experiment (R 2=0.64; P=0.019), whereas no effects of the dietary sorbitol levels were observed on growth performance during the periods of 1 to 6, 6 to 13, 27 to 40, and 1 to 40d of experiment. Antimicrobial reduced (P<0.001) BW and gain to feed ratio (P≤0.031), from 13 to 27, 27 to 40, and 1 to 40d, with no effect on average daily feed intake. No effects of sorbitol or antimicrobial were observed on the incidence of diarrhea, apparent digestibility, and organ weights. Results indicated that sorbitol would not appear to have the properties of a prebiotic to improve growth performance. Overall, dietary sorbitol added up to 2% in complex weanling pig diets did not affect growth performance, incidence of diarrhea, apparent digestibility of nutrients, and organ weight, whereas the antimicrobial agent, chlorhydroxyquinoline, adversely affected growth performance.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effect of dietary field pea (Pisum sativum L.) supplementation on growth
           performance, and carcass and meat quality of broiler chickens
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): V. Dotas , V.A. Bampidis , E. Sinapis , A. Hatzipanagiotou , K. Papanikolaou
      In an experiment with 480 one-day-old male broiler chickens, the effect of partial replacement of soybean meal and corn with raw field peas (FP; Pisum sativum L.) on growth performance and carcass and meat quality was determined. In the 42-d experiment, broiler chickens were allocated to 5 dietary treatments: FP-none, FP-low, FP-medium, FP-high, and FP-very high with 4 pens per treatment and 24 broiler chickens per pen, and received a diet ad libitum. The experiment was divided into 3 periods: starter period (1–14d of age), grower period (15–28d of age), and finisher period (29–42d of age). In all 3 periods, the diets for treatment FP-none had no FP (control), while those for treatments FP-low, FP-medium, FP-high, and FP-very high included 40, 80, 120, and 160gFP/kg, respectively, during the starter period, 60, 120, 180, and 240gFP/kg, respectively, during the grower period, and 120, 240, 360, and 480gFP/kg, respectively, during the finisher period. Replacement of soybean meal and corn with up to 480gFP/kg of diet resulted in similar productive performance. Moreover, carcass yield traits, skin color, and chemical composition were not affected by feeding diets with increasing levels of FP. Some differences (P<0.05) were observed in fatty acid distribution in total lipids of breast- and leg muscles, but the ratio of saturated to unsaturated fatty acids remained unaffected. In conclusion, depending on the age, inclusion levels up to 480g raw FP/kg can be used as an alternative protein and energy source to replace soybean meal and corn in broiler chicken diets.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of black cumin seed (Nigella sativa L.), a probiotic, a prebiotic
           and a synbiotic on growth performance, immune response and blood
           characteristics of male broilers
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Hossein A. Ghasemi , Niloofar Kasani , Kamran Taherpour
      This study was performed to investigate and compare the effect of different feed additives on growth performance, slaughter parameters, immune response, leukocyte profile and blood biochemical parameters of broilers. A total of 350 day-old male broiler chickens (Ross 308) were randomly assigned to seven treatments with five replicates each (10 chickens per replicate). Chickens were fed either a corn-soybean meal basal diet (control) or the basal diet supplemented with 5g/kg black seed (BS1), 10g/kg black seed (BS2), 20g/kg black seed (BS3), 1g/kg probiotic (Pro), 1g/kg prebiotic (Pre) or 1g/kg synbiotic (Syn). Average body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) of broilers were determined during the starter (0 to 10 days), grower (11 to 28 days) and finisher (29–42 days) periods, and also for the total experimental period (0–42 days). Three chickens per replicate were randomly selected to evaluate a cutaneous basophil hypersensitivity reaction to phytohaemagglutinin-P (PHA-P) on days 35 and 36. Blood samples (2 samples per replicate) were taken for measuring antibody responses (days 28 and 42), and also for hematological and biochemical analysis (day 42). After 6 weeks, BWG was higher for Syn-fed chickens compared with control group (P<0.05). From 0 to 42 days, FCR was improved by diets BS2, Pro and Syn by approximately 6.3, 6.3 and 7.3% respectively, compared to that of the control group (P<0.05). The toe web swelling, as cell mediated response to PHA-P, in the chickens fed diets BS3 and Syn was respectively 30.5 and 27.1% greater than in chickens fed control diet (P<0.05). All diets, except diets BS1 and BS2, increased primary antibody response against sheep red blood cell (SRBC) at 28 days (P<0.05). Moreover, broilers fed diets BS3, Pro and Syn showed the higher secondary anti-SRBC titers and lower plasma triglyceride, cholesterol and low-density lipoprotein cholesterol levels at 42 days (P<0.05). Other measured parameters, including FI, slaughter parameters, leukocyte profile, heterophil to lymphocyte ratio and plasma glucose and high-density lipoprotein cholesterol levels were not affected by the treatments (P>0.05). In conclusion, dietary supplemented with probiotic, synbiotic or 10 to 20g/kg black seed improved FCR of broilers and improved plasma lipid profile and antibody-mediated immunity. These findings justify further investigations to evaluate the efficacy of these additives before field application.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effect of dietary starch source on growth performances, digestibility and
           quality traits of growing pigs
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): S. Doti , J. Suárez-Belloch , M.A. Latorre , J.A. Guada , M. Fondevila
      Barley, rice, maize and peas as starch sources were tested to study if differences in glycemic index may affect feed utilization, productive performances and quality traits for growing pigs. Four experimental diets were formulated to include 420g starch/kg, provided by barley, barley/broken rice, barley/maize or barley/peas combinations (diets coded B, R, M and P, respectively). A 45% of total starch from diets R, M and P was provided by broken rice, maize or peas. The in vitro characterization of feeds showed that the rapidly digestible starch fraction was highest for R (P<0.001) and no differences were recorded among the other diets, whereas the slowly digestible fraction was higher for B and M than for R (P<0.01) and that higher than for P (P<0.01). Then the resistant starch fraction was higher for P than for B and M (P<0.001) and those higher than for R (P<0.001). The rate of glucose release was fastest with R (P<0.001), and estimations of glycemic index were highest for R and lowest for P (P<0.001). For the in vivo trial, a total of 72 Duroc×(Landrace×Large White) crossbred gilts, with 63.0±4.55kg body weight (116±3days of age) was used. Statistical trends (P model<0.10) were observed for ADG and FCR; gilts fed diet P grew faster (P<0.05) and had a lower FCR (P<0.05) than those fed diet R. The apparent organic matter digestibility for diets R and P was lower than for diet B (P<0.001) but higher than for diet M (P<0.01). Similarly, the apparent crude protein digestibility was higher with diet R than with diet M (P<0.01). Gilts consumed from 32% to 40% of available feed within the first 2h after offering, then the rate dropped from 2 to 4h (P<0.05) and was virtually nil from 10 to 12h for all diets. There was a limited influence of diet on carcass and meat characteristics but the intramuscular fat from pigs fed B showed higher (P<0.001) total saturated fatty acids and lower (P<0.001) total monounsaturated fatty acid contents than that from pigs fed M. It can be concluded that the pattern of gut digestion of the starch source may affect backfat thickness and growth performance of gilts, with scant effect on meat quality.


