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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  [2812 journals]
  • Growth performance and carcass characteristics of three chicken strains in
           response to incremental levels of dietary Moringa oleifera leaf meal
    • Abstract: Publication date: Available online 19 May 2015
      Source:Livestock Science
      Author(s): N.A. Sebola , V. Mlambo , H.K. Mokoboki , V. Muchenje
      A 90-day feeding trial was conducted to determine the effect of Moringa oleifera leaf meal supplementation on growth performance and carcass characteristics of three chicken strains (male and female) that are normally reared under extensive production systems in South Africa. Moringa leaves were harvested by hand, air-dried and milled into M. oleifera leaf meal (MOLM). The MOLM was chemically analysed and used to dilute a commercial broiler finisher diet at 0 (MOLM0), 25 (MOLM25), 50 (MOLM50), and 100 (MOLM100) g/kg DM, producing four dietary treatments. Two hundred and sixteen (216) Potchefstroom Koekoek (PK), Ovambo (OV) and Black Australorp (BA) chickens were raised on a commercial starter mash for 4 weeks. On the fourth week, experimental diets were offered and growth performance data were collected over a period of 13 weeks. Carcass characteristics were measured upon slaughter at the end of the 13-week feeding period. Diet× strain interaction was significant (P< 0.001) for feed intake but not (P>0.05) for growth rate and FCE. Feed intake responded to incremental levels of MOLM in an asymptotic fashion. Maximum feed intake was achieved at dietary MOLM inclusion levels between 50 and 70g/kg DM. Black Australorp chickens had the highest feed conversion efficiency (FCE) of 2.35, while OV and PK chickens had lower FCE values of 2.09 and 2.05, respectively. Diet, strain and gender, all had significant effects on dressing percent (P<0.001), leg and thigh weight (P<0.05), and wing weight (P<0.05). Male chickens attained higher (P<0.05) carcass weight, leg and thigh weight, dressing percent, and breast mass than female chickens (P<0.001). In female chickens, diets containing MOLM resulted in chickens with better carcass weight, leg and thigh weight, dressing percent, and breast mass compared to the control. In conclusion, Black Australorp chickens were better at utilizing diets with higher levels of MOLM compared to OV and PK strains. Inclusion of MOLM in chicken diets positively affected growth performance and carcass characteristics of the birds.


      PubDate: 2015-05-22T14:40:14Z
       
  • Effect of linseed dietary supplementation on adipose tissue development,
           fatty acid composition, and lipogenic gene expression in lambs
    • Abstract: Publication date: Available online 21 May 2015
      Source:Livestock Science
      Author(s): O. Urrutia , J.A. Mendizabal , K. Insausti , B. Soret , A. Purroy , A. Arana
      The objective of this study was to examine the effect of linseed supplementation on growth and carcass parameters, adipocyte cellularity, lipogenic enzyme activities, fatty acid (FA) composition and expression of lipogenic genes in subcutaneous (SC) adipose tissue and intramuscular (IM) adipose tissue of longissimus thoracis muscle of lambs. Thirty-six male Navarra breed lambs allocated into 3 experimental groups (15.2±0.18kg) were fed a control diet (containing barley and soya) and two experimental diets (5% and 10% linseed, L5 and L10 respectively) and slaughtered at 26.5±0.28kg. In the SC adipose tissue and muscle, the activity of fatty acid synthetase (FAS), glycerol 3-phosphate dehydrogenase (G3PDH), glucose 6-phosphate dehydrogenase (G6PDH) and NADP-Isocitrate dehydrogenase (ICDH) were studied and the expression of lipoprotein lipase (LPL), acetyl-CoA carboxylase 1 (ACACA), stearoyl-CoA desaturase (SCD), fatty acid desaturase 1 (FADS1) and 2 (FADS2) and fatty acid elongase 5 (ELOVL5) were quantified. Addition of linseed, rich in α-linolenic acid (C18:3n-3), had no effect on growth and carcass parameters. Linseed supplementation increased C18:3n-3, C18:1t10+C18:1t11 and total n-3 polyunsaturated fatty acid (PUFA) contents in SC and IM fat (P<0.001) and decreased C18:2n-6 and C18:3n-6 (P<0.05). The n-6/n-3 ratio was also decreased by linseed addition (P<0.05). There were no significant effects of linseed on C18:2c9,t11, eicosapentaenoic acid (C20:5n-3), docosapentaenoic acid (C22:5n-3) and docosahexaenoic acid (C22:6n-3) contents in SC and IM depots. In the SC fat, expression of ACACA and SCD was downregulated in L10 compared to C group (P<0.001) and LPL was upregulated in L5 group (P<0.001); however, there were no effects of diet on FADS1, FADS2 and ELOVL5 mRNA levels. In the IM fat, downregulation of ACACA (L5 and L10), SCD (L10), FADS1 (L5 and L10) and FADS2 (L5) was observed (P<0.001). Expression of LPL was upregulated in L5 compared to C group (P<0.01). It was concluded that dietary linseed raised C18:3n-3 and n-3 PUFA in SC and IM fat in Navarra breed lambs and modified the FA synthesis through the regulation of key-lipogenic gene expression. Dietary linseed regulated de novo FA synthesis and shifted monounsaturated FA formation at the transcriptional level by downregulating ACACA and SCD, respectively. Hence, linseed supplementation did not appeared to enhance the synthesis of C18:2c9,t11. Moreover, dietary PUFA affected the expression of genes involved in long chain PUFA synthesis (FADS1, FADS2 and ELOVL5) in a tissue-specific manner.


