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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  [2575 journals]   [SJR: 0.728]   [H-I: 63]
  • Effects of cross-fostering within 24h after birth on pre-weaning
           behaviour, growth performance and survival rate of biological and adopted
           piglets
    • Abstract: Publication date: December 2012
      Source:Livestock Science, Volume 150, Issues 1–3
      Author(s): G. Heim , A.P.G. Mellagi , T. Bierhals , L.P. de Souza , H.C.C. de Fries , P. Piuco , E. Seidel , M.L. Bernardi , I. Wentz , F.P. Bortolozzo
      Cross-fostering is the transference of piglets to equalise litter size according to the birth weight. In many commercial farms piglets are usually grouped in litters with 100% adopted piglets. The aim of the experiment was to assess the behaviour of piglets during the suckling period as well as to assess their performance and mortality rate up to weaning in litters with different composition in terms of adopted and biological piglets. Three treatments were studied: 100B (100% biological piglets, n=13), 50B50A (50% biological piglets and 50% adopted piglets, n=13) and 100A (100% adopted piglets, n=13). All litters were standardised to eleven piglets on average within 20.1±0.4h (14.3–24.7h) of birth. The behaviour of piglets was recorded during four consecutive sucklings for four days (days 1, 2, 4 and 6 after farrowing, considering day 1 as the cross-fostering day). The observations were performed at two time periods: TP1 (from release of piglets out of creep box until milk letdown) and TP2 (from the end of milk letdown up to 15min later). Piglets were weighed at days 1, 4, 7, 10, 13 and 16. There were no differences (P>0.05) among the treatments in the following behavioural variables: percentage of missed nursing episodes; number of fights for teats and percentage of piglets involved in fights at TP1; percentage of piglets vocalising at TP1 and at TP2; number of fights per piglet elsewhere in the cage and percentage of piglets involved in these fights; number of instances of playful behaviour per piglet and percentage of piglets involved in it. At TP2 of day 1, 100B piglets displayed a lower number (P<0.05) of fights for teat (0.9 vs. 1.6 vs. 1.4 for 100B, 100A and 50B50A, respectively) and tended to have a lower percentage (P<0.07) of piglets involved in these fights than 100A (49.6%, 67.2% and 64.9% for 100B, 100A and 50B50A, respectively). Nutritive nursing episodes (overall medians of 4.0, 3.0, 4.0 and 4.0 for days 1, 2, 4 and 6, respectively), survival rate (overall 97.2%) and average weight of piglets (1983g, 2650g, 3411g, 4207g and 5047g for days 4, 7, 10, 13 and 16, respectively) were similar (P>0.05) among treatments. Cross-fostering performed on average at 20h after birth has no adverse effects on survival and growth performance of adopted piglets.


      PubDate: 2014-12-18T17:34:52Z
       
  • Differentially transcribed genes in skeletal muscle of lambs
    • Abstract: Publication date: December 2012
      Source:Livestock Science, Volume 150, Issues 1–3
      Author(s): Ana Maria Bezerra Oliveira Lôbo , Simone Eliza Faccioni Guimarães , Samuel Rezende Paiva , Fernando Flores Cardoso , Fabyano Fonseca Silva , Gerardo Alves Fernandes Júnior , Raimundo Nonato Braga Lôbo
      The objective of this study was to compare gene transcription profiles in Longissimus dorsi muscle of the following four hair sheep genetic groups, Morada Nova (MO), Brazilian Somali (SO), Santa Inês (SI) and ½Dorper×½Morada Nova (F1). These groups all display different postnatal muscle growth. The transcriptomes of the skeletal muscle of the lambs (at 200 days of age) were profiled by using oligonucleotide microarrays and reverse transcription-quantitative real-time PCR (RT-qPCR). The microarray experiment identified 262 transcripts that were differentially expressed when transcription levels were compared between the different breeds. A total of 23 transcripts among which those involved in skeletal muscle development (MyoD1 and IGFBP4), lipogenesis and adipogenesis (C/EBPδ, PPARγ and PGDS) were differentially expressed in at least in one comparison. Clustering analysis showed that there is greater similarity in gene expression between the MO and SI breeds and between F1 and SO genetic groups. The SO breed has the most distinct expression pattern. The RT-qPCR results confirmed the findings from the microarray study. A positive correlation was observed between the expression of MyoD1 and the cold carcass yield. The negative correlations between the weight and yield of cold carcass with the expression of C/EBPδ mean that the selection for adipogenesis could lead to a lower carcass weight. The GLUT3 and PYGL gene transcripts were negatively correlated with fat thickness, but ATP5G1 was positively correlated with this trait. Interestingly, many genes negatively correlated with PUFA were positively correlated with cold carcass yield. In conclusion, the present work demonstrated that there are breed-specific expression patterns in Brazilian hair sheep genetic groups. The differences in gene expression among genetic groups were consistent with their phenotypic differences. The positive correlation of the MyoD1 expression with the cold carcass yield suggests that this gene is important for tissue growth in sheep. The positive correlation of the C/EBPδ expression with PUFA provides an opportunity to select for lipid deposition in meat animals.


      PubDate: 2014-12-18T17:34:52Z
       
  • Evaluation of equations to predict body composition in Nellore bulls
    • Abstract: Publication date: January 2013
      Source:Livestock Science, Volume 151, Issue 1
      Author(s): L.F. Costa e Silva , S.C. Valadares Filho , E. Detmann , M.I. Marcondes , P.P. Rotta , L.F. Prados , D. Zanetti
      The equations developed by Hankins and Howe (1946, HH), Marcondes et al. (2010, M10), Marcondes et al. (in press, M11) and Valadares Filho et al. (2006, V6) were evaluated to predict the body composition from the 9–10–11th rib cut in Nellore bulls. The evaluated equations estimated the physical and the carcass chemical composition, the empty body chemical composition and the noncarcass chemical composition. Thirty-seven Nellore bulls (14±1 months old initially) with shrunk body weight of 259±24.9kg were used in this experiment. The bulls were randomly divided into three groups: five bulls to the reference group, four bulls were fed at maintenance level and twenty-eight bulls were fed ad libitum. The bulls fed ad libitum were separated into four groups, one of which was slaughtered every 42 days. The diet was composed of corn silage and concentrate (55:45). After slaughter, the 9–10–11th rib cut was dissected into muscle, fat and bone fractions. The remaining carcass was similarly dissected. The others parameters that were evaluated as partial predictors included the empty body weight, the dressing percentage, the visceral fat percentage, the organ and viscera percentage and the composition of the noncarcass components. The values estimated with prediction equations were compared to the observed values. The equations obtained by M11 predicted correctly the carcass physical composition. However, the muscle and fat tissues were under- and overestimated, respectively, by HH. Some constituents of the noncarcass components can be predicted from equations developed by M10. The equations obtained by M10 predicted correctly the carcass and empty body chemical composition. The carcass water was underestimated by HH. The equations by V6 did not predict the carcass or empty body chemical composition. The carcass physical and chemical composition and empty body chemical composition can be predicted from the composition of 9–10–11th rib cut by equations obtained by Marcondes et al. (2010, in press) while the composition of these components cannot be predicted by Hankins and Howe (1946) and Valadares Filho et al. (2006) in Nellore bulls.


      PubDate: 2014-12-18T17:34:52Z
       
  • Effect of methionine supplementation on mitochondrial genes expression in
           the breast muscle and liver of broilers
    • Abstract: Publication date: February 2013
      Source:Livestock Science, Volume 151, Issues 2–3
      Author(s): Ana Paula Del Vesco , Eliane Gasparino , Adhemar Rodrigues Oliveira Neto , Robson Marcelo Rossi , Maria Amélia Menck Soares , Stefânia Caroline Claudino da Silva
      This study aimed at evaluating the expression of the mRNA of avian uncoupling protein (avUCP), of adenine nucleotide translocase (ANT), and of cytochrome c oxidase subunit III (COX III), as well as the performance of broilers fed diets containing two sources and two levels of industrial methionine. Broilers between 22 and 42 days of age were distributed into five treatments (basal diet, supplementation of 0.08% dl-methionine, 0.24% of dl-methionine, 0.11% of MHA-FA and 0.33% of MHA-FA). At the end of the experimental period, birds were sacrificed by neck dislocation and their liver and breast muscle were collected for total RNA extraction. The cDNA was amplified using primers specific for the target genes, and expression was analyzed using the real-time polymerase reaction (qRT-PCR). Methionine supplementation promoted better performance, with the second level (0.24%) of dl-methionine promoting the best results for weight gain. The mRNA avUCP concentration was significantly lower in the muscle of birds fed methionine-supplemented diets, independently of source or level. The highest mRNA avUCP expression was obtained with the basal diet, which also resulted in the worst feed efficiency. The expression of mRNA avUCP in the liver and of mRNA COX III and mRNA ANT in the liver and in the muscle was not influenced by methionine supplementation. Methionine supplementation promotes better broiler performance, and the most efficient birds were fed second level of supplementation of both sources, part of these results may be due to the lower expression of avUCP mRNA in the muscle, which was also lower in birds fed diets with higher amounts of methionine.


      PubDate: 2014-12-18T17:34:52Z
       
  • Genetic parameters for test-day milk yield, 305-day milk yield, and
           lactation length in Guzerat cows
    • Abstract: Publication date: April 2013
      Source:Livestock Science, Volume 152, Issues 2–3
      Author(s): D.J.A. Santos , M.G.C.D. Peixoto , R.R.A. Borquis , R.S. Verneque , J.C.C. Panetto , H. Tonhati
      Milk production in tropical environments requires the use of crossbreeding systems including breeds well adapted to harsh conditions, but with lower productivities when compared to specialized breeds. Besides the genetic improvement for milk production, lactation lengths also need to be studied for most of these breeds. Accordingly, genetic parameters were estimated for 305-day cumulative milk yield (MY305), test-day milk yield (TDMY), and lactation length (LL) using information from the first lactations of 2816 Guzerat cows selected for milk production in 28 herds in Brazil. Contemporary groups were defined as herd, year and season of the test for TDMY, and as herd, year and season of calving for MY305 and LL. Variance components were estimated with the restricted maximum likelihood method under a multi-trait animal model. Heritabilities estimated for TDMY ranged from 0.16 to 0.24, and were 0.24 and 0.12 for MY305 and LL, respectively. Genetic correlations were high and positive, ranging from 0.51 to 0.99 among TDMY records, from 0.81 to 0.98 between each TDMY and MY305, and from 0.71 to 0.94 between each TDMY and LL. Genetic parameters obtained in this study indicated the possibility of using test-day records for the prediction of breeding values for milk yield in this population of the Guzerat breed. The use of TDMY as selection criteria would result in indirect gains in MY305 and LL. However, the highest response to selection for MY305 would be obtained by direct selection for this trait.


      PubDate: 2014-12-18T17:34:52Z
       
  • Intestinal IgG uptake by small intestine of goat kid fed goat or
           lyophilized bovine colostrum
    • Abstract: Publication date: April 2012
      Source:Livestock Science, Volume 144, Issue 3
      Author(s): W.M. Nordi , D.B. Moretti , A.L. Lima , P. Pauletti , I. Susin , R. Machado-Neto
      The immunoglobulin G (IgG) uptake and enterocyte nucleus position in the villous were studied in newborn goat kids fed goat or lyophilized bovine colostrum. Two groups of 15 newborn goat kids, each received 5% of body weight of goat colostrum (GC) or lyophilized bovine colostrum (LBC) containing 55mg/mL of immunoglobulin G (IgG) at 0, 7 and 14h of life. Three animals were sampled just after birth, receiving no colostrum intake, to be used as control. Samples of duodenum, medium jejunum and ileum were collected at 0, 18, 36 and 96h of life. IgG vacuoles were not observed in the duodenum throughout the experiment regardless of all the experimental time points. In this segment, at 0, 18 and 36h of life, nuclei were found in the apical, medial and basal positions in the enterocytes, and localized in the upper, medial and lower parts in the villous, respectively. At 96h, a basal nuclei position was observed in the enterocytes, throughout the villous. In jejunum, IgG vacuoles were distributed along the villous at 18 and 36h. In this segment at 0h the nuclei were positioned predominantly apically in the enterocytes, throughout the villous. At 18 and 36h, no consistent nuclei pattern was verified; however at 96h, the nuclei were positioned basally in the enterocytes, throughout the jejunal villous. In the ileum at 0, 18 and 36h, a great number of vacuoles without IgG were verified in the medial–apical part of the villous. In this segment, at 0h of life and 96h of life, the predominance of basal nuclei was observed. Nuclei were positioned in medial–apically part of the ileal enterocytes in the upper part of the villous at 18 and 36h. It was found that the jejunal epithelium was the most important segment related to absorption process. The IgG absorption and nucleus position in the newborn goats were dependent on the small intestine segments and experimental time points, regardless of the colostrum source, GC or LCB. Considering the IgG uptake mechanism observed in the present study, the lyophilized bovine colostrum might be used instead of goat colostrum.