      PubDate: 2014-04-27T22:53:02Z
       
  • Diverse effects of linseed oil and fish oil in diets for sows on
           reproductive performance and pre-weaning growth of piglets
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): S. Tanghe , J. Missotten , K. Raes , J. Vangeyte , S. De Smet
      Perinatal mortality of piglets means a serious loss for the pig industry. Therefore, finding strategies to decrease stillbirths and increase piglet vitality is crucial. Supplementing the gestation and lactation diets with n−3 polyunsaturated fatty acids (PUFA), and especially docosahexaenoic acid (DHA), can be beneficial, as these PUFA are essential for the development of the foetus. Docosahexaenoic acid can be directly supplied from the maternal diet through addition of fish oil, or it may result from the conversion of dietary precursors such as alpha-linolenic acid, e.g. by addition of linseed oil. Until now, studies assessing the effects of n−3 PUFA on sow reproduction give equivocal results. Therefore, this study aimed to examine the effects of linseed oil and fish oil in the maternal diet of a large number of sows (734 sows in total) on their reproductive performance in the current and subsequent gestation. Furthermore, the effect of diet on the farrowing process, piglet weight and vitality was analysed. From day 45 of gestation and during lactation, sows were fed a palm oil diet or one of the six n−3 PUFA diets, each containing different concentrations (0.5%, 1% or 2%) of linseed oil, fish oil or their combination. Sows fed linseed oil had 0.9 more live born piglets (P=0.02) and 0.5 more weaned piglets (P=0.02) compared to fish oil fed sows. In the subsequent gestation, linseed oil fed sows had 1.3 and 1.5 more live born piglets compared to sows fed fish oil (P=0.006) or palm oil (P<0.001), respectively. No dietary effects were observed on piglet birth weight and litter weight, but linseed oil supplementation resulted in a higher piglet weight and litter weight at 5 days of age, compared to piglets from sows fed fish oil (P=0.04 and P=0.02, respectively) or palm oil (P=0.02 and P=0.002, respectively). Adding n−3 PUFA to the maternal diet had no effect on piglet vitality, but it increased the duration of farrowing (P=0.05).