      PubDate: 2015-05-22T14:40:14Z
       
  • Effect of cysteamine Hydrochloride supplementation on the milk performance
           of dairy cow
    • Abstract: Publication date: Available online 21 May 2015
      Source:Livestock Science
      Author(s): C. Wang , C.J. Dong , Z.Q. Wang , F. Yang , H.L. Mao , Z. Wu , Q. Zhou , H.F. Wang
      Cysteamine (CS) can increase serum growth hormone concentrations and the growth performance of broiler, sheep, and pigs. However, information of CS supplementation on the milk performance of dairy cows is limited. An experiment was conducted to investigate the effect of dietary cysteamine hydrochloride (CSH) supplementation on lactation performance of dairy cows. Forty-eight multiparous mid-lactation Holsteins were fed a control diet or supplemented with 15, 30, or 45g/d CSH preparation (Cysteamine HCl 20%) for 63 d, including 7 d for adaptation. The base diet was formulated to meet the nutrient requirements of lactating dairy cows according to the Chinese feeding standard (China Standard NY/T 34, 2004) and the DMI, milk yield, milk composition, and plasma parameters were measured. Milk yield was 7.1 and 6.3% higher for the two higher supplementation amounts (SEM=0.50, P<0.05), and milk protein content was 7.7, 8.7, and 8.1% higher for the three supplemented groups (SEM=0.077, P<0.05), respectively, than the control. Plasma urea N were lower for the 30 and 45g/d CSH groups than for the control. Level of plasma somatostation was reduced and plasma growth hormone was enhanced in CSH groups compared with that of control (P<0.01). Supplementation of CSH preparation at 30g/d increased milk production of dairy cows while 15g/d has no positive effect on milk yield or milk efficiency.


      PubDate: 2015-05-22T14:40:14Z
       
  • Zn status of sows and piglets as affected by diet and sow parity
    • Abstract: Publication date: Available online 18 May 2015
      Source:Livestock Science
      Author(s): R. Davin , D. Solà-Oriol , E.G. Manzanilla , I. Kühn , J.F. Pérez
      The objective of the present study was to evaluate if changes to dietary P, Ca and phytase concentrations and sow parity number affect mineral transfer to piglets during lactation and productive and reproductive performance in sows. In experiment 1, sows (n=112) received the same gestation and lactation diets, and were grouped according to parity number. Colostrum and milk on d 21 of lactation were sampled from sows and analyzed for Zn, Fe and Cu. Hair from piglets was also collected at the 21st day of lactation and analyzed for Zn. In experiment 2, sows (41) were distributed into 3 groups based on parity and 4 dietary lactation treatments: dietary treatments were a lactation diet with recommended concentrations of Ca, P and Zn (Rec), a lactation diet with concentrations of Ca, P and Zn (Low0), the Low diet supplemented with 250 FTU of phytase/kg feed (Low250), and the Low diet supplemented with 500 FTU of phytase/kg feed (Low500). Titanium dioxide (TiO2) was added as indigestible marker to all diets. Fecal samples were obtained between d 21 and 25 of lactation and analyzed for Ca, P, Zn, Fe, Cu and Ti. Blood and colostrum samples were obtained on day of farrowing, and blood and milk samples were collected on d 21, for Zn, Fe and Cu analysis. In Experiment 1, no differences in trace minerals were observed between parity groups for colostrum, milk and hair except milk Cu concentrations were greater in older sows (6th–10th parity number) and milk Zn concentrations tended to be greater in older (6th–10th parity number) sows. In Experiment 2, sows fed Rec had greater intake and excretion of Ca, P and Zn than the other three treatments. Sows supplemented with phytase (Low250 and Low500) had greater P digestibility than those without phytase (Rec and Low0). Zn, Fe and Cu concentrations in plasma and milk did not change with treatment. Parity did not alter any of the variables measured except plasma Cu levels, which were greater following farrowing in youngest sows. Large amounts of Zn are secreted in milk in relation to the body Zn stores during lactation. This research suggests the amount secreted appears to be constant and independent of parity or phytase use in lactation diets low in P and Ca.


      PubDate: 2015-05-22T14:40:14Z
       
  • Effects of maize crop maturity at harvest and dietary inclusion rate of
           maize silage on feed intake and performance in lambs fed High-concentrate
           diets
    • Abstract: Publication date: Available online 18 May 2015
      Source:Livestock Science
      Author(s): Carl Helander , Peder Nørgaard , Konstantinos Zaralis , Kjell Martinsson , Michael Murphy , Elisabet Nadeau
      This study investigated the effects of maize maturity at harvest and dietary inclusion rate of maize silage on feed intake, average daily gain (ADG) and carcass traits of growing ram lambs fed high-concentrate diets. Precision-chopped maize was harvested at two stages of maturity (Early: dough stage and Late: dent stage) and ensiled as round bales. Early or late cut maize silage was fed as the sole forage or together with grass silage, to 40 ram lambs in each of two consecutive years. The four treatments in each year were: 1. early cut maize silage as 50% of the forage dry matter (DM) proportion (E50), 2. early cut maize silage as 100% of the forage DM proportion (E100), 3. late cut maize silage as 50% of the forage DM proportion (L50) and 4. late cut maize silage as 100% of the forage DM proportion (L100). The proportion of forage in each of the diets was on average 42% on a dry matter (DM) basis and the concentrate consisted of dried distillers’ grains plus solubles, rolled barley and cold-pressed rapeseed cake in year 1 (Y1) or heat-treated rapeseed expeller in year 2 (Y2). Daily DM intake (DMI) was 1.24 and 1.40kg, averaged over treatments, in Y1 and Y2, respectively. Increasing the dietary inclusion rate of maize silage from 50 to 100% of the forage DM proportion resulted in increased DMI in Y1 (P<0.05) and increased carcass fatness in Y2 (P<0.01), whereas increased maturity stage at harvest tended to result in increased DMI in Y2 (P<0.10). Feed conversion ratio (FCR; kg DMI per kg ADG), was lower for the treatments E100 and L50 than for E50 and L100, respectively (P<0.01) in Y2. The body weight of the lambs increased linearly over time, in both years. In conclusion, maize silage can replace grass silage in the diets of high-producing lambs. Increased metabolizable protein (MP) to metabolizable energy (ME) ratio of the diet increased ADG of the lambs. Also, increased ADG decreased mega joule ME intake per kg ADG, in finishing lambs.