      PubDate: 2014-12-18T17:34:52Z
       
  • Feed efficiency and its correlations with carcass traits measured by
           ultrasound in Nellore bulls
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): M.H.A. Santana , P. Rossi Jr. , R. Almeida , D.C. Cucco
      Forty-six Nellore bulls were individually fed for 84days and evaluated for residual feed intake (RFI) and feed conversion ratio (FCR) with the objective to correlate RFI1 (usual), RFI2 (adjusted for final rump fat thickness) and FCR with carcass composition traits measured by ultrasound and to verify differences between RFI groups (classified by standard deviation) in performance and carcass traits. Carcass traits were evaluated by ultrasound at the beginning and at the end of the test and the gain over the test period was calculated for ribeye area (REA), backfat thickness on the 12–13th ribs (BFT) and rump fat thickness on the Biceps femoris muscle (RFT). The RFI1 was positively correlated (P<0.05) with the final RFT (r=0.34) and with the gain in RFT (r=0.36) and also there were differences (P<0.05) in these traits and also in dry matter intake (DMI) between groups, in which the most efficient animals had lower values of DMI, final RFT, and gain in RFT. For the RFI2, there were no differences (P>0.05) between groups and neither were there significant correlations between those with the carcass traits, only for FCR, feed efficiency and DMI. FCR was correlated with the gain in REA and BFT (r=−0.43 and r=−0.31, respectively) and with the initial BFT (r=0.31). The positive correlation between residual feed intake and subcutaneous fat of Nellore bulls' may cause some concern, because with the selection of more efficient individuals (with negative RFI), carcasses which are too lean will be produced. Adjustments in the estimation of RFI including carcass traits may override this undesirable effect.


      PubDate: 2014-12-18T17:34:52Z
       
  • Lyophilized bovine colostrum as a source of immunoglobulins and
           insulin-like growth factor for newborn goat kids
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): Débora Botéquio Moretti , Wiolene Montanari Nordi , Anali Linhares Lima , Patrícia Pauletti , Ivanete Susin , Raul Machado-Neto
      The objective of this study was to evaluate lyophilized bovine colostrum as an alternative source of passive immunity and insulin like growth factor I (IGF-I) for goat kids, considering newborns consuming non-maternal colostrum. Twenty-nine male newborns received 5% of body weight of lyophilized bovine (LBC) or goat colostrum (GC), both with 55mg/mL of IgG, at 0, 7 and 14h of life. Blood samples were collected at 0, 7, 14, 18, 24, 36, 48, 72 and 96h of life to determine serum IgG, total protein (TP), IGF-I and apparent efficiency of IgG absorption at 7, 14, 18 and 24h (AEA 7hr , AEA 14hr , AEA 18hr , AEA total , respectively). In LBC, the values of serum IgG at 14, 18, 24 and 48h (13.1, 13.4, 14.1 and 14.6mg/mL, respectively) were higher than the values at 0 and 7h (0.04 and 6.9mg/mL, respectively). In GC, the serum IgG at 18h (9.3mg/mL) was higher than the value at 7h (5.5mg/mL). AEA 7hr and AEA 14hr in LBC were the same (19.2 and 18.5%, respectively, P>0.05) and the values of AEA 18hr and AEA total , 9.3 and 9.5%, respectively, were equal and smaller than AEA 7hr and AEA 14hr . In GC, AEA 7hr , 20.8%, was higher than AEA 14hr , 16.1% (P<0.05) and AEA 18hr and AEA total , 9.2 and 8.0%, respectively, were equal and smaller than AEA 7hr and AEA 14hr. The serum TP and IGF-I were not affected by colostrum feeding. Considering the variables study in the present work, lyophilized bovine colostrum constitutes a promising alternative substitute to goat colostrum in newborn goat kids, since the supply of immunoglobulins and IGF-I was suitable for the kids.


      PubDate: 2014-12-18T17:34:52Z
       
  • Effects of propiogenic ingredients on serum concentration of insulin and
           progesterone in non-lactating cows
    • Abstract: Publication date: May 2013
      Source:Livestock Science, Volume 153, Issues 1–3
      Author(s): T. Leiva , R.F. Cooke , A.C. Aboin , H.F. Soares , M. Barbosa , A.M.L. Madureira , M.A.F. Borges , J.L.M. Vasconcelos
      Three experiments evaluated serum insulin and progesterone (P4) concentrations in grazing Gir×Holstein cows supplemented with monensin (MON) or propylene glycol (PPG; 2.5mL/kg of live weight0.75 per drench). Cows were non-lactating, ovariectomized, and received an intravaginal drug-releasing device containing 1.9g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 15 cows received, in a crossover design containing 2 periods of 21d, 0.1kg/d of corn in addition to 2g/d of kaolin (CON) or 0.2g/d of MON. Blood samples were collected on d 13 and 20 of each period. Cows receiving CON had greater (P<0.05) serum insulin concentrations compared with MON prior to and 6h after feeding. However, MON cows had greater (P=0.01) serum P4 concentrations compared with CON 18h after feeding. In experiment 2, 15 cows received, in a replicated crossover design containing 2 periods of 24h, a single drench of PPG or water (WT). Cows receiving PPG had greater (P<0.01) serum insulin concentrations compared with WT from 0.5 to 3h after drench. However, PPG cows had reduced (P<0.05) serum P4 concentrations compared with WT at 1 and 2h after drench. In experiment 3, 13 cows received, in a replicated 3×3 Latin square design containing 3 periods of 24h, 3 PPG drenches administered 1h apart (PPG3x), 3 WT drenches administered 1h apart, or 1 PPG drench+2 WT drenches administered 1h apart (PPG1x). Serum insulin concentrations increased proportionally to PPG dosage (treatment×hour; P<0.01). However, mean serum P4 concentration was greater (P<0.01) in WT cows compared with PPG1x and PPG3x, but similar (P=0.25) between PPG1x and PPG3x cows. In conclusion, feeding propiogenic ingredients to grazing cows failed to substantially increase serum P4 concentrations.


      PubDate: 2014-12-18T17:34:52Z
       
  • Effects of maternal nutrition on development of gastrointestinal tract of
           bovine fetus at different stages of gestation
    • Abstract: Publication date: May 2013
      Source:Livestock Science, Volume 153, Issues 1–3
      Author(s): M.S. Duarte , M.P. Gionbelli , P.V.R. Paulino , N.V.L. Serão , T.S. Martins , P.I.S. Tótaro , C.A. Neves , S.C. Valadares Filho , M.V. Dodson , M. Zhu , M. Du
      This study was developed aiming to evaluate the effects of maternal feed-restriction on development of gastrointestinal tract (GIT) of bovine fetus at different gestational stages. Feed-restricted cows were fed 1.2 times the maintenance level while the control group was fed ad libitum. Pregnant cows were slaughtered at 136, 189, 239, and 269 days of gestation and gastrointestinal tracts of the fetuses were evaluated. No effects of maternal nutrition on body weight (P=0.17) and body length (P=0.13) of the fetuses were observed. No major effects of feed restriction on GIT mass of the fetuses were observed (P=0.51). However, the weight of small intestine per unit of body weight was 11.24% greater (P=0.04) in fetuses from restricted dams. Additionally, the length of small intestine and its villi were 12.93% and 16.44% respectively greater (P<.001) in fetuses from restricted dams compared to those from non-restricted dams. These data indicates that maternal feed-restriction does not affect the development of most of fetal gastrointestinal parts besides small intestine which in turn increases its surface area as a response of maternal feed restriction.


      PubDate: 2014-12-18T17:34:52Z
       
  • Interaction of dietary vitamin D3 and sunlight exposure on B. indicus
           cattle: Animal performance, carcass traits, and meat quality
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): A.R. Lobo-Jr. , E.F. Delgado , G.B. Mourão , A.C.M.S. Pedreira , A. Berndt , J.J.A.A. Demarchi
      Attempts to improve beef tenderness through supplementation with dietary vitamin D3 have been challenged by null results and negative impacts on animal performance and carcass traits. Because vitamin D3 is also synthesised by the animal via ultraviolet radiation from sunlight, the effectiveness of supplementation with dietary vitamin D3 may be modulated by the degree of exposure of the animal to sunlight. Hence, this work aimed to verify whether dietary vitamin D3 modifies meat quality without negatively affecting animal performance and carcass traits in B. indicus beef cattle that were either exposed to or protected from natural sunlight. Forty-two (411±38kg) Nellore-type castrated males were fed a high-concentrate diet for 45days after assignment to a treatment group. The treatments comprised combinations of three levels of vitamin D3 [ViTD — none (V0) or 2×106 IU of vitamin D3 administered for either 2 (V2) or 8 (V8) consecutive days pre-slaughter] and two shading conditions (SHADE — unshaded or shaded). The post-mortem (pm) measurements were taken in the Longissimus thoracis et lumborum muscle. The animal performance and carcass traits were unaffected by ViTD or SHADE. The V2 treatment increased the Myofibrillar Fragmentation Index in shaded animals compared to unshaded ones. Animals under shade had higher muscle calcium concentration. There was no effect of either ViTD or SHADE on the shear force. The L* values were higher at 24h pm than at 0 and 1h pm, with no differences among the animals in the ViTD or SHADE groups. Higher a* values were observed among animals in the V8 group than in the V0 group, and higher b* values were observed among animals in the V8 group than in the V2 or V0 groups, which were not different. In conclusion, ViTD and SHADE did not affect animal performance, carcass traits or shear force, whereas animals receiving a lower ViTD dosage and SHADE exhibited altered myofibrillar fragmentation. ViTD affected the colour parameters, and changes in the lightness of the beef related to the time pm were found in meat from animals under SHADE.


      PubDate: 2014-12-18T17:34:52Z
       
  • Genetic parameters of body weight and egg traits in meat-type quail
    • Abstract: Publication date: May 2013
      Source:Livestock Science, Volume 153, Issues 1–3
      Author(s): Luciano P. Silva , Jeferson C. Ribeiro , Aline C. Crispim , Felipe G. Silva , Cristina M. Bonafé , Fabyano F. Silva , Robledo A. Torres
      Data from two quail strains, UFV1 and UFV 2, measured weekly from hatch to sixth week in a total of seven live body weight traits were used aiming to estimate genetic correlations and heritabilities. After females were evaluated they were monitored in their egg-laying phase, in which the total egg number, the average weight of the eggs and the average specific gravity of eggs were measured. Multi-trait analysis was performed with the ten traits measured for estimation of heritabilities, genetic and residual correlations. For body weight traits, heritabilities varying from 0.25 to 0.53 for UFV1 and from 0.27 to 0.53 for UFV2 were estimated; genetic correlations increased as the interval between records was reduced. For egg number, the heritability estimate was of low magnitude (0.05 and 0.04), whereas for average egg weight (0.41 and 0.39) and egg specific gravity (0.31 and 0.18), they were of moderate magnitude for UFV1 and UFV2, respectively. The genetic correlations between body weights and egg number were negative in UFV1 and positive in UFV2; for average egg weight, they were positive, and for specific gravity, they were negative for both strains. It can be concluded, then, that selection based on body weight in the growth phase of meat quail must be done preferably at early ages such as weight at the third or fourth week of life, once they are positively correlated with weight at slaughter age and have few effects on the production and quality of eggs.