      PubDate: 2014-04-27T22:53:02Z
       
  • Selection for morphology, gaits and functional traits in Lusitano horses:
           II. Fixed effects, genetic trends and selection in retrospect
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): A.A. Vicente , N. Carolino , J. Ralão-Duarte , L.T. Gama
      Mixed model procedures were used to analyze morphology and gaits records collected in about 18,000 Lusitano horses from 900 studs, over a period of 43 years, and functional records collected since 1998, to carry-out a critical assessment of the fixed effects and selection practices followed in this breed. Fixed effects considered in the analysis of morphology (head/neck, shoulder/withers, chest/thorax, back/loin, croup, legs and overall impression), gaits and final score (computed by summing partial morphological and gaits scores) were stud, year, sex, inbreeding and age. Functional traits analyzed were the scores obtained in working equitation dressage (WEDT) and maneability (WEMT) trials and in classical dressage (CD), where fixed effects were event, level of competition, sex, inbreeding and age. Phenotypic trends were moderate over the period analyzed, with a slight increase in height at withers, and a decline in final score. Nevertheless, differences among years were mostly environmental. Males received lower scores for almost all morphological and gaits traits except croup, with a difference of about −1.7 points for final score relative to females. Sex differences were small for functional traits, with general advantage of males in WEMT and CD, and a disadvantage in WEDT. Considerable differences were detected among studs, especially in their environmental effects but also in mean estimated breeding value (EBV), for morphology, gaits and functionality. The environmental effect of competition level in CD resulted in a progressively lower scoring as the competition became more difficult, while for WEMT the pattern was opposite and differences were minor for WEDT. Inbreeding depression was observed for all morphological and gait traits, but the magnitude of its impact was very small for all traits analyzed, never exceeding −0.1% of the mean per 1% inbreeding. Still, for functional traits the effect of inbreeding was negligible. The EBV for morphology, gaits, WEMT and WEDT show considerable variability, indicating that selection can be effective. For CD, however, the distribution of EBV was narrower. The genetic trend was positive but moderate for all traits, and it was slightly higher for head and neck, overall impression, gaits and final score. As a percentage of the mean, these traits and working equitation trials showed the highest responses, which in the best cases did not exceed 0.2% of the mean per year. Genetic selection differentials and the corresponding selection intensities were very modest for all traits analyzed, with a slightly higher intensity in sires when compared to dams.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of dietary flaxseed meal on production performance, egg quality,
           and hatchability of Huoyan geese and fatty acids profile in egg yolk and
           thigh meat from their offspring
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): W. Chen , Y.Y. Jiang , J.P. Wang , Y.Q. Huang , Z.X Wang
      Effects of dietary flaxseed meal (FSM) on production performance, egg quality, hatchability, and fatty acids profiles in egg yolks of geese and thigh meat from their offspring were studied in a 35-d study. A total of 288 female Huoyan geese (28-wk-old) were divided into 4 experimental diets containing FSM at 0 (control), 50, 100, and 150g/kg. There were 9 replicate pens per treatment with 8 geese per replicate pen. The total number of eggs produced (linear, P=0.04) and feed efficiency were greater (linear, P=0.04) in FSM containing groups than control diet. The inclusion of FSM in the geese diet linearly decreased the concentration of palmitic acid (linear, P=0.02) and saturated fatty acid (linear, P=0.05) in egg yolk, whereas the contents of C18:3n-3 (linear, P=0.04), C22:6n-3 (quadratic, P=0.05), total polyunsaturated fatty acids (PUFA; linear, P=0.01), and total n-3 PUFA (linear, P=0.01) were enhanced as the FSM levels increased. The arachidonic acid concentration (P=0.05) and n-6/n-3 ratio (P<0.05) also linearly decreased as the FSM inclusion level increased. At the end of the 35-d breeder experiment, all hatching eggs laid in 6 consecutive days in each group were collected and incubated. In 1-d-old goslings, the inclusion of FSM linearly decreased C16:0 (P=0.03) and total saturated fatty acid (P=0.04) concentrations in thigh meat. The contents of C18:3n-3 increased (linear, P=0.01), whereas C20:4n-6 decreased (linear, P=0.01) in FSM supplemented groups compared to control group. The concentrations of PUFA and total n-3 PUFA were linearly increased (P=0.04 and 0.01, respectively) and the n-6/n-3 ratio decreased linearly (P=0.02) as the FSM levels increased. In conclusion, dietary addition of FSM up to 150g/kg levels improved the egg production without any effect on egg quality and breeding performance. Moreover, feeding FSM to geese can increase the n-3 fatty acids concentration in egg yolk and deposition in the offspring in a dose-dependent manner.