      PubDate: 2015-05-22T14:40:14Z
       
  • A survey of senior equine management: owner practices and confidence
    • Abstract: Publication date: Available online 18 May 2015
      Source:Livestock Science
      Author(s): R. Bushell , J. Murray
      Senior equines (16 years and over) comprise a significant proportion of the global equine population and there is concern that their management practices may not be entirely appropriate, particularly given recent evidence to suggest an under recognition of disease for which alterations are necessary to ensure optimal care. However, there has been minimal research to investigate the appropriateness of senior equine care and how capable their carers’ are in providing care. Consequently, this study used a survey approach to investigate the management practices and health care provision for senior equines. A series of likert type questions were used to assess respondent confidence in aspects of management regimes, recognition of age associated equine conditions, and perceived importance of nutrition advice sources, using a scale of 1–5 (1 being low and 5 high confidence). In addition, a combination of multiple response and open questions were used to report management practices in place. The survey was administered to those enrolled on a massive open online equine nutrition course and received 1342 responses. Results indicated an encouraging provision of care for senior equines, with associated high carer confidence in management regimes and concerted effort to understand and fulfil their senior equines requirements. However, the study highlighted key areas of requirements for owner education. In particular, the combined lack of frequent body condition monitoring and low confidence in disease recognition and supplement feeding. There was also a prevalence of suboptimal strategic worming and dry hay feeding. Given that veterinarians were consistently considered as the most important advice source it is likely that they will have an important role to play in the education that is required.


      PubDate: 2015-05-22T14:40:14Z
       
  • Editorial Board
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176




      PubDate: 2015-05-18T14:36:23Z
       
  • Modeling breed additive and non-additive genetic effects using a Angus x
           Nellore crossbred population
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Claudia Damo Bertoli , Jose Braccini , Connie McManus , Jaime Araujo Cobuci , Elisandra Lurdes Kern , Mario Luiz Piccoli , Flavio Schenkel , Vanerlei Roso
      The objectives of this study were to estimate fixed genetic (both additive and non-additive) effects and test different non-additive models. These effects included direct and maternal joint breed additive effects, direct and maternal complementarity (or profit heterosis), direct and maternal heterosis (dominance) and direct and maternal epistatic loss non-additive effects. A large crossbred Angus x Nellore population with approximately 300,000 records for weaning gain (WG) and 150,000 records for post-weaning gain (PG) was used. Phenotypic scores for weaning (WC) and post-weaning (PC) conformation, weaning (WP) and post-weaning (PP) precocity, weaning (WM) and post-weaning (PM) muscling and scrotal circumference (SC) were also used. All models included the fixed contemporary group effect and random animal, maternal genetic and permanent environment effects. Each model was tested against all other models for all nine traits using the likelihood ratio test. The complete model, including all additive and non-additive effects and the model without complementarity, were seen to be the best options to analyze this crossbred population. However, least squares may not be the best methodology due to possible collinearity among estimates that may inflate the variance. In the complete model most effects were statistically significant (P<0.01) for weaning traits, except for direct and maternal breed additive effects and direct complementarity effect for WM. For post-weaning traits, the direct complementarity effect for phenotypic scores (PC, PP and PM) and the maternal heterosis effect for PG, PC, PM, were not statistically significant. For scrotal circumference the maternal complementarity, direct and maternal heterosis and maternal epistatic loss effects were not statistically significant. All other effects were statistically significant (P<0.01). For the model without complementarity, the direct breed additive effect for PG and PP was not statistically significant, including the maternal breed additive effect for WC, WD, PP and PM and maternal heterosis, direct and maternal epistatic loss effects for SC. Considering all models, significant direct breed additive effect was mostly positive for weaning traits and was negative for all post-weaning and SC. The significant maternal breed additive and maternal complementarity effects for SC were all negative. The significant direct and maternal epistatic loss effects were negative for all traits and for all models, except for PG in the complete model and for weaning traits in the model including only breed additive and epistatic loss effects. We conclude that the fixed genetic effects are mostly significant, thus it is important to include them in the model when evaluating crossbreed animals and the models including breed additive effects, heterosis and epistatic loss with or without complementarity were the more appropriate.