      PubDate: 2014-12-18T17:34:52Z
       
  • Effects of bovine somatotropin injection on serum concentrations of
           progesterone in non-lactating dairy cows
    • Abstract: Publication date: June 2013
      Source:Livestock Science, Volume 154, Issues 1–3
      Author(s): A.C. Aboin , R.F. Cooke , F.V.R. Vieira , T. Leiva , J.L.M. Vasconcelos
      The objective of this experiment was to evaluate the effects of bovine somatotropin administration on serum concentrations of glucose, insulin, NEFA, IGF-I, and progesterone (P4) in ovariectomized non-lactating dairy cows receiving exogenous P4, as a model to estimate treatment effects on hepatic P4 degradation. Ten non-lactating, non-pregnant, and ovariectomized Gir×Holstein cows were assigned to the experiment (d −14 to 27). On d 0, cows were ranked by BW and BCS, and randomly assigned to one of two treatments: (1) bovine somatotropin (BST; n=5) or (2) saline control (control; n=5). Cows assigned to the BST treatment were administered s.c. injections containing 500mg of sometribove zinc on d 0, 9, and 18 of the experiment, whereas control cows concurrently received a 10-mL s.c. injection of 0.9% saline. On d −2, cows were inserted with an intravaginal releasing device containing 1.9g of P4, which remained in the cows until the end the experiment (d 27). Cow BW and BCS were assessed on d −14, 0, and 27. Blood samples were collected daily from d 0 to d 27, at 0 (immediately before), 1, and 2h relative to concentrate feeding for determination of serum glucose, insulin, NEFA, P4, and IGF-I concentrations. Concentrations of glucose, NEFA, and insulin obtained prior to feeding (0h) were used to determine pre-prandial revised quantitative insulin sensitivity check index (RQUICKI). No treatment effects were detected for BW (P=0.72) and BCS change (P=0.79) during the experiment. Beginning on d 2 of the experiment, BST cows had greater (P≤0.01) serum IGF-I concentrations compared with control cohorts (treatment×day interaction; P<0.01). Cows receiving BST had greater (P≤0.05) insulin concentrations compared with control cohorts from d 8 to d 11, d 16 and 17, as well as from d 19 to d 21 of the experiment (treatment×day interaction; P<0.01). Cows receiving BST had greater (P≤0.01) mean glucose and NEFA concentrations, as well as reduced (P<0.01) mean RQUICKI during the experiment compared with control cohorts. No treatment effects, however, were detected (P=0.73) for serum P4 concentrations. In conclusion, results from this experiment indicate that hepatic P4 catabolism is not directly regulated by circulating IGF-I, whereas BST administration decreases insulin sensitivity in non-lactating dairy cows in adequate nutritional status.


      PubDate: 2014-12-18T17:34:52Z
       
  • Female fertility in a Guzerat dairy subpopulation: Heterogeneity of
           variance components for calving intervals
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): J.C.C. Panetto , J.E. Val , C.R. Marcondes , M.G.C.D. Peixoto , R.S. Verneque , J.B.S. Ferraz , B.L. Golden
      The objectives of the present study were to determine if variance components of calving intervals varied with age at calving and if considering calving intervals as a longitudinal trait would be a useful approach for fertility analysis of Zebu dairy herds. With these purposes, calving records from females born from 1940 to 2006 in a Guzerat dairy subpopulation in Brazil were analyzed. The fixed effects of contemporary groups, formed by year and farm at birth or at calving, and the regressions of age at calving, equivalent inbreeding coefficient and day of the year on the studied traits were considered in the statistical models. In one approach, calving intervals (CI) were analyzed as a single trait, by fitting a statistical model on which both animal and permanent environment effects were adjusted for the effect of age at calving by random regression. In a second approach, a four-trait analysis was conducted, including age at first calving (AFC) and three different female categories for the calving intervals: first calving females; young females (less than 80months old, but not first calving); or mature females (80months old or more). Finally, a two-trait analysis was performed, also including AFC and CI, but calving intervals were regarded as a single trait in a repeatability model. Additionally, the ranking of sires was compared among approaches. Calving intervals decreased with age until females were about 80months old, remaining nearly constant after that age. A quasi-linear increase of 11.5days on the calving intervals was observed for each 10% increase in the female's equivalent inbreeding coefficient. The heritability of AFC was 0.37. For CI, the genetic-phenotypic variance ratios ranged from 0.064 to 0.141, depending on the approach and on ages at calving. Differences among genetic variance components for calving intervals were observed along the animal's lifetime. Those differences confirmed the longitudinal aspect of that trait, indicating the importance of such consideration when accessing fertility of Zebu dairy females, especially in situations where the available information relies on their calving intervals. Spearman rank correlations among approaches ranged from 0.90 to 0.95, and changes observed in the ranking of sires suggested that the genetic progress of the population could be affected by the approach chosen for the analysis of calving intervals.


      PubDate: 2014-12-18T17:34:52Z
       
  • Distinct incubation for homologous in vitro spermatozoa binding on swine
           oocytes subjected to different storage conditions
    • Abstract: Publication date: June 2013
      Source:Livestock Science, Volume 154, Issues 1–3
      Author(s): C.D. Corcini , A.S. Varela Junior , E.C.S. Santos , S.M.M. Gheller , V.M. Danieli , R.M.R. Brizolara , B.S. Elert , A.D. Vieira , D.C. Bongalhardo , T. Lucia Jr.
      The sperm in vitro binding assay in homologous oocytes can be used to estimate the boar fertility potential, but its usefulness may be limited by laboratorial structure and oocytes availability. This study aimed at determining the effect of distinct methods of oocytes conditioning and incubation media for the in vitro penetration (IVP) test. Oocytes used in the IVP test were: fresh and conditioned in PBS (T1); cooled and conditioned in PBS at 5°C for 48h (T2); or stored in ovaries frozen at −20°C (T3). For each treatment, two incubation media were tested at 39°C for 6h: modified TRIS buffer medium (mTBM); or Beltsville Thawing Solution (BTS) extender. The responses of interest were: IVP and polyspermy rates; and the number of penetrating spermatozoa per oocyte. All responses observed with incubation in BTS were inferior to those observed with incubation in mTBM (P<0.0001). When incubation was done in mTBM, none of the responses differed across treatments (P>0.05). However, when incubation was in BTS, all the three responses were superior for T1 than for T2 and T3 (P<0.05). Thus, the IVP test may be conducted with ovaries either cooled or recovered from frozen ovaries with results similar to those observed with fresh oocytes, if incubation is done in mTBM.


      PubDate: 2014-12-18T17:34:52Z
       
  • Rice oil as a soybean oil replacement in weanling pig diets
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): Maicon Sbardella , Bernardo Berenchtein , Carla de Andrade , Danilo do Prado Perina , Vivian Vezzoni de Almeida , Valdomiro Shigueru Miyada
      The motivation for including oils in the diets of weanling pigs is to increase dietary energy density to meet the pigs' energy requirements. The purpose of this study was to determine the digestible and metabolizable energy values of semi-refined rice oil (RO) and refined soybean oil (SO) for weanling pigs (Experiment 1), as well as to evaluate how replacing SO with RO in weanling pig diets affects performance, intestinal histology, organ morphometry and the occurrence of diarrhea (Experiment 2). In Experiment 1, 21 barrows, averaging 19.63±0.37kg body weight (BW), were used in a randomized complete block design experiment, with seven replications per treatment and one pig per experimental unit (metabolism cage). The treatments consisted of a reference diet and two test diets. The test diets were obtained by using 90% of the reference diet and 10% of RO or SO. The experimental period consisted of a 7days adaptation period, followed by a 5days collection period of feces and urine. The values of the apparent digestible energy, apparent metabolizable energy and N-corrected apparent metabolizable energy of the oils were, respectively, 26.24, 25.78 and 26.01MJkg−1 for RO and 31.74, 31.35 and 31.51MJkg−1 for SO. In Experiment 2, 120 weaned pigs, castrated males and females, averaging 6.74±0.42kg BW, were used in a randomized complete block design experiment, with eight replications per treatment and three pigs per experimental unit (pen) to evaluate the effects of five replacement levels of SO with RO in isonutritive weanling pig diets. The treatments were as follows: 4:0—basal diet with 4% of SO; 3:1—basal diet with 3% of SO and 1% of RO; 2:2—basal diet with 2% of SO and 2% of RO; 1:3—basal diet with 1% of SO and 3% of RO; and 0:4—basal diet with 4% of RO. No effects of the replacement levels were observed in the weanling pigs' performance, organ morphometry or in their occurrence of diarrhea. However, a quadratic effect on the villus width and a cubic effect on the villus height:crypt depth ratio were observed in the duodenum. Therefore, if the determined values of energy are used in the feed formulation, refined soybean oil can be replaced with semi-refined rice oil in weanling pig diets without affecting their growth performance.


      PubDate: 2014-12-18T17:34:52Z
       
  • Assessment of field fertility and several in vitro sperm characteristics
           following the use of different Angus sires in a timed-AI program with
           suckled Nelore cows
    • Abstract: Publication date: June 2012
      Source:Livestock Science, Volume 146, Issue 1
      Author(s): Letícia Zoccolaro Oliveira , Rubens Paes de Arruda , André Furugen Cesar de Andrade , Eneiva Carla Carvalho Celeghini , Ricarda Maria dos Santos , Marcelo Emílio Beletti , Rogério Fonseca Guimarães Peres , Clara Slade Oliveira , Vera Fernanda Martins Hossepian de Lima
      In order to provide information that may help researchers to understand the main cause(s) of differences in bull fertility frequently observed in field trials, this study aimed to investigate conception rates as well as several in vitro sperm characteristics of different sires of unknown fertility utilized in a Timed-AI (TAI) program. Suckled Nelore cows submitted to the same TAI protocol were allocated into eight breeding groups of approximately 120 animals each. Frozen semen doses from three Angus bulls and three different batches from each bull were utilized. Approximately 100 doses from each batch were used in TAI. Sires, batches and AI technicians were equally distributed across breeding groups. Cows were examined for pregnancy diagnosis 40d after TAI. For in vitro sperm analyses, the same thawing procedure was repeated in the laboratory to mimic field conditions. The following in vitro sperm characteristics were assessed: computerized motility, thermal resistance, plasma and acrosomal membrane integrity, lipid peroxidation, morphology, morphometry and chromatin structure. No effect of breeding group, body condition score, AI technician and sire was observed. However, some significant differences among bulls were detected in laboratory analyses. Semen from sire presenting numerically lower (P>0.05) pregnancy/AI also presented lower (P<0.05) values in all sperm characteristics analyzed in thermal resistance test at 4h (Total Motility, Progressive Motility, Average Path Velocity, Straight-Line Velocity, Curvilinear Velocity, Amplitude of Lateral Head Displacement, Beat Cross Frequency, Straightness, Linearity, and Percentage of Rapidly Moving Cells), higher (P<0.05) Major and Total Defects in sperm morphological test, lower (P<0.05) Length, Ellipticity and Fourier parameter (Fourier 0) in sperm morphometric analysis as well as higher (P<0.05) chromatin heterogeneity. It was concluded that, although no bull effect was observed in the field experiment, the sire that presented numerically lower pregnancy/AI also presented lower semen quality according to the laboratory analyses performed.


      PubDate: 2014-12-18T17:34:52Z
       
  • Identification and expression levels of pig miRNAs in skeletal muscle
    • Abstract: Publication date: June 2013
      Source:Livestock Science, Volume 154, Issues 1–3
      Author(s): L.L. Verardo , C.S. Nascimento , F.F. Silva , E. Gasparino , E. Toriyama , A.R. Barbosa , I.V. Périssé , K.A. Costa , P.S. Lopes , S.E.F. Guimarães
      MicroRNAs are a class of naturally occurring non-coding RNAs. Typically they are ∼22 nucleotides long and suppress translation of their targets genes. Several laboratories have attempted to identify miRNAs from pig muscle and the bioinformatics strategies using ESTs have proved to be successful for this aim. In this study we report an in silico identification of ncRNA in pig EST libraries focusing on novel pig miRNAs and further investigated the differential expression of pigs miRNAs (known and novel) by quantitative real-time PCR during pre- and postnatal stage from Commercial and local breed Piau pigs skeletal muscle tissue. We identified two miRNAs not yet described in pigs: hsa-miR-1207-5p and hsa-miR-665. Besides, we found 288 target genes for hsa-miR-1207-5p and 214 for hsa-miR-665; from them, four are muscle specific genes. Through expression analyses, differences were found between pre- and postnatal stages and genetics groups. The findings of miRNAs and their muscle-specific targets in pigs will be helpful for understanding the function and processing of this RNA class in the future. Besides, the miRNAs differentially expressed between Commercial and Piau breeds suggest that they can be used to uncover phenotypic differences across different genetic groups.