      PubDate: 2014-04-27T22:53:02Z
       
  • Effects of Lactobacillus johnsonii XS4 supplementation on reproductive
           performance, gut environment, and blood biochemical and immunological
           index in lactating sows
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): J. Wang , H.F. Ji , C.L. Hou , S.X. Wang , D.Y. Zhang , H. Liu , D.C. Shan , Y.M. Wang
      In this study, the effects of Lactobacillus johnsonii XS4 feed supplementation on reproductive performance, gut environment, and blood biochemical and immunological index of sows were investigated. A total of 32 sows (France large white) were allotted into two dietary treatments: Control Group sows received basal diet and Experiment Group received the same diet supplemented with L. johnsonii XS4 (6.0×109 CFU/kg of diet). Treatment started from the day of allocation (90th day of pregnancy) up to the weaning day (25th day of lactation). Homogeneity of the groups was satisfied with regard to parity. From the results it was evident that L. johnsonii XS4 supplementation of the feed improved production performance as shown by the significantly increased litter weight at birth (14.97 vs. 13.08kg, P<0.05), 20 d litter weight (54.9 vs. 49.23kg, P<0.01), the number of piglets at weaning (10.31 vs. 9.43, P<0.05) and weaning litter weight (66.73 vs. 59.18kg, P<0.05). A positive trend was also noticed as regard to the reduction in the back fat thickness during lactation in terms of numerical lesser in the Experimental Group compared with the Control Group (0.79 vs. 1.05mm, P>0.05). The viable count of fecal flora (LAB, E. coli, and S. aureus) revealed no significant differences between the sows of the two groups. Moreover, the supplementation of L. johnsonii XS4 has significant effect on certain blood parameters of sows demonstrating significant increase in serum IgG levels (28.52 vs. 24.87mg/ml, P<0.05) and decrease in alanine aminotransferase concentrations (28.09 vs. 33.92 IU/dl, P<0.01). It is concluded that administration of L. johnsonii XS4 in diets during the end of pregnancy and during lactation had positive effects on the performance of sows.