      PubDate: 2015-05-18T14:36:23Z
       
  • Association of 20 candidate gene markers with milk production and
           composition traits in sires of Reggiana breed, a local dairy cattle
           population
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): L. Fontanesi , E. Scotti , A.B. Samorè , A. Bagnato , V. Russo
      Reggiana is a local dairy cattle breed that currently counts about 2000 cows reared mainly in the province of Reggio Emilia (North of Italy). Reggiana cows are less productive than Holstein cows opening questions about the profitability of this breed whose milk is used to produce a niche brand of Parmigiano-Reggiano cheese. For these reasons, protein content and yield of the Reggiana milk are very important traits. With the aim to identify markers that could be useful to describe genetic variability in this breed and eventually to use them in conservation and marker assisted selection programs, we genotyped 22 DNA polymorphisms of 17 candidate genes (ABCG2, CRH, CSN3, CYP11B1, DGAT1, FGF2, GH1, GHR, KIT, LEP, LGB, ORL1, POU1F1, PRLR, SPP1, STAT1 and TG) in 128 Reggiana sires for which semen was available and we analyzed association among 20 polymorphic markers and milk yield, protein yield (PY), fat yield (FY), protein percentage (PP) and fat percentage (FP) estimated breeding values. Five markers, four of which on Bos taurus chromosome (BTA) 14 (DGAT1 p.K232A, CYP11B1 p.A30V, TG g.9509279C>T, CRH p.S45D) and one on BTA19 (GH1 p.L153V), were highly associated (P<0.01) with several production traits (PP, FY and PY; FP; PY; FY; PP and FP; respectively). This study is the largest investigation of molecular markers carried out in this breed so far and represents one of the few attempts to identify DNA markers affecting production traits in a cattle breed constituted by a very small population. Obtained results could open new possibilities for conservation and breeding programs in Reggiana cattle.


      PubDate: 2015-05-18T14:36:23Z
       
  • Survival analysis of genetic and non-genetic factors influencing ewe
           longevity and lamb survival of Ethiopian sheep breeds
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): T. Getachew , S. Gizaw , M. Wurzinger , A. Haile , B. Rischkowsky , A.M. Okeyo , J. Sölkner , G. Mészáros
      Survival analysis applying proportional hazards models was used to investigate genetic and non-genetic factors affecting ewe longevity and lamb survival of sheep in Ethiopia. Data were obtained from an on-station closed nucleus breeding program of Menz sheep and an on-farm Awassi×Menz sheep crossbreeding project. A total of 695 ewes and 1890 lambs born from the nucleus population of Menz sheep were used for the analysis of ewe productive life and lamb survival to yearling age respectively. In addition, 5530 lamb records of purebred local and crossbreds with proportions of ~25–50% Awassi, collected from three locations were used for the analysis of lamb survival from birth to weaning age. The effects of year, ewe parity and litter weight at weaning were significant (p<0.05) for ewe productive life. On-station lamb survival to yearling was affected by year and breeding value of yearling weight of the lamb, indicating that faster growing animals had substantially higher survival rates. Animal model heritability estimates for lamb mortality ranged from 0.02 to 0.10. While there was a strong genetic trend for growth rate, as evidenced by estimated breeding values for different birth years, estimated breeding values for lamb survival were variable across years with decreasing trend. These results indicate no antagonism between growth rate and survival under conditions prevailing in the nucleus system. Routine genetic evaluation for survival is suggested. Under farmer conditions, the effects of year, season, sex and location effects were significant (p<0.05) on lamb survival to weaning age whereas breed composition (local versus crossbred) of dam as well as of the lamb were not significant. This seems to indicate that crossbreeding of local animals with Awassi sheep does not have an adverse effect on the survival of lambs under farmer conditions typical for the Ethiopian highland regions included in this study.


      PubDate: 2015-05-18T14:36:23Z
       
  • The importance of the DMRT3 ‘Gait keeper’ mutation on riding
           traits and gaits in Standardbred and Icelandic horses
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Kim Jäderkvist , Niina Holm , Freyja Imsland , Thorvaldur Árnason , Leif Andersson , Lisa S. Andersson , Gabriella Lindgren
      Previous studies have shown that a single base-pair mutation, a change from cytosine (C) to adenine (A), in the DMRT3 gene affects both the ability to show ambling and lateral gaits in a wide range of horse breeds, as well as racing performance and trotting technique in Standardbred and Nordic trotters. The variant allele is present in gaited breeds but is absent, or found at a very low frequency, in breeds used for Western-European style riding and flat racing, like the Swedish Warmblood and Thoroughbreds as well as in draught horses. This indicates that the variant allele might have a negative effect on certain riding performance traits in horses. Therefore, one aim of this study was to investigate whether the DMRT3 variant affects canter in Standardbred trotters, and to test if heterozygous horses (CA) were better suited for Western-European style riding than homozygous horses (AA). Riding traits were studied in 115 Standardbred horses, and a similar study was also performed with data from 55 Nordic trotters. The results showed that CA Standardbreds had significantly better balance in canter, both collected and extended canter, than AA horses. The CA horses also got significantly higher scores for transitions in collected canter. For the rhythm we found no significant differences between the genotypes. In the Nordic trotters we were unable to establish any significant difference for canter ability. Another aim of this study was to investigate the effect of the variant allele on riding abilities and gaits in the Icelandic horse (n=446). Practically all horse breeds considered to be three-gaited have a CC genotype, in contrast Icelandic CC horses can show tölt. We therefore tested whether the variant influenced how difficult it was to initiate tölt training for these horses. It was also investigated whether the variant affects which gaits Icelandic horses choose, both at liberty and during initial training. Icelandic CC horses were significantly more difficult to train to tölt compared to CA and AA horses. The AA Icelandic horses showed the lateral gaits tölt and pace significantly more frequent, both at liberty and during initial training, than CA or CC horses. The majority of the Icelandic CC and CA horses chose trot at liberty and during initial training.