      PubDate: 2014-12-18T17:34:52Z
       
  • Responses of Cobb×Cobb 500 slow feathering broilers to feeding
           programs with increasing amino acid densities
    • Abstract: Publication date: July 2012
      Source:Livestock Science, Volume 146, Issues 2–3
      Author(s): D. Taschetto , S.L. Vieira , R. Angel , A. Favero , R.A. Cruz
      An evaluation of the effects of feeding programs with three amino acid (AA) densities given to males and females from a fast growth broiler breed was conducted. A total of 1200 Cobb×Cobb 500 broilers were distributed across 6 treatments in a 2×3 factorial arrangement (Sex×AA Density) with 8 replications of 25 birds per pen. Maize–soybean meal, provided from 1 to 7, 8 to 21, 22 to 35 and 36 to 42d of age, was formulated without crude protein restriction maintaining minimum ratios between essential AA and Lysine (Lys) in a true digestible (dig) basis as follows: total sulfur AA, 0.75; threonine, 0.65, valine, 0.75 (from 1 to 21d) and 0.78 (from 22 to 42d). Experimental treatments were Low (L), Moderate (M) and High (H) AA density diets with M having dig Lys of 1.25, 1.19, 1.09 and 1.05% in the pre-starter to withdrawal phases, respectively. Diets L and H had reductions and increases of 12% dig Lys in relation to the Moderate diet. There were no effects of treatments on mortality (P>0.05) and males had an overall better performance than females (P<0.001). No interactions were observed between Sex×AA density, with the exception of feed intake (1–42 days) and abdominal fat, which were further reduced with males as AA density increased than with females (P<0.01). Body weight gain was affected by AA density (P=0.0308) with birds fed L diets being lighter than those fed H and M diets. Feed conversion ratio (FCR) was improved (P<0.05) as AA density increased. Carcass and breast meat percentages were higher for females (P<0.01) and percent breast yield was highest for the H diet and lowest for the L diet, whereas the M diet was in between. Abdominal fat was reduced with H diet (P<0.05) for males but not for females. The decision making process to change AA density in the diet towards a higher density AA diet will depend on the price of feed ingredients and broiler meat.


      PubDate: 2014-12-18T17:34:52Z
       
  • Influence of pig weight classification at cross-fostering on the
           performance of the primiparous sow and the adopted litter
    • Abstract: Publication date: July 2012
      Source:Livestock Science, Volume 146, Issues 2–3
      Author(s): T. Bierhals , D. Magnabosco , R.R. Ribeiro , J. Perin , R.A. da Cruz , M.L. Bernardi , I. Wentz , F.P. Bortolozzo
      The objective of this study was to evaluate the effects of piglet weight and variation in weight at cross-fostering on piglet and sow performance. Primiparous sows were allocated in three groups: group A (n=31)—litters with 14 Light piglets (1.0–1.2kg); group B (n=32)—litters with seven Light piglets and seven Intermediate piglets (1.4–1.6kg), and group C (n=31)—litters with 14 Intermediate piglets. Sows were weighed within 24h after farrowing and on days 7, 15 and 19 of lactation. Feed intake was measured daily during lactation. Subsequent weaning-to-oestrus interval (WOI), farrowing rate and litter size were evaluated. Piglets were weighed at cross-fostering and on days 7, 15 and 19 of lactation. Average daily feed intake, body reserves at farrowing and weaning, and body reserve losses of sows during lactation were similar among groups (P>0.10). Litter weight differed among groups, at all moments of evaluation, with the higher weight being observed in C group (P<0.05). Daily gain of litter was similar among groups (P>0.10). Survival rates up to 7 and 19 days were similar among groups (P>0.10). The percentage of sows showing oestrus until Day 7 after weaning was lower (P=0.03) and WOI tended to be higher (P=0.08) in group C compared to group A. Farrowing rate and second litter size were similar among groups (P>0.10). Sows with WOI>7 days had similar number of weaned piglets, feed intake and body reserve losses (P>0.10) to those with WOI≤7 days. However, long WOI sows had heavier litters at weaning and higher lactation efficiency than short WOI sows (P<0.05). In conclusion, WOI can be compromised in sows suckling litters composed entirely of Intermediate piglets compared to litters composed of Light piglets. This effect seems to be mediated by a greater intensity of sucking by heavier piglets rather than by greater body reserves mobilisation.


      PubDate: 2014-12-18T17:34:52Z
       
  • Intake and ruminal digestion determined using omasal and reticular digesta
           samples in cattle fed diets containing sugar cane in natura or ensiled
           sugar cane compared with maize silage
    • Abstract: Publication date: July 2013
      Source:Livestock Science, Volume 155, Issue 1
      Author(s): L.D.S. Mariz , S.C. Valadares Filho , E. Detmann , O.G. Pereira , L.G.R. Pereira , M.I. Marcondes , S.A. Santos , F.A.C. Villadiego , D. Zanetti , L.F. Prados , A.N. Nunes
      Sugar cane is widely used in an in natura forage in tropical countries, but the adoption of silage methods facilitates the preservation of its nutritional value and improves the logistics of its use. To explain differences in performance using alternative forages, it is important to conduct studies that evaluate the various digestion sites for the nutrients provided in diets. However, considering that the collection of omasal digesta is quite laborious and requires the use of a vacuum pump, reticular sampling has been suggested as a promising alternative. Thus, the objective of this study was to evaluate the intake and ruminal digestibility obtained from samples of digesta collected in the reticulum and omasum of cattle fed different diets. Five rumen-fistulated crossbred cattle with an average initial live weight of 336±16.6kg were used, being distributed in a 5×5 Latin square design. Five diets were evaluated, which contained 60% forage and 40% concentrate on dry matter basis using different forages: maize silage (CS); sugar cane in natura (SCIN); sugar cane silage (SCS0%); sugar cane silage treated with 0.4% calcium oxide (SCS0.4%) or 0.8% calcium oxide (SCS0.8%) on wet basis. The percentage of crude protein (CP) in all of the forages was corrected to 11% based on dry matter (DM) using a mixture of urea/ammonium sulfate (9:1). Six collections of reticular and omasal digesta were obtained over three days at 12h intervals. To calculate the flow of reticular and omasal nutrients, a double marker system was employed, using cobalt–EDTA and indigestible neutral detergent fiber (NDFi) as markers. The reticular and omasal digesta were similar (P>0.05) to estimate ruminal digestibility of DM, organic matter (OM), CP, neutral detergent fiber (NDF) and non-fiber carbohydrates (NFC). However, the ruminal digestibility of ether extract (EE) and the intestinal digestibility of CP and EE differed (P<0.05) between sampling sites. The results indicate that the omasal digesta is more suitable than the reticular digesta for measuring the ruminal digestion of diet components.


      PubDate: 2014-12-18T17:34:52Z
       
  • Management targets for maximising the short-term herbage intake rate of
           cattle grazing in Sorghum bicolor
    • Abstract: Publication date: May 2012
      Source:Livestock Science, Volume 145, Issues 1–3
      Author(s): L. Fonseca , J.C. Mezzalira , C. Bremm , R.S.A. Filho , H.L. Gonda , P. C.de F. Carvalho
      One of the variables in the structure of the sward with the most influence on the short-term herbage intake rate by grazing ruminants is the canopy height. The objective of this study was therefore to characterise the effect of the canopy height on short-term herbage intake rate using Sorghum bicolor cv BR 501. as a reference. Two experiments were conducted at Research Station of the Federal University of Rio Grande do Sul, Brazil, between December 2009 and April 2010. The treatments in experiment 1 were used to determine the influence of the pre-grazing canopy height on the short-term herbage intake and consisted of six canopy heights (30, 40, 50, 60, 70 and 80cm). The treatments in experiment 2 used the pre-grazing canopy height from experiment 1 that maximised the short-term herbage intake rate to evaluate the influence of the severity of grazing down (16, 33, 50, 67 and 84%) on the herbage intake. Both experiments used a completely randomised block design, with two replicates in experiment 1 and three replicates in experiment 2. Four heifers (24±2months and 306±56.7kg) were used in experiment 1. Three of these animals were used in experiment 2, which were then 26±2months and 339±45.5kg. The short-term herbage intake rate was measured by weighing the heifers pre- and post-grazing, corrected for insensible weight losses. The number of grazing jaw movements (biting and non-biting) was counted automatically using an IGER Behaviour Recorder. In both experiments, the sward measurements included the pre- and post-grazing canopy height, the pre-grazing herbage mass and the vertical distribution of morphological components. In experiment 2, the post-grazing herbage mass was also measured. The results showed that the grazing canopy height that maximised the short-term herbage intake rate was approximately 50cm. The grazing down protocol showed that the short-term herbage intake rate was constant until the depletion of 40% of the optimal pre-grazing canopy height. After this level of depletion, there was a marked reduction in the short-term herbage intake rate. The results show that the best target management height in a Sorghum cv. BR 501 pasture, allowing for high levels of the short-term herbage intake rate, is 50cm. With intermittent stocking, this level should be considered as the pre-grazing canopy height, and the level of herbage depletion should not exceed 40%.


      PubDate: 2014-12-18T17:34:52Z
       
  • Estimates of genetic parameters for carcass, growth and reproductive
           traits in Nellore cattle
    • Abstract: Publication date: July 2013
      Source:Livestock Science, Volume 155, Issue 1
      Author(s): S.L. Caetano , R.P. Savegnago , A.A. Boligon , S.B. Ramos , T.C.S. Chud , R.B. Lôbo , D.P. Munari
      The objective of this study was to estimate genetic parameters for female mature weight (FMW), age at first calving (AFC), weight gain from birth to 120 days (WG_B_120), from 210 to 365 days (WG_210_365), rib eye area (REA), back fat thickness (BF), rump fat (RF) and body weight at scanning date (BWS) using single and multiple-trait animal models by the REML method from Nellore cattle data. The estimates of heritability ranged from 0.163±0.011 for WG_210_365 to 0.309±0.028 for RF using the single-trait model and from 0.163±0.010 for WG_210_365 to 0.382±0.025 for BWS using the multiple-trait model. The estimates of genetic correlations ranged from −0.35±0.08 between AFC with BF to 0.69±0.04 between WG_B_120 with BWS. Selection for weights gains, REA, and BWS can improve FMW.


      PubDate: 2014-12-18T17:34:52Z
       
  • Localization patterns of steroid and luteinizing hormone receptors in the
           corpus luteum of Nelore (Bos taurus indicus) cows throughout the estrous
           cycle
    • Abstract: Publication date: August 2013
      Source:Livestock Science, Volume 155, Issues 2–3
      Author(s): Ian Martin , Marcela Marcondes Pinto Rodrigues , Caroline Junko Fujihara , Wolff Camargo Marques Filho , Eunice Oba , Renée Laufer-Amorim , João Carlos Pinheiro Ferreira
      The aim of the present study was to detect progesterone receptors (A and B isoforms), α and β estrogen receptors, luteinizing hormone receptors and aromatase cytochrome P450 enzymes in the corpus luteum of Nelore (Bos taurus indicus) cows using immunohistochemistry. The estrous cycles of 16 Nelore cows were synchronized, and luteal samples were collected via an incision into the vaginal vault. Samples were collected during specific days of the estrous cycle (days 6, 10, 15 and 18) and 24h after circulating progesterone dropped, after luteolysis had occurred. After each biopsy was taken, all animals were resynchronized so that each biopsy was performed during a different estrous cycle. Our results showed that the concentration of studied proteins vary throughout the bovine estrous cycle. The highest concentration of α and β estrogen receptors and the highest concentration of plasma progesterone were both observed on days 10 and 15 of the estrous cycle. The highest concentration of progesterone receptors was observed on days 6 and 10 of the estrous cycle, and the most intense immunostaining for cytochrome P450 aromatase enzymes was observed on day 10 of the estrous cycle. The highest score of cells with plasma membrane immunostaining for LH receptors was observed on day 15 of the estrous cycle. In conclusion, this study demonstrates the varying concentrations of specific proteins within the corpus luteum of Nelore cows during the estrous cycle. This finding suggests that these receptors and enzymes, and their interactions, are important in regulating luteal viability.