      PubDate: 2014-04-27T22:53:02Z
       
  • Productive performance, biochemical and hematological traits of broiler
           chickens supplemented with propolis, bee pollen, and mannan
           oligosaccharides continuously or intermittently
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): Y.A. Attia , A.E. Abd Al-Hamid , M.S. Ibrahim , M.A. Al-Harthi , F. Bovera , A.Sh. Elnaggar
      The aim of this study was to compare the effect of different dietary supplements (bee pollen, BP; propolis, Pro; and mannan oligosaccharides, MOS) administered continuous or intermittent on productive performance and physiological traits of broiler chickens. A total of 324 unsexed 1-d-old Arbor Acres broiler chickens were divided among 9 dietary treatments with 6 replicate cages per treatment and 6 broiler chickens per cage, assigning experimental units to treatments randomly. Broiler chickens were assigned to the following starter and grower dietary treatments: basal control with no supplementation or basal control diets supplemented with 300mg BP (BP), 300mg Pro (Pro), 300mg BP and 300mg Pro (BP+Pro), and 0.5g MOS/kg. Each treatment group was divided into 2, in which the additives were administrated continuous or intermittent. The broiler chickens were vaccinated at d 7, 10, 14, and 21 of age. In the continuous treatment groups, supplementations were given from d 0 to 35, whereas in the intermittent treatment groups, the administration protocol was the following: 3 consecutive days before the day of vaccination (4, 5 and 6; 7, 8 and 9; 11, 12 and 13; and 18, 19 and 20d of age); on the day of vaccinations and 1d after each vaccination (d 8, 11, 15 and 22d of age). Thus, supplements were administered for 17 days as 7, 8 and 11d of age were overlapped because of the vaccination on 7 and 10d of age. All the supplements administered continuously or intermittently increased (P<0.05) body weight gain (average 1856 vs. 1641g) and improved (P<0.01) feed conversion ratio (average 1.88 vs. 2.24) during the entire period of the study in comparison to the un-supplemented control treatment. Also, dressing percentage was increased (P<0.05) in all the supplemented treatments compared with the control treatment (an average 70.9% vs. 68.9%). There was no synergistic effect of BP and Pro on growth performance, indicating that either of them is adequate. In general, the natural growth promoters increased red blood cells and hemoglobin (P<0.012) and decreased triglycerides, cholesterol, urea-N, and creatinine (P<0.008) as well as aspartate aminotransferase (P=0.047) in broiler chickens. Supplementing BP, Pro, or MOS continuously or intermittently was equally effective in increasing growth performance and dressing percent of broiler chickens.


      PubDate: 2014-04-27T22:53:02Z
       
  • Editorial Board
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164




      PubDate: 2014-04-27T22:53:02Z
       
  • Editorial Board
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164




      PubDate: 2014-04-27T22:53:02Z
       
  • Selection for morphology, gaits and functional traits in Lusitano horses:
           I. Genetic parameter estimates
    • Abstract: Publication date: June 2014
      Source:Livestock Science, Volume 164
      Author(s): A.A. Vicente , N. Carolino , J. Ralão-Duarte , L.T. Gama
      Genetic parameters were estimated for morphology, gaits and functional traits in Lusitano horses by uni- and multivariate animal models. Morphological traits considered in the analyses were partial scores attributed to up to 18,076 horses at the time of registration in the studbook and included head and neck, shoulder and withers, chest and thorax, back and loin, croup, legs and overall impression, plus a final score computed by summing the partial morphological scores and the gaits score. The functional traits considered were the scores obtained in the dressage and maneability trials of working equitation (WE, about 1500 records by 200 horses), and classical dressage (12,131 records by 759 horses). The heritability (h 2) estimates for all partial morphological scores ranged between 0.12 and 0.18, except for legs (0.07). The h 2 for final score, height at withers and gaits was 0.18, 0.61 and 0.17, respectively, while for WE dressage trial and classical dressage it was 0.32 and for WE maneability trial it was 0.18. The genetic correlations (r G ) of final score with the different partial scores were generally high (0.56–0.95), while among partial components of morphology they were positive but widely different (0.08–0.77). With the exception of legs, r G between morphology/gaits and functional traits were positive, with a stronger relationship between morphological traits and performance in WE dressage trial (r G between 0.36 and 0.56) when compared with performance in maneability trial or classical dressage. Height at withers had a r G of 0.40 with performance in classical dressage, but lower r G (0.06 and −0.10) with WE trials. Final score and overall impression had moderate to strong genetic relationships with functional traits, especially with WE dressage trial, while gaits had a strong r G with performance in all the disciplines (0.60–0.72). Indirect selection for morphology/gaits to improve functionality was assessed, by selecting for final score or a combined index of partial scores. Compared to direct selection for functionality, selection for final score or an index combining partial morphological scores would be less effective, resulting in accuracies of, respectively, 0.28 and 0.37 for WE dressage trial, 0.14 and 0.38 for WE maneability trial and 0.22 and 0.39 for classical dressage. Thus, an index combining all partial morphological scores would be better than selection for overall final score, but its relative efficiency compared to direct selection would be about 0.7 in WE dressage trial and classical dressage, and 0.9 in WE maneability trial. Lusitano horses maintain considerable levels of genetic variability, and selection for both morphology and functionality should be effective. The favorable genetic relationships existing between morphology and performance indicate that morphology/gaits traits can play an important role in a two-stage selection program, contributing to enhance selection response when the genetic improvement of working equitation or classical dressage is intended.


      PubDate: 2014-04-27T22:53:02Z
       
 
 
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