      PubDate: 2015-05-18T14:36:23Z
       
  • Genotype×environment interaction for weaning weight in Nellore cattle
           using reaction norm analysis
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): S. Ribeiro , J.P. Eler , V.B. Pedrosa , G.J.M. Rosa , J.B.S. Ferraz , J.C.C. Balieiro
      This study aimed to evaluate the existence of genotype×environment interaction (G×E) for weaning weight in Nellore cattle, using reaction norms. Thus, 58,032 records of weaning weight adjusted to 205 days (WW) were analyzed, from animals born between 1987 and 2005, originating from three herds in different regions of Brazil. A random regression model was used to describe changes in breeding values according to the environmental gradient formed by different contemporary groups. Analyses were carried out utilizing INTERGEN software under a Bayesian approach. The solutions of contemporary groups distributed in the environmental gradient varied from −58 to +56kg, and estimates of direct heritability coefficients ranged from 0.05 to 0.44 through the environmental gradient. Genetic correlation between intercept and slope of the reaction norms was 0.75, and the correlation between breeding values of bulls in different environments ranged from −0.38 to 0.99, being higher in highly favorable environments. The results showed the effect of genotype×environment interaction on weaning weight in the herds of this study, especially on the bulls’ rankings. Thus, the authors emphasize the importance of considering the G×E in the genetic evaluation of Nellore cattle, which will result in increased selection efficiency in the weaning period.


      PubDate: 2015-05-18T14:36:23Z
       
  • Comparing multi-trait Poisson and Gaussian Bayesian models for genetic
           evaluation of litter traits in pigs
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Henrique Torres Ventura , Fabyano Fonseca e Silva , Luiz Varona , Elsio Antônio Pereira de Figueiredo , Edson Vinícius Costa , Luciano Pinheiro da Silva , Ricardo Ventura , Paulo Sávio Lopes
      Reproductive traits as number of piglets born (NPB) and weaned (NWP) are directly related to the economic efficiency of swine production systems. Pig breeding programs seek to increase the number of weaned piglets per sow per year, and the NPB is among the factors that directly and indirectly influence the NWP. Thus, multi-trait evaluations are essential to estimate heritabilities and mainly genetic correlations between these traits over different farrowing orders. In general, Gaussian linear mixed models have been used to genetic evaluation of litter traits; however since these traits are characterized as count variables, Poisson models are also indicated. Some studies were carried out using Poisson mixed models in the area of Animal Breeding and Genetics, but they do not point out for a multi-trait scenario, as it should be for litter size at birth and weaning. Toward this orientation, we aimed to apply a multi-trait Poisson mixed model (MPM) for the genetic evaluation of the number of born and weaned piglets under a Bayesian framework. It was aimed also to compare the proposed model with the traditional multi-trait Gaussian model (MGM) by using posterior based goodness-of-fit measures. Two-trait analyses for NPB and NWP were performed separately by each considered farrowing order (first, second and third) using MPM and MGM fitted to data from a commercial Landrace population. Based on DIC (Deviance Information Criterion) and PMP (Posterior Model Probability) values, the MGM outperformed the MPM, but the genetic parameter and breeding values provided by both models were consistent and similar over the three first farrowing orders. Bayesian generalized a multi-trait mixed model approach is feasible for genetic evaluations in the animal breeding context and can be an alternative method for genetic evaluations assuming non-Normal phenotypes.


      PubDate: 2015-05-18T14:36:23Z
       
  • Use of descriptors to define clusters of herds under similar environmental
           conditions to improve the level of connection among contemporary groups of
           mutton type merino sheep under an extensive production system
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): J. Osorio-Avalos , A. Menéndez-Buxadera , J.M. Serradilla , A. Molina
      An analysis of the genetic connections among the herds constituting the selection nucleus of the mutton type of Merino sheep in Spain has been carried out in order to improve the reliability of the genetic evaluations. Four climatic variables, registered in weather stations located near the farms, and 16 variables (10 of them related to the production and managing systems and other six related to production traits), registered in 23 farms, were subjected to a discriminant analysis, resulting in seven eigenvectors explaining 78.3% of the variance and four groups (clusters) of farms with similar values for formerly mentioned variables. The relative efficiency of the genetic evaluation models including these clusters of herds in respect to the conventional models including single herd effects was estimated through the analysis of 50,503 weights of lambs at 75 days of age (near weaning) using the method of Criterion of Admission to the Group of Connected Herds (CACO), which compares the average coefficients of determinations (CD) of the herds, which is a measure of the degree of connection among herds through common ancestors. Results obtained showed that the values of the contrasts of the CD of the herds were between 2.3% and 14.9% higher (depending on the heritability of the trait) when the model with the clusters was used. When other heritability estimates of weights at other ages were simulated, the increments of these contrasts ranged between 4.1% and 24.9%. These results suggest defining these new clusters grouping herds with similar climatic, managing and production environments is a good alternative to improve the connections and, consequently, may improve the reliability of the estimates of breeding values when connections among herds are poor due to the absence of artificial insemination.