      PubDate: 2014-12-18T17:34:52Z
       
  • Soybean oil and crude protein levels for growing pigs kept under heat
           stress conditions
    • Abstract: Publication date: August 2012
      Source:Livestock Science, Volume 147, Issues 1–3
      Author(s): R.C. Wolp , N.E.B. Rodrigues , M.G. Zangeronimo , V.S. Cantarelli , E.T. Fialho , R. Philomeno , R.R. Alvarenga , L.F. Rocha
      This study was conducted to evaluate the effect of different levels of soybean oil (SO) and crude protein (CP) on performance and physiological and hormonal parameters of pigs in high-temperature environment. Eighty-four growing pigs with initial weight of 36.9±3.0kg were assigned to treatments in 2×3 factorial arrangement of dietary treatments plus 1 [two levels of CP, 18% and 15.5%, and three levels of SO, 1.5%, 3.0%, and 4.5% with all pigs kept at room temperature of 32°C, and an additional treatment (control) with 18% CP and 1.5% SO with pigs kept at 22°C], in a randomized block design with the block being the initial weight. In animals maintained in the high-temperature environment, there was no interaction between CP and SO levels in any of the variables evaluated. The addition of SO improved (P<0.05) the average daily gain (ADG) and feed:gain (F:G), but did not affect the average daily feed intake (ADFI). The reduction of CP resulted (P<0.05) in lower ADFI. Compared to animals kept at the comfort temperature, a high-temperature environment decreased the F:G (P<0.01) of animals fed diets with 18% CP and 1.5% SO. However, increasing the SO level resulted in similar values of F:G. For animals kept in a high-temperature environment, CP can be reduced in diets supplemented with amino acids only in diets with high SO levels. The high-temperature affected (P<0.01) body temperature and respiratory rate, but was not sufficient to change the levels of T3 and T4. It is concluded that SO levels should be increased in diets for animals kept in high-temperature environment, and the CP levels can be reduced only under these conditions, since supplemented with amino acids.


      PubDate: 2014-12-18T17:34:52Z
       
  • Intake and digestion by wethers fed a tropical grass-based diet
           supplemented with increasing levels of canola meal
    • Abstract: Publication date: August 2012
      Source:Livestock Science, Volume 147, Issues 1–3
      Author(s): F. Hentz , G.V. Kozloski , T. Orlandi , S.C. Ávila , P.S. Castagnino , C.M. Stefanello , Gabriel Faria Estivallet Pacheco
      Eight Polwarth×Texel wethers (31±3.8kg body weight (BW)), housed in metabolic cages and offered sudangrass (Sorghum sudanense) ad libitum, were used in a replicated 4×4 Latin Square experiment to evaluate the effects of increasing levels of canola meal supplementation on intake, digestibility, duodenal flow of N compounds and on N excretion. Four of the eight wethers were fitted with duodenal cannula. Treatments included no supplement (0) or daily supplementation with 5, 10 or 15g/kg BW of a canola meal mixture (nine parts canola meal one part cracked corn grain). Forage dry matter (DM) intake decreased linearly and total DM, organic matter (OM), digestible OM and N intake increased linearly with increasing levels of supplementation. Supplementation did not affect neutral (NDF) or acid detergent fiber (ADF) digestibility whereas it tended to improve DM and OM digestibility. Fecal and urinary N excretion, as well as duodenal flow of α-amino N and non-ammonia non-microbial N increased linearly with increasing levels of supplementation. Rumen microbial protein flowing to duodenum and the efficiency of rumen microbial protein synthesis were not affected by treatments. The proportion of rumen degradable protein which was used for microbial protein synthesis decreased linearly with increasing levels of supplementation, but at a higher rate than was the reduction of the proportion of N intake which reached the small intestine as α-amino N. In conclusion, despite increasing N excretion and exerting a depressive effect on forage intake, supplementation with a high-degradable true protein source improves α-amino N and energy supply in ruminants fed tropical grass based-diets.


      PubDate: 2014-12-18T17:34:52Z
       
  • Effects of Bacillus subtilis UBT-MO2 on growth performance, relative
           immune organ weight, gas concentration in excreta, and intestinal
           microbial shedding in broiler chickens
    • Abstract: Publication date: August 2013
      Source:Livestock Science, Volume 155, Issues 2–3
      Author(s): Z.F. Zhang , J.H. Cho , I.H. Kim
      This study was conducted to investigate the effects of Bacillus subtilis UBT-MO2 on growth performance, relative immune organ weight, gas concentration in excreta, and intestinal microbial shedding in broiler chickens. A total of 480 1-d-old mixed sex broilers were randomly allotted to a 2×2 factorial arrangement of treatments with 2 levels of enramycin (0 or 5ppm) and B. subtilis (0 or 105 cfu/kg) for 35d. Each treatment had 6 replicate pens with 20 broilers in each pen. Diets were fed in 2 phases: starter phase (from d 0 to 21) and grower phase (from d 22 to 35). Overall, broilers fed diets supplemented with B. subtilis had 4.4% greater (P=0.01) body weight gain than those fed non-probiotic diets. The feed conversion ratio in broilers fed diets containing enramycin was decreased by 2.8% and 4.2% during d 0–21 (P=0.05) and throughout the experimental period (P=0.02), respectively, than those fed diets without antibiotic. Broilers fed B. subtilis diets had 30.9% greater (P=0.02) relative weight of thymus than those fed diets without probiotic. Dietary supplementation with B. subtilis resulted in 26.9% and 37.9% lower (P=0.03) NH3 and H2S concentrations, respectively, in excreta compared with no supplementation. However, no differences were observed in intestinal bacterial concentrations among treatments. In conclusion, dietary supplementation with 105 cfu/kg of B. subtilis could improve the growth performance of broiler chickens, and reduced NH3 and H2S emissions.


      PubDate: 2014-12-18T17:34:52Z
       
  • A meta-analytical study about the relation of blood plasma addition in
           diets for piglets in the post-weaning and productive performance variables
           
    • Abstract: Publication date: August 2013
      Source:Livestock Science, Volume 155, Issues 2–3
      Author(s): A. Remus , I. Andretta , M. Kipper , C.R. Lehnen , C.C. Klein , P.A. Lovatto , L. Hauschild
      The meta-analysis was used to evaluate the performance of piglets in post-weaning period, without imposition of sanitary challenge and fed diets containing blood plasma, obtained by spray-dried process (SDBP). Piglets are faced with normal challenges in post-weaning period such as environmental stress and the substitution of the liquid diet to a solid one. References regarding sanitary challenges were disregarded in this study. Only data regarding normal and expected challenges were considered. Data were obtained from indexed journals with information extracted from the material, methods and results sections of pre-selected scientific articles. First, the database was analyzed graphically to observe the distribution of data and presence of outliers. Afterwards correlation analysis and variance–covariance analyses were carried out. The database contained a total of 23 articles. The average initial weight of the piglets was 8.02kg (4.00–9.28kg) and the average initial age was 27 days (14–32 days). The average duration of feeding diets containing spray-dried blood plasma (SDBP) was 9 days (6–28 days). SDBP increased the feed conversion by 20.2% (P<0.05) during the initial period. Feed conversion during the total period was 10.2% higher (P<0.05) for animals fed with SDBP. Average daily weight gain and daily feed intake were not affected (P>0.05) during the entire period, but average daily gain was higher (P<0.05) for animals fed with SDBP during the initial period. The initial age of supplementation influenced the average daily weight gain and average daily feed intake of animals fed with SDBP. Better results were obtained than those obtained for animals up to 35 days of age fed diets without added SDBP supplementation. In early post-weaning period for piglets weaned up to 35 days of age, the SDBP supplementation positively influenced the average daily weight gain and feed conversion.


      PubDate: 2014-12-18T17:34:52Z
       
  • The relationships between scrotal surface temperature, age and sperm
           quality in stallions
    • Abstract: Publication date: October 2013
      Source:Livestock Science, Volume 157, Issue 1
      Author(s): Carlos Ramires Neto , Gabriel Augusto Monteiro , Diego José Zanzarini Delfiol , Marcel Cavalcanti Farras , José Antônio Dell'aqua Jr. , Frederico Ozanan Papa , Marco Antonio Alvarenga
      In horses, spermatogenesis normally occurs at an average intratesticular temperature of 35°C; therefore, mechanisms for testicular thermoregulation are essential. Measuring the scrotal surface temperature by thermography is one of the methodologies used to evaluate the effectiveness of testicular thermoregulation. The objective of this study was to determine the relationship between the control of scrotal surface temperature and sperm quality in horses of different ages. In total, 24 Quarter Horse stallions were divided into three groups: YS (young stallions), AS (adult stallions) and OS (old stallions). Initially, we calculated the testicular volume (TV) and evaluated various aspects of the semen (sperm kinetics, plasma membrane integrity and sperm morphology) for all the animals. We also evaluated rectal temperature (RT), body surface temperature (BST,) and average scrotal surface temperature in the testicular region (SST) before (M0) and after sun exposure (M1). Differences were observed (p<0.05) between the RT and BST before and after sun exposure in all three groups. However, there were no differences (p>0.05) in the SST values at these two time points, thus demonstrating the efficiency of the mechanisms for testicular thermoregulation. The SST was similar (p>0.05) among all three groups. Based on these results, we conclude that fertile stallions of different age groups are able to maintain SST and measuring the heat radiating from the scrotum using a digital infrared thermographer. We can also conclude that measuring the heat radiating from the scrotum using a digital infrared thermographer is a practical and efficient tool for monitoring SST in horses.


      PubDate: 2014-12-18T17:34:52Z
       
  • Influence of high levels of maltodextrin in horse diets
    • Abstract: Publication date: August 2012
      Source:Livestock Science, Volume 147, Issues 1–3
      Author(s): P.C. Nunes Gil , J.R. Gandra , F.M.P. Taran , I.V.F. Gonzaga , A.A.O. Gobesso
      The aim of this study was to determine the effect of replacing starch with dietetic maltodextrin (MD) on apparent digestibility and glycemic and insulinemic response. Four mares aged approximately 30±2 months, and body weigh 385±23kg were randomly assigned to a 4×4 Latin square experimental design. The experimental diets were composed of 50% concentrate and 50% forage. The concentrate portion did not contain grains, but commercial starch was added to the control diet (CC) at 50%. Portions of commercial starch were replaced with MD at 33% (C1), 66% (C2), and 100% (C3). Mares were fed twice a day, at 7:00 am and at 7:00 pm. Total daily fecal output was collected over 5 (five) days, with animals kept at stalls without bedding. Blood samples were obtained from jugular vein 30min before (−30), and 30, 90, 150 and 210min after 7:00 am meal at 11th day of each period. No significant difference was observed in feces pH among diets. Apparent digestibility of C3 was higher for dry matter, organic matter, and crude protein, neutral detergent fiber and acid detergent fiber than C1. There was observed quadratic effect for area under the curve (AUC) for glucose and insulin concentration. There was no observed effect of diet and interaction of glucose, only a time effect, but a diet effect was observed for insulin concentration. The inclusion of MD can be added to equine diets in replacement of starch with good results in digestibility. Complete substitution of dietetic starch by maltodextrin provides more glucose for longer, increasing energetic balance. More studies must be done to establish comparisons between dietetic MD and cereal grains starch.


      PubDate: 2014-12-18T17:34:52Z
       
  • Study of using marker assisted selection on a beef cattle breeding program
           by model comparison
    • Abstract: Publication date: August 2012
      Source:Livestock Science, Volume 147, Issues 1–3
      Author(s): F.M. Rezende , J.B.S. Ferraz , J.P. Eler , R.C.G. Silva , E.C. Mattos , N. Ibáñez-Escriche
      A data set of a commercial Nellore beef cattle selection program was used to compare breeding models that assumed or not markers effects to estimate the breeding values, when a reduced number of animals have phenotypic, genotypic and pedigree information available. This herd complete data set was composed of 83,404 animals measured for weaning weight (WW), post-weaning gain (PWG), scrotal circumference (SC) and muscle score (MS), corresponding to 116,652 animals in the relationship matrix. Single trait analyses were performed by MTDFREML software to estimate fixed and random effects solutions using this complete data. The additive effects estimated were assumed as the reference breeding values for those animals. The individual observed phenotype of each trait was adjusted for fixed and random effects solutions, except for direct additive effects. The adjusted phenotype composed of the additive and residual parts of observed phenotype was used as dependent variable for models' comparison. Among all measured animals of this herd, only 3160 animals were genotyped for 106 SNP markers. Three models were compared in terms of changes on animals' rank, global fit and predictive ability. Model 1 included only polygenic effects, model 2 included only markers effects and model 3 included both polygenic and markers effects. Bayesian inference via Markov chain Monte Carlo methods performed by TM software was used to analyze the data for model comparison. Two different priors were adopted for markers effects in models 2 and 3, the first prior assumed was a uniform distribution (U) and, as a second prior, was assumed that markers effects were distributed as normal (N). Higher rank correlation coefficients were observed for models 3_U and 3_N, indicating a greater similarity of these models animals' rank and the rank based on the reference breeding values. Model 3_N presented a better global fit, as demonstrated by its low DIC. The best models in terms of predictive ability were models 1 and 3_N. Differences due prior assumed to markers effects in models 2 and 3 could be attributed to the better ability of normal prior in handle with collinear effects. The models 2_U and 2_N presented the worst performance, indicating that this small set of markers should not be used to genetically evaluate animals with no data, since its predictive ability is restricted. In conclusion, model 3_N presented a slight superiority when a reduce number of animals have phenotypic, genotypic and pedigree information. It could be attributed to the variation retained by markers and polygenic effects assumed together and the normal prior assumed to markers effects, that deals better with the collinearity between markers.


      PubDate: 2014-12-18T17:34:52Z
       
  • Goblet cell mucin distribution in the small intestine of newborn goat kids
           fed lyophilized bovine colostrum
    • Abstract: Publication date: October 2013
      Source:Livestock Science, Volume 157, Issue 1
      Author(s): R. Machado-Neto , M.C.F. Pontin , W.M. Nordi , A.L. Lima , D.B. Moretti
      The number of goblet cells containing neutral and acidic mucins, including sulphomucins and sialomucins, was investigated in the small intestine of goat kids fed with lyophilized bovine colostrum in the period of passive immunity acquisition. At 0, 7 and 14h of life, 15 male newborns received 5% of body weight of lyophilized bovine colostrum (LBC) and 14 male newborns received goat colostrum (GC), both with 55mg/mL of IgG. Three additional animals were sampled at birth, without colostrum intake. Duodenum, jejunum and ileum samples were collected at 18, 36 and 96h of life. Histological stains, periodic acid-Schiff, 1% alcian blue pH 2.5 and 1% alcian blue pH 1.0 were used to identify neutral and acidic mucins and acidic sulphated mucins, respectively. The number of goblet cells containing neutral and acidic mucins, including sulphomucins and sialomucins, does not differ in the duodenum (P>0.05). In the jejunum, LBC showed a higher number of goblet cells containing sialomucins compared to GC (P<0.05). The highest number of goblet cells containing acidic and neutral mucins and total number of goblet cells were observed at 96h (P<0.05). In this segment, vacuoles of colostrum were present at 18 and 36h mainly in the upper region of the villi, while the goblet cells were located at the bottom. At 96h, vacuoles of colostrum were not detected, only goblet cells distributed throughout the villi. In the ileum, the number of goblet cells containing sulphomucins was higher (P<0.05) at 96h than at 18h. The LBC group showed higher (P<0.05) number of goblet cells containing sulphomucins at 96h and total number of goblet cells at 36 and 96h than the 0-h group. The present work revealed that the greater the absorption of colostrum in the goat kids' jejunum epithelium, the smaller the number of goblet cells. Considering this segment, feeding newborns with heterologous colostrum caused alteration in the number of goblet cells containing sialomucin. This condition suggested a reaction of the intestinal epithelium with increasing secretion due to the presence of non-recognized substances from the lyophilized bovine colostrum.


      PubDate: 2014-12-18T17:34:52Z
       
  • IGF-I, GHR and UCP mRNA expression in the liver and muscle of high- and
           low-feed-efficiency laying Japanese quail at different environmental
           temperatures
    • Abstract: Publication date: October 2013
      Source:Livestock Science, Volume 157, Issue 1
      Author(s): Eliane Gasparino , Débora Marques Voltolini , Ana Paula Del Vesco , Simone Eliza Facioni Guimarães , Carlos Souza do Nascimento , Adhemar Rodrigues de Oliveira Neto
      In this study, we analyzed insulin-like growth factor I (IGF-I), growth hormone receptor (GHR) and uncoupling protein (UCP) mRNA expression in the muscle and liver of high- (0.23g/g) and low- (0.17g/g) feed-efficiency (FE) Japanese quail at three different air temperatures: comfortable (25°C), heat stress (38°C) for 12h or cold stress (10°C) for 12h. Total RNA was extracted from the liver and breast muscle of each quail, and cDNA was amplified using specific primers for the target genes. Expression was analyzed using quantitative real-time PCR (qRT-PCR). IGF-I mRNA expression was higher in the livers of high-FE quail than in the livers of low-FE quail under both heat and cold stress conditions. High-FE birds also showed higher GHR mRNA expression independent of temperature. UCP mRNA expression in the liver was lower in high-FE birds and higher under heat stress compared with the other conditions. IGF-I mRNA expression was higher in the muscle of high-FE quail under the three conditions tested, and UCP mRNA expression was higher under cold stress. Our results suggest that air temperature affects the expression of genes related to growth and mitochondrial energy production, and quail with different feed efficiencies respond differently to environmental stimuli.


      PubDate: 2014-12-18T17:34:52Z
       
  • Luteolysis after the intravulvosubmucosal injection of prostaglandin
           F2α in cattle: Systemic or local mechanism?
    • Abstract: Publication date: September 2012
      Source:Livestock Science, Volume 148, Issues 1–2
      Author(s): M.T. Rovani , M.H. Barreta , R. Ferreira , B.G. Gasperin , A.Q. Antoniazzi , R. Festugatto , J.F.C. Oliveira , P.B.D. Gonçalves
      The intravulvosubmucosal (IVSM) route has been used to reduce the dose of prostaglandin F2α (PGF2α), a luteolytic agent used in estrus synchronization programs. To validate the effectiveness of PGF2α administered via IVSM, the estrus rate was monitored in 1937 beef cows for 5 days (25.6% of estrus). The cows that did not show signs of estrus by day 5 received 5mg of dinoprost IVSM (1/5 of the standard dose; n=1440). By day 10, 68.2% of the cows were in estrus. In a second trial, using the same synchronization protocol, the proportion of heifers in estrus after receiving 5mg dinoprost at day 5 via IVSM (47.4%; n=97) or via an intramuscular injection (IM; 54.7%; n=95) did not differ (P>0.05). The occurrence of luteolysis (serum progesterone concentrations below 1ng/mL) was dependent on the period of the estrous cycle in which the cows were treated with 5mg of dinoprost via IM or IVSM. Luteolysis was observed in 5 out of 10 cows treated at day 10 but was not observed in any cows treated at day 5 of the estrous cycle. Luteolysis occurred in all animals treated with 25mg dinoprost independent of the estrous cycle period (day 5 or 10). After IVSM injection, the PGF2α concentration did not differ in the uterine and jugular veins. This was further confirmed by measuring the concentration of 13,14-dihydro-15-keto-PGF2α (PGFM) after the injection of 5mg of dinoprost via the IM or IVSM route. Dinoprost IM and IVSM injections resulted in a similar PGFM serum pattern over time, indicating the same rate of absorption into the systemic circulation. Taking the results together, we concluded that PGF2α IVSM injections reached the systemic circulation before reaching the ovary, and the effectiveness of low doses of PGF2α was dependent on the period of the estrous cycle and not on the route of administration.


      PubDate: 2014-12-18T17:34:52Z
       
  • First studies on a new concept for amino acid provision through B.
           subtilis in situ valine production in young pigs
    • Abstract: Publication date: August 2012
      Source:Livestock Science, Volume 147, Issues 1–3
      Author(s): J.V. Nørgaard , N. Canibe , B. Nielsen , D. Carlson , I. Knap , M.D. Cantor , H.D. Poulsen
      Supplementation of crystalline amino acids is common in diets for piglets. The purpose of the present experiment was to conduct a study on an alternative amino acid provision by means of feeding piglets spores of a B. subtilis strain known to overproduce Val when cultured in vitro. Seventeen individually penned piglets per treatment were used. One week after weaning, piglets were fed one of 3 diets: a Val deficient (Val:Lys, 0.63:1; Neg), the same diet with added 1.28×106 cfu B. subtilis/g feed (+Bac), or a diet containing Val at requirement levels for piglets (Val:Lys, 0.69:1; +Val). During the 26-d feeding period, Val deficiency reduced (P<0.001) feed intake and growth rate of piglets, and supplementation of B. subtilis spores was not effective enough to compensate for the Val deficiency. Although there were some effects on mucosa, the dietary treatments did not have major effects on amino acid concentrations in digesta and mucosa of the small intestine. However, the Val concentration in plasma of the portal and jugular veins and the urea concentration in plasma of the jugular vein were higher when piglets were fed the +Val diet. The Val:Lys of 0.63:1 was clearly below the requirement of Val for piglets. The dietary supplementation of the B. subtilis strain that can overproduce Val, did not provide Val in levels high enough to compensate for a Val deficiency. Further investigations should focus on optimizing strains to greater Val overproduction in the gastrointestinal tract of pigs and establishing the optimal dose of B. subtilis supplementation.


      PubDate: 2014-12-18T17:34:52Z
       
  • Application of a nonlinear optimization tool to balance diets with
           constant metabolizability
    • Abstract: Publication date: December 2013
      Source:Livestock Science, Volume 158, Issues 1–3
      Author(s): Júlia Gazzoni Jardim , Ricardo Augusto Mendonça Vieira , Alberto Magno Fernandes , Raphael Pavesi Araujo , Leonardo Siqueira Glória , Nardele Moreno Rohem Júnior , Norberto Silva Rocha , Matheus Lima Correa Abreu
      The goals of this study were to evaluate the ability of a nonlinear optimization tool to provide solutions for maintaining consistent qualities of diets irrespective of the plane of nutrition ( L ) and to evaluate the effect of the plane of nutrition on intake and digestibility of dry matter ( D M ) , organic matter ( O M ) , crude protein ( C P ) , crude fat ( C F ) , non fibrous carbohydrates ( N F C ) , neutral detergent fiber ( N D F ) , and metabolizability ( q m ) of diets using sheep as a generalized experimental model. Eight wethers were randomly assigned to two balanced four-treatment Latin squares conducted simultaneously with four diets providing nutritional levels that were multiples of maintenance levels ( M E = M m ; 1.5 M m ; 2 M m ; and 2.5 M m , where M E is the metabolizable energy intake, and M m is the metabolizable energy intake for maintenance). The M E , M m , metabolizable protein ( M P ) and N D F of the diet were subjected to nonlinear constraints; the model was considered a general nonlinear programming problem and solved using Microsoft Excel Solver® with Newton's method of resolution. The intake of nutrients, digestible nutrients, digestible energy ( D E ) and the amounts of feces and urine produced daily were measured and analyzed statistically by fitting a linear mixed model. The corrected metabolizability ( q m ' ) and plane of nutrition ( L c ) were obtained on the basis of the digestible, urinary, and simulated methane losses. The trends of some variables were reanalyzed by regressing observed values against L c . All measured variables were affected by L . The intakes of D M and O M increased in an asymptotic fashion as L c increased, whereas the intake of N D F increased linearly as L c increased. At levels immediately below maintenance, observed values were approximately constant. Digestible amounts of O M , D E , C F , and C P
      PubDate: 2014-12-18T17:34:52Z
       