      PubDate: 2015-05-18T14:36:23Z
       
  • Comparison of methods for estimating herbage intake in grazing dairy cows
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): A.L.F. Hellwing , P. Lund , M.R. Weisbjerg , F.W. Oudshoorn , L. Munksgaard , T. Kristensen
      Estimation of herbage intake is a challenge both under practical and experimental conditions. The aim of this study was to estimate herbage intake with different methods for cows grazing 7h daily on either spring or autumn pastures. In order to generate variation between cows, the 20 cows per season were either allocated to low or high stocking rate. At low stocking rate, there were 6.7 and 3.5 cows per hectare during spring and autumn, respectively, and at high stocking rate, there were 8.8 and 4.6 cows per hectare during spring and autumn, respectively. The experiment lasted 16 days in each season, and the herbage intake was estimated twice during each season. Cows were on pasture from 8:00 until 15:00, and were subsequently housed inside and fed a mixed ration (MR) based on maize silage ad libitum. Herbage intake was estimated with nine different methods: (1) animal performance (2) intake capacity, (3) content of 13C in faeces and diet, (4) 13C in faeces and diet, and with assumption of 13C discrimination in the digestive tract, (5) 13C in faeces and diet, with assumption of 13C discrimination and in combination with in vitro organic matter digestibility (IVOM), (6) simultaneous use of two internal markers (ingestible neutral detergent fibre (INDF) and acid detergent lignin (ADL)), (7) titanium oxide in combination with IVOM, (8) titanium oxide in combination with INDF and (9) titanium oxide in combination with ADL. Furthermore, grazing time of the individual cows was recorded. The estimated average herbage dry matter intake (DMI) varied from 2.2kg for the method using the INDF:ADL ratio to 7.6 for the methods using 13C and intake capacity. There was a low correlation between the different methods. Dry matter intake of herbage was not affected by stocking rate except for the method using titanium oxide and ADL as markers. Milk yield was not affected by stocking rate either. It was concluded that methods based on animal performance, 13C including discrimination factor or in combination with IVOM as well as methods based on titanium oxide gave similar estimates of the average herbage DMI intake during grazing in systems with indoor concentrate and forage feeding during night.


      PubDate: 2015-05-18T14:36:23Z
       
  • Changes in calculated residual energy in variable nutritional
           environments: An indirect approach to apprehend suckling beef cows’
           robustness
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): A. De La Torre , E. Recoules , F. Blanc , I. Ortigues-Marty , P. D’Hour , J. Agabriel
      The major perturbation that beef cows have to face in extensive livestock systems is changes in feed resource availability. The ability of beef cows to face variable nutritional environments (robustness) involves adaptive processes that drive adjustments in the energy allocation toward life functions. This study proposes an indirect approach to quantify the modulation of energy allocation over a changing nutritional environment. The concept of residual energy (E resid), defined as the net energy intake minus the energy secreted in milk and deposited in tissues, was used to investigate the variation in energy allocation priority for maintaining productive traits. In this study robustness was assessed by the difference in E resid between cows experiencing either variable or non limiting nutritional trajectories and differing in body reserves at calving. Forty multiparous Charolais suckling cows, differing in their body condition at calving (moderate (M, n=19): BCSc=2.0±0.04 (scale 0–5)) vs fat (F, n=18): BCSc=2.8±0.08) were used. They were submitted to two energy levels during the first 120 days post-partum (P1): Control (MC (n=9) and FC (n=9)) vs Low (ML (n=10) and FL (n=9)). The average energy intake, expressed in net energy for lactation (NEL), was 90.7 and 54.7MJ/d/cow for C and L cows, respectively. Subsequently (P2, 120–196 days post-partum) all the cows were turned out to a permanent pasture. BW, body condition and milk production were regularly measured in P1 and P2. Body lipid reserves were assessed at calving, end of P1 and end of P2 by measuring adipose cell diameter. The overall milk production was similar between groups of cows over the 2 phases of the changing nutritional trajectories highlighting the robustness of beef cows to achieve this function. During P1, L cows lost BW and body lipid reserves. During P2, BW and BCS gains were similar in FL and ML cows. At the end of P2, FL and ML cows weighed 20 and 10kg less than FC and MC cows, respectively. Considering both experimental periods (P1+P2), E resid was 23% lower in L than in C cows (P<0.05). This difference was observed regardless of BCSc, showing that thin beef cows withstood the change in nutritional trajectory after calving similarly to the fatter ones. E resid changes reflect the ability of beef cows to preserve energy allocation toward life functions in changing nutritional environments and may be viewed as indirect criteria of robustness.


      PubDate: 2015-05-18T14:36:23Z
       
  • The relationship of residual feed intake and visceral organ size in
           growing lambs fed a concentrate- or forage-based diet
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): A.M. Meyer , R.A. Vraspir , M.J. Ellison , K.M. Cammack
      We hypothesized that a portion of the individual differences observed for feed efficiency in ruminants can be attributed to gastrointestinal tract (GIT) size, which would vary based on diet type. The objective of this study was to determine GIT and visceral organ size in high and low efficiency growing lambs fed either a concentrate or forage-based diet. Growing wethers (n=82; 51.3±1.2kg body weight [BW]) were fed a concentrate (CONC; 12.1% crude protein [CP], 17.6% neutral detergent fiber [NDF], 2.98Mcal/kg metabolizable energy [ME]) or forage-based pelleted diet (FOR; 16.2% CP, 36.3% NDF, 2.31Mcal/kg ME) for 49d. Individual intake was measured with the GrowSafe System to determine residual feed intake (RFI). The 20% highest efficiency (low RFI, n=8) and 20% lowest efficiency (high RFI, n=8) lambs from each diet were slaughtered (66.6±2.3kg BW; n=32 total), and the viscera was dissected and weighed. Data were analyzed as a 2×2 factorial with RFI class (high efficiency vs. low efficiency), diet type (FOR vs. CONC), and their interaction in the model. Organ masses were not affected (P>0.10) by the RFI class x diet type interaction. High efficiency lambs tended to have greater (P=0.09) pancreas and spleen actual mass than low efficiency lambs, although RFI class did not affect (P>0.15) other organ actual (g) or relative (g/kg BW) mass. Lambs fed FOR had greater (P≤0.01) actual and relative reticulum, omasum, large intestinal, and kidney mass and tended to have greater (P≤0.09) actual and relative small intestinal masses compared with lambs fed CONC. However, lambs fed CONC had greater (P≤0.05) actual rumen, heart, liver, and relative rumen mass than lambs fed FOR. All other visceral organ masses were unaffected (P>0.11) by diet type. Diet type, RFI class, and their interaction did not affect small intestinal length (P>0.10). Results of this study suggest that visceral organ size in growing lambs is more affected by diet type than individual feed efficiency. Based on this data, pancreas and spleen sizes may play a role in efficiency of feed utilization in lambs, however.


      PubDate: 2015-05-18T14:36:23Z
       
  • Evaluation of five models predicting feed intake by dairy cows fed total
           mixed rations
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): L.M. Jensen , N.I. Nielsen , E. Nadeau , B. Markussen , P. Nørgaard
      The objective of this study was to evaluate the accuracy of five models predicting dry matter intake (DMI) in dairy cows fed total mixed ration (TMR). The five models were the North American model from NRC, and the Northern European models: NorFor (Denmark, Iceland, Norway, and Sweden), TDMI (Finland), Zom (the Netherlands), and Gruber (Austria, Germany, Switzerland). The evaluated models represent different approaches to predict DMI. One approach uses only animal characteristics; a second uses the interaction between animal and dietary characteristics, and a third uses no production characteristics, such as body weight or milk yield. These different modelling approaches results in very different substitution rates, where only two of the models demonstrate direct or indirect relation to concentrate allocation. Accuracy of DMI prediction was evaluated by mean square prediction error (MSPE), root mean square prediction error (RMSPE), together with the decomposition of error into error of central tendency (ECT), error of regression (ER), and error due to disturbance (ED). The evaluation was performed on data from 12 Scandinavian production experiments with a total of 917 lactating dairy cows in 94 treatment means. The NorFor model was evaluated on only 9 of the experiments as 3 experiments had been used in the development of this model. The five models predicted DMI in groups of dairy cows fed TMR with RMSPE ranging between 1.2kg dry matter (DM) per day for the Gruber model to 3.2kg DM per day for the Zom model. Evaluated across the experiment the ECT and the ER ranged between 0.3% and 65% and between 3% and 38% of MSPE, respectively. Error associated to ED ranged between 31% and 93% of MSPE. When all five models were evaluated for prediction of DMI both across and within experiments, results revealed that all five models predicted differences between diets within experiments better than differences across experiments. The Gruber model, which predicted DMI most accurately did so due to its negligible systematic error (ECT, ER) resulting in 93% of the error located in ED.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effect of replacing barley with wheat grain in finishing feedlot diets on
           nutrient digestibility, rumen fermentation, bacterial communities and
           plasma metabolites in beef steers
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): M.L. He , J. Long , Y. Wang , G. Penner , T.A. McAllister
      This study investigated the effect of substituting barley grain with wheat on rumen fermentation, bacterial communities, nutrient digestibility and plasma metabolites in finishing feedlots steers. The experiment was designed as a replicated 4×4 Latin square with 8 rumen cannulated steers (742±44kg) fed diets in which wheat was substituted for 0, 30%, 60% or 89% of barley grain dry matter (DM). All grains were dry-rolled to a processing index (PI) of 80% expressed as a percentage of volume weight of processed grain divided by the volume weight of unprocessed grain. The remaining dietary ingredients consisted of 6% barley silage and 5% supplement. Duration of pH below 5.8 linearly increased (P=0.04) with increasing levels of wheat, whereas average, minimum and maximum pH as well as the time and area under pH 5.5 (P=0.08) and 5.2 (P=0.18) did not differ among diets. Likewise, volatile fatty acids (VFA) profiles, concentrations of VFA, ammonia, numbers of protozoa and total tract digestibility of nutrients were unaffected (P>0.05) by this substitution. Increasing levels of wheat linearly increased copy numbers of 16S rRNA for total bacteria (P=0.01) and Ruminococcus amylophilus (P=0.04) per g of rumen contents. Inclusion of wheat in the diet linearly reduced plasma albumin (P=0.03) and urea nitrogen (P=0.01) concentrations, but did not affect (P>0.05) other major plasma metabolites. In conclusion, replacing barley grain with wheat in the diets of feedlot steers had little negative impact on nutrient digestibility or rumen fermentation, however, it increased the daily duration that rumen pH remained below 5.8. These data suggest that there is little difference in the ruminal fermentation or digestibility of barley vs wheat if both grains are processed to a similar degree.


      PubDate: 2015-05-18T14:36:23Z
       
  • Influence of dietary fat sources and lysolecithin on growth performance,
           visceral organ size, and histological intestinal alteration in broiler
           chickens
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): D. Khonyoung , K. Yamauchi , K. Suzuki
      The aim of this study was to investigate the influence of dietary fat sources and lysolecithin on growth performance, visceral organ size, and histological intestinal alterations in broiler chickens. Ninety-six 7-d-old male broiler chickens were assigned to 8 treatments in a 2×4 factorial arrangement of treatments with 2 levels of lysolecithin (0 and 145mg/kg) and 4 different fat sources [poultry fat (PF), yellow grease from Kagoshima (YG1), yellow grease from Kashima (YG2), and yellow grease from Hachinohe (YG3)]. Each treatment had 4 replicates of 3 broiler chickens per cage until 49d of age. There was no difference in BW gain due to fat sources, lysolecithin, or lysolecithin×fat source interaction throughout the experiment. By feeding lysolecithin, feed efficiency increased (P<0.05) during the growth period of 7 to 21d of age, and the weights of the duodenum, ileum, and total intestine decreased (P<0.05). Intestinal villus height, villus area, and cell area were not different among treatment groups, except that ileal villus height tended to decrease and ileal cell area tended to increase (P=0.077) by feeding lysolecithin. Increased duodenal cell mitosis and decreased jejunal tunica muscularis thickness were observed (P<0.05) by feeding lysolecithin. Furthermore, on the villus apical surface, more protuberated cells, cell clusters, and deeper cells at the sites of recently exfoliated cells were observed by feeding lysolecithin. However, the protuberant cells were not different among treatment groups. The Integrated Fluorescence Density Values of Anti-Cluster of Differentiation 36 reaction in the jejunum were significantly greater in the lysolecithin-fed groups, except YG2. These results indicate that feeding lysolecithin improves feed efficiency during 7 to 21d of age regardless of the fat type, and causes epithelial hypertrophy.


      PubDate: 2015-05-18T14:36:23Z
       
  • The effects of previous dietary Lys concentration on subsequent growth
           performance of two different pig genotypes
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): A.E. Taylor , S. Jagger , P. Toplis , I.J. Wellock , H.M. Miller
      The aims of this study were to determine whether Lys restriction immediately after weaning could be compensated for when pigs were switched to a high-Lys diet, and to determine whether this may be influenced by genotype. The experiment was a 2×2 factorial arrangement of diets and genotypes with 8 replicate pens per treatment and 8 or 9 mixed sex pigs per pen. Pigs received either a high- (Control; 17.5g/kg of Lys) or a low-Lys (WR; 8.0g/kg of Lys) diet during the first 3 week post-weaning followed by a high-Lys diet (15.5 and 12.0g/kg of Lys during the grower and finisher phases, respectively) to facilitate compensation until slaughter (approximately 101.2 ± 4.9kg). Two hundred and sixty four pigs [132 Hampshire sire×(Large White×Landrace) dam and 132 Large White sire×(Large White× Landrace) dam] were used and are referred to as Hampshire pigs and Large White pigs. Blood samples were collected from 2 selected pigs per pen at 6, 9, and, 15 week of age for blood urea nitrogen (BUN), non-esterified fatty acids (NEFA), and leptin analysis. Throughout the weaner phase, Control pigs gained more (105±1g/d) than WR pigs (P<0.001). However, once pigs were switched to a high-Lys diet, WR pigs gained more (44±9kg/d) than Control pigs and utilised their feed more efficiently (P<0.001), and thus compensatory growth was observed. Pigs of both genotypes performed similarly throughout the weaner stage when fed the low-Lys diet, however, when fed the high-Lys diet, Hampshire pigs had a greater rate of gain compared to Large White pigs (308 vs. 296±8g/d). Throughout the experiment, Hampshire pigs ate more feed (P<0.001), gained more (P<0.001), and had a greater Lys intake (P<0.001) compared to Large White pigs. Lean meat percentage at slaughter was greater for the Large White pigs compared to Hampshire pigs (P<0.05). At 6 week of age NEFA concentrations were greater for Control pigs compared to WR pigs (P<0.05). Hampshire pigs on the WR treatment had lower BUN levels during the weaner period compared to Hampshire pigs on the Control treatment (P<0.10). In conclusion compensatory growth was observed in both genotypes. The fact that Hampshire pigs grew faster when fed a non-limiting diet but grew at a similar rate compared to Large White pigs when fed a limiting Lys diet indicates that limiting dietary Lys level rather than genotype determined growth performance.


      PubDate: 2015-05-18T14:36:23Z
       
  • Supplemental dietary iron glycine modifies growth, immune function, and
           antioxidant enzyme activities in broiler chickens
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Jian Sun , Dasen Liu , Rubin Shi
      The objective of this study was to evaluate the effects of iron glycine (Fe-Gly) on growth, immune function, and serum antioxidant enzyme activities in broiler chickens. A total of 480 1-d-old broiler chickens [average body weight (BW), 45.9±0.5g] were randomly allotted to 8 dietary treatments with 6 replicate pens and 10 broiler chickens per replicate pen. The control treatment contained 160mg Fe/kg diet from FeSO4, while 7 other treatments consisted of 40, 60, 80, 100, 120, 140, and 160mg Fe/kg diet from Fe-Gly. After a 21-d-feeding period, there were increasing responses to the addition of 40–160mg Fe/kg from Fe-Gly, with the greatest ADG (quadratic, P<0.05) and ADFI (linear and quadratic, P<0.05) observed in broiler chickens fed with 100mg Fe/kg. The weight of thymus gland increased (linear and quadratic, P<0.05) with the increasing levels of Fe as Fe-Gly, and it was greater with 160mg Fe