  • Differences in preferences for breeding traits between organic and
           conventional dairy producers in Sweden
    • Abstract: Publication date: April 2014
      Source:Livestock Science, Volume 162
      Author(s): T. Ahlman , M. Ljung , L. Rydhmer , H Röcklinsberg , E. Strandberg , A. Wallenbeck
      Development of sustainable breeding goals for dairy production has to consider the producers' preferences which are likely to differ between production systems. The number of dairy producers with herds certified according to the standards of organic production has increased during the last decades. Traditionally, organic producers use animals selected in conventional production systems but the traits important in organic herds have been suggested to differ due to the different production conditions. The aim of this study was to assess what traits Swedish organic and conventional dairy producers consider to be important for the cows in their herds, and the relative importance of traits in the two production systems. An advanced web questionnaire with an underlying selection index was developed. The selection index was not shown to the respondents but it enabled them to weight traits against each other based on the genetic progress obtained. The questionnaire also included questions about what traits the producers intuitively considered important for the cows in their herds and how they ranked 15 given production and functional traits. The questionnaire was answered by 468 Swedish dairy producers of which 122 had a certified organic herd and 346 had a conventional herd. The results of this study show that the trait longevity was ranked first by both organic and conventional Swedish dairy producers. However, the ranking differed to some extent between the production systems for other traits, e.g. mastitis resistance and milk production. Swedish producers with organic herds tended to desire a higher genetic gain in disease resistance, including mastitis and parasite resistance, compared with producers with conventional herds. The results also reflect a somewhat lower interest in milk production level among producers with organic production. However, as the traits most important for Swedish producers with organic herds are already considered in the current Nordic breeding goal they can continue the use of this animal material.


      PubDate: 2014-12-18T17:34:52Z
       
  • Stable isotopes for determining carbon turnover in sheep feces and blood
    • Abstract: Publication date: November 2012
      Source:Livestock Science, Volume 149, Issues 1–2
      Author(s): M.B. Martins , C. Ducatti , C.L. Martins , J.C. Denadai , A.S. Natel , C.R. Souza-Kruliski , M.M.P. Sartori
      The objective of this work was to evaluate carbon turnover and half-life in feces and blood from sheep fed on C3 and C4 plant diets, using the stable isotope technique. Eight Santa Ines sheep were randomly distributed between two treatments: the first consisted of animals that were fed alfalfa hay, and the second consisted of animals that were fed corn silage only. Function of time was used to measure carbon turnover rate. At steady state, the half life for carbon isotopic enrichment between food and feces is 1.2 and 1.0 days for alfalfa hay and corn silage treatments, respectively. For blood data collection the time was insufficient to reach the isotope equilibrium level, indicating a slow carbon exchange between diet and blood. It is concluded that blood has a slow turnover, indicating the isotope signal for the former diets. Feces, by contrast, have a quick turnover, indicative of their recent diets.


      PubDate: 2014-12-18T17:34:52Z
       
  • Use of multivariate analysis to evaluate genetic groups of pigs for
           dry-cured ham production
    • Abstract: Publication date: October 2012
      Source:Livestock Science, Volume 148, Issue 3
      Author(s): Henrique T. Ventura , Paulo S. Lopes , José V. Peloso , Simone E.F. Guimarães , Antonio P.S. Carneiro , Paulo L.S. Carneiro
      Records of a pig population used for dry-cured ham production were used to evaluate genetic groups by multivariate analysis. The investigated genetic groups were as follows: DULL=Duroc×(Landrace×Large White), DULA=Duroc×Landrace, DUWI=Duroc×Large White, WIWI=Large White and DUDU=Duroc. Two groups were obtained for the carcass traits hot carcass weight (HCW), backfat thickness (BT) and loin depth (LD), with the groups including 597 and 341 animals harvested at 130kg and at 160kg weights, respectively. Two groups were also found for ham traits gross ham weight (GHW), trimmed ham weight (THW), ham inner layer fat thickness (HIFT), ham outer layer fat thickness (HOFT), pH (PH), and Göfo value, with 393 and 91 animals harvested at 130kg and 160kg weights, respectively. The analysis was performed within each group of traits and harvest weights, and the animals without records were excluded. The first and the second canonical variables explained 97.5% and 93.6% of the total variation for the carcass traits at 130kg and 160kg, respectively, and 88.8% of ham traits at 130kg. In the dispersion graph concerning the canonical means, a significant distance was observed between the genetic groups DUDU and WIWI for the carcass traits at 130kg and 160kg and the ham traits at 130kg. The 50% Duroc animals exhibited little dispersion regarding the carcass traits at 130kg and 160kg and were not divergent from the DUDU genetic group for the ham traits at 130kg. In a cluster analysis using the single linkage method, DULL, DULA and DUWI were grouped with a high similarity level for the carcass traits at 130kg and 160kg and ham traits at 130kg. Using the Tocher optimization method, 50% Duroc crossbred and 100% Duroc purebred animals were grouped for the ham traits at 130kg, suggesting that for ham traits, 50% Duroc animals were similar to 100% Duroc purebred animals. In this context, the genetic groups Duroc×Large White, Duroc×Landrace and Duroc×(Landrace×Large White) are recommended for use in producing dry-cured ham.


      PubDate: 2014-12-18T17:34:52Z
       
  • Feedlot performance, feed efficiency reranking, carcass traits, body
           composition, energy requirements, meat quality and calpain system activity
           in Nellore steers with low and high residual feed intake
    • Abstract: Publication date: December 2012
      Source:Livestock Science, Volume 150, Issues 1–3
      Author(s): R.C. Gomes , R.D. Sainz , S.L. Silva , M.C. César , M.N. Bonin , P.R. Leme
      The aim was to evaluate growth, carcass traits, feed efficiency reranking, body composition, calpain system activity and meat quality in Nellore steers that were phenotypically ranked for high and low residual feed intake (RFI). Seventy-two Nellore steers (16–21 month-old, 334±19kg BW) had free access to a feedlot diet for 70d (feeding period 1, P1). Daily dry matter intake (DMI), body weight gain (ADG) and ultrasound carcass traits were measured individually. The 12 lowest and the 12 highest RFI steers were classed as low- and high-RFI groups and were fed for a second feeding period (feeding period 2, P2). Spearman's rank correlation was performed for RFI and gain-to-feed ratio (G:F) measured over P1 and P2. The carcass traits, meat quality and calpain system activity were evaluated at slaughter, and body composition was determined. In P1, low-RFI steers had greater G:F (0.159 vs. 0.134; P<0.001), lower DMI (9.30 vs. 11.1kg/d; P<0.0001), lower RFI (−0.80 vs. 0.85kg/d; P<0.0001), and tended to have lower rates of rump fat gain (4.48 vs. 6.05mm; P=0.06), but no differences were observed for ADG, BW, and other traits measured by ultrasound (P>0.05). In P2, no differences between RFI classes were observed for G:F and DMI as a percentage of BW (P>0.05), and small differences were observed for DMI (8.25 vs. 8.99kg/d, P<0.05) and RFI (−0.28 vs. +0.29kg/d, P=0.06). The ranking correlations for RFI and G:F measured consecutively in P1 and P2 were low to moderate (r=0.11–0.40). Low-RFI steers had lower requirements of metabolizable energy (ME) for maintenance (131 vs. 160Mcal/kg EBW0.75 d−1, P<0.05), but no differences were observed for fat and protein gain, retained energy and efficiency of ME use for gain (P>0.05). No differences between low- and high-RFI steers were observed for carcass traits at slaughter; however, low-RFI steers had 8.1kg less gastrointestinal fat than high-RFI steers. There were no RFI effects on meat shear force and the activities of μ-calpain, m-calpain and calpastatin (P>0.05). High-RFI steers had greater MFI in 1d aged LM (53.9 vs. 40.8, P<0.05). The variation in feed efficiency between high- and low-RFI Nellore steers is related to differences in energy requirements and deposition of fat on internal organs. The ranking for feed efficiency is altered as cattle become older. The selection for improved RFI in Nellore cattle may reduce feed requirements for beef production without affecting meat tenderness and enzymatic activity of the calpain system.


      PubDate: 2014-12-18T17:34:52Z
       
  • Bayesian analysis of random regression models using B-splines to model
           test-day milk yield of Holstein cattle in Brazil
    • Abstract: Publication date: December 2012
      Source:Livestock Science, Volume 150, Issues 1–3
      Author(s): A.B. Bignardi , L. El Faro , M.L. Santana Jr. , G.J.M. Rosa , V.L. Cardoso , P.F. Machado , L.G. Albuquerque
      The objective of this paper is to model variations in test-day milk yields of first lactations of Holstein cows by RR using B-spline functions and Bayesian inference in order to fit adequate and parsimonious models for the estimation of genetic parameters. They used 152,145 test day milk yield records from 7317 first lactations of Holstein cows. The model established in this study was additive, permanent environmental and residual random effects. In addition, contemporary group and linear and quadratic effects of the age of cow at calving were included as fixed effects.
      Authors modeled the average lactation curve of the population with a fourth-order orthogonal Legendre polynomial. They concluded that a cubic B-spline with seven random regression coefficients for both the additive genetic and permanent environment effects was to be the best according to residual mean square and residual variance estimates. Moreover they urged a lower order model (quadratic B-spline with seven random regression coefficients for both random effects) could be adopted because it yielded practically the same genetic parameter estimates with parsimony.


      PubDate: 2014-12-18T17:34:52Z
       
  • Comparison of in vitro and in vivo fertilizing potential of bovine semen
           frozen in egg yolk or new lecithin based extenders
    • Abstract: Publication date: November 2012
      Source:Livestock Science, Volume 149, Issues 1–2
      Author(s): A.M. Crespilho , M.F. Sá Filho , J.A. Dell'Aqua Jr. , M. Nichi , G.A. Monteiro , B.R. Avanzi , A. Martins , F.O. Papa
      One of the main factors known to influence quality and fertility of bovine cryopreserved semen is the extender used. In this matter, a great worldwide interest has been directed to the development of chemically defined media, free of animal origin products. The objective of the present study was to compare the efficacy of three bovine semen extenders: Tris–fructose (TRIS, control with 20% egg yolk), Botu-Bov® (BB; 20% egg yolk), and Botu-Bov®-soy lecithin (BB-L; 1% soy lecithin). Towards this aim, post-thaw computer assisted sperm analysis (CASA), sperm membrane and acrosome integrity were evaluated (Experiment 1). Additionally, cryopreserved samples were used in a fixed time artificial insemination program aiming to evaluate in vivo fertility (pregnancy per insemination—P/AI; Experiment 2). Despite the higher straightness and linearity found for samples cryopreserved in BB and BB-L when compared to those cryopreserved in TRIS, egg yolk based extenders provided higher total and progressive motilities, percentage of rapid sperms and intact membrane cells (P<0.05). Furthermore, P/IA was higher in samples cryopreserved in egg yolk based extenders when compared to soy lecithin [TRIS=59.26a (64/108), BB=62.37a (58/93), and BB-L=36.45b (35/96)]. Although soy lecithin represents an alternative for the development of chemically defined extenders with decreased risk of biological contamination, egg yolk based extenders are more efficient on the preservation of bovine post-thaw sperm viability and fertility.


      PubDate: 2014-12-18T17:34:52Z
       
  • 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: 2014-12-18T17:34:52Z
       
  • Seasonal diet quality and metabolic profiles of steers grazing on
           Chihuahuan desert rangeland
    • Abstract: Publication date: July 2014
      Source:Livestock Science, Volume 165
      Author(s): M. Murillo-Ortiz , M. Mellado-Bosque , E. Herrera-Torres , O. Reyes-Estrada , F.O. Carrete-Carreón
      Four Angus steers (BW=350±3kg) with esophageal cannulae and four fitted with ruminal cannulas (BW=351±5kg) as well as fifteen steers of the same racial characteristics (BW=320±2kg), were used to evaluate seasonally across four years (2005–2009, excluding 2007) the nutritive quality of diet and the blood metabolites and insulin levels in grazing beef cattle a Chihuahuan desert rangeland. The diet consumed by grazing cattle during spring and winter was low quality because of crude protein (CP) was less than 70g/kg DM and neutral detergent fiber (NDF) higher than 720g/kg DM. Initial washing loss at time zero “A”, digestion rate “c”, effective degradability of NDF (EDNDF) and CP (EDCP), potential gas production (PGP), ruminal ammonia–nitrogen (NH3N), total volatile fatty acids (TVFA) propionate, butyrate, glucose (G), urea nitrogen (UN) and insulin were highest in summer compared to spring (P<0.05). In contrast, ruminal acetate concentrations and blood non-esterified fatty acids (NEFA) level were highest in spring as compared to summer (P<0.05). It was concluded that season of grazing had a marked influence on diet quality as well as in the blood metabolites and insulin levels in grazing beef cattle a desert rangeland.


      PubDate: 2014-12-18T17:34:52Z
       
  • Genomics to systems biology in animal and veterinary sciences: Progress,
           lessons and opportunities
    • Abstract: Publication date: August 2014
      Source:Livestock Science, Volume 166
      Author(s): Haja N. Kadarmideen
      Livestock genomics has gone through a paradigm shift since the advent of genome sequencing that includes Genome-Wide Association Studies (GWAS), Whole Genome Predictions (WGP) and Genomic Selection (GS). Beginning with a brief review of current progress and challenges in livestock GWAS, WGP and GS, opportunities for next generation methods are introduced that unravel the underlying systems genetics of complex traits and provide biologically meaningful and accurate predictions. Genome-Wide Epistasis Association (GWEA) and Weighted Interaction SNP Hub (WISH) network methods are introduced here to unravel complex trait genetics. These methods effectively address the problems of GWAS that have no ability to model and analyze genome-wide genetic interactions and thus do not capture any epistatic variance that could explain part of the missing heritability. Further, the Systems genomic BLUP (sgBLUP) prediction method is introduced in this paper as a next generation WGP or GS tool that can account for and differentiate SNPs with known biological roles in the phenotypic or disease outcomes and potentially increase the accuracy of prediction. It is emphasized that tools that link genetic variants to their functions, pathways and other biological roles will become even more important in the future. These tools include FunctSNP, Postgwas and NCBI2R which are briefly discussed. Genome-Wide Gene Expression (Transcriptomics) analyses using RNAseq technology are briefly discussed with some examples including results from our own pig experiments. In the last part of this review, systems genetics and systems biology approaches are introduced that involve joint modeling and analyses of multi-omics data types from genomics through transcriptomics (microarray and RNAseq), metabolomics to proteomics. It is shown using published studies that these systems approaches are valuable and powerful compared to stand-alone genomic methods in identifying key causal and highly predictive genetic variants for complex traits as well as in building up complex genetic regulatory networks. In all sections, some applications of next generation/-omics methods in livestock species (e.g. feed efficiency, growth, weight gain, fertility and disease resistance in cattle, pigs and sheep) are provided with references to relevant software and tools. In conclusion, this paper reviewed the current progress, lessons and challenges in livestock genomics and its ongoing transition to and opportunities for integrative systems genetics and systems biology in animal and veterinary sciences. Most of these integrative systems genetics and systems biology tools and methods presented here are equally applicable to plant and human genetics and systems biology.


      PubDate: 2014-12-18T17:34:52Z
       
  • Genomics and disease resistance studies in livestock
    • Abstract: Publication date: August 2014
      Source:Livestock Science, Volume 166
      Author(s): Stephen C Bishop , John A Woolliams
      This paper considers the application of genetic and genomic techniques to disease resistance, the interpretation of data arising from such studies and the utilisation of the research outcomes to breed animals for enhanced resistance. Resistance and tolerance are defined and contrasted, factors affecting the analysis and interpretation of field data presented, and appropriate experimental designs discussed. These general principles are then applied to two detailed case studies, infectious pancreatic necrosis in Atlantic salmon and bovine tuberculosis in dairy cattle, and the lessons learnt are considered in detail. It is concluded that the rate limiting step in disease genetic studies will generally be provision of adequate phenotypic data, and its interpretation, rather than the genomic resources. Lastly, the importance of cross-disciplinary dialogue between the animal health and animal genetics communities is stressed.


      PubDate: 2014-12-18T17:34:52Z
       
  • Endogenous fraction and urinary recovery of purine derivatives in Nellore
           and Holstein heifers with abomasal purine infusion
    • Abstract: Publication date: December 2012
      Source:Livestock Science, Volume 150, Issues 1–3
      Author(s): L.L. Prates , R.F.D. Valadares , S.C. Valadares Filho , E. Detmann , S.A. Santos , J.M.S. Braga , S.G. Pellizzoni , K.S. Barbosa
      The excretion of purine derivatives (PD) as an index of microbial biomass production in the rumen can be biased by the endogenous fraction and the incomplete urinary recovery of absorbed purines. Moreover, several authors have suggested differences for endogenous fraction of purine derivatives between genetic groups. The objective of this study was to estimate the endogenous fraction of PD and the urinary recovery of purines in Nellore and Holstein heifers fed diets containing 60% corn silage and 40% concentrate daily (13g dry matter/kg body weight). Daily creatinine excretion, intake and digestibility of dry matter and nutrients were also evaluated. Four Nellore heifers and four Holstein heifers fistulated at the rumen and abomasum, body weight of 270±7.76 and 225±7.16kg, respectively, were allocated in two 4×4 Latin squares. The experimental treatments consisted of four doses of RNA infusion (Torula Yeast): 0, 33, 66, or 100mmol/day. The endogenous losses of PD and the recovery of purine bases were estimated using a regression of the daily excretion of PD (Ŷ) and the abomasal flow of purine bases (X). There was no difference (P>0.05) between the regression equations for PD excretion and daily abomasal flow of purines for each genetic group, resulting in the following regression: Ŷ=0.405+0.923X, where 0.405mmol/kg0.75 and 0.923 represent the endogenous fraction and the recovery of purine bases in the abomasum, respectively, for both genetic groups. The infusion and genetic groups did not affect (P>0.05) the daily creatinine excretion, which averaged 27.23mg/kg BW. We concluded that there are no differences between Nellore and Holstein heifers in the endogenous fraction of PD, the urinary recovery of purines, and creatinine excretion, with average values of 0.405mmol/kg0.75, 0.92, and 27.23mg/kg BW, respectively.


      PubDate: 2014-12-18T17:34:52Z
       
  • Genomic evaluation of cattle in a multi-breed context
    • Abstract: Publication date: August 2014
      Source:Livestock Science, Volume 166
      Author(s): Mogens Sandø Lund , Guosheng Su , Luc Janss , Bernt Guldbrandtsen , Rasmus Froberg Brøndum
      In order to obtain accurate genomic breeding values a large number of reference animals with both phenotype and genotype data are needed. This poses a challenge for breeds with small reference populations. One option to overcome this obstacle is to use a multi-breed reference population. However, combining populations across breeds is not straightforward due to differences in linkage disequilibrium structure and weak relationships between breeds. This study offers a review of the available literature on the use of reference populations compiled from different cattle breeds. Results show that the effect of multi-breed reference populations on the accuracy of genomic prediction is highly affected by the genetic distance between breeds. When combining populations of the same breeds from different countries, large increases in accuracy are seen, whereas for admixed populations with some exchange of sires, substantial but smaller gains are found. Little or no benefit is found when combining distantly related breeds such as Holstein and Jersey and using the widely used genomic BLUP model. By using more sophisticated Bayesian variable selection models that put more focus on genomic markers in strong linkage disequilibrium with causative variants in combination with denser markers sets or functional subsets of markers, it is however possible to utilize information across distantly related breeds to increase the accuracy of genomic prediction. The further development of multi-breed genomic prediction models offers not only increases in the accuracy of genomic breeding values for small breeds, but will also give a stronger persistence of the accuracy over generations within larger breeds.


      PubDate: 2014-12-18T17:34:52Z
       
  • Animal-breeding schemes using genomic information need breeding plans
           designed to maximise long-term genetic gains
    • Abstract: Publication date: August 2014
      Source:Livestock Science, Volume 166
      Author(s): M. Henryon , P. Berg , A.C. Sørensen
      We argue that animal-breeding schemes need well-designed breeding plans to maximise long-term genetic gains from genomic information. Genomic information has been implemented in livestock breeding schemes with ad hoc breeding plans, suggesting that the potential benefits of genomic information are not being fully exploited. Breeding schemes need well-designed breeding plans to exploit the benefits of genomic information for two reasons. First, there are several components of breeding schemes with genomic information that impact on long-term genetic gains. Second, these components interact, which implies that breeding schemes need to optimise components simultaneously in order to maximise long-term genetic gains. Designing breeding plans that optimise components simultaneously is a complex task. In more cases than not, breeding schemes, their components, and interactions between these components do not allow optimum breeding plans to be designed by mere reasoning. We recommend using decision frameworks to design breeding plans for schemes that use genomic information: testing sound hypotheses by designing and executing controlled experiments using decision tools, such as mathematical–statistical models. These decision frameworks enable us to design optimum breeding plans by providing an objective and theoretical basis to make and validate breeding decisions, enabling us to understand the underlying mechanisms of breeding schemes with genomic information, and allowing us to test the practical implementation of breeding decisions against theoretical models. Genomic information is an exciting prospect for animal breeding, and there is clearly an important role for breeding plans that maximise long-term genetic gains in breeding schemes using genomic information.


      PubDate: 2014-12-18T17:34:52Z
       
  • Immunological effects of feeding macroalgae and various vitamin E
           supplements in Norwegian white sheep-ewes and their offspring
    • Abstract: Publication date: September 2014
      Source:Livestock Science, Volume 167
      Author(s): M. Novoa-Garrido , L. Aanensen , V. Lind , H.J.S. Larsen , S.K. Jensen , E. Govasmark , H. Steinshamn
      It is assumed that ewes raised in areas with long indoor winter feeding periods need to be supplemented with vitamins or other substances that help to maintain the health status of the animals. Various supplements are available on the market, but the most widely used supplemental antioxidant and vitamin E source is synthetic all-rac-α-tocopheryl acteate. The objective of the present study was to compare potential vitamin E and immune stimulant sources with synthetic vitamin E regarding bioactivity associated with immunological parameters in order to identify alternatives to synthetic vitamin E for small ruminants. Sources tested were meal of the seaweed Ascophylum nodosum and natural RRR-α-tocopheryl acetate. Forty pregnant ewes were randomly allocated to four treatment group with two replicates (5 ewes in each replicate). The treatments were supplements containing seaweed (SW: 546g Ascophylum nodosum/kg), natural vitamin E (NatE: 562.5mg RRR-α-tocopheryl acetate/kg), synthetic vitamin E (SyntE: 1125mg all-rac-α-tocopheryl acetate/kg), or no extra seaweed or vitamin E (control). The supplements were fed at an isoenergetic daily rate, on average 144g DM/ewe for SW and 114g DM/ewe for the three other treatments, from mating until start grazing season (200 days). It was assumed that 0.5mg RRR- α-tocopheryl acetate was equal to 1IU=1mg all-rac-α-tocopheryl acetate. The planned supplementation in the SyntE and NatE treatments were 140IU vitamin E/ewe daily, and the daily supplemental rate was on average for the whole experimental period 20, 146, 121 and 4IU in SW, SyntE, NatE and C treatments, respectively. The ewes and their newborn lambs were monitored throughout the entire indoor feeding period. Supplementing pregnant ewes with natural vitamin E had a positive effect on immunity against Mycobacterium sp. in the lambs, whereas supplementing ewes with seaweed interfered with the passive immunity of the offspring resulting in a mortality rate of 35%, compared with 10% in C, 5.6% in NatE and 0% in SyntE. The adaptive immunity of the lambs was not affected by seaweed supplementation. In the ewes, it seemed that supplementation with either seaweed, natural vitamin E or synthetic vitamin E had no beneficial health effects, and serum IgG concentrations were reduced in the seaweed treatment group.


      PubDate: 2014-12-18T17:34:52Z
       
 
 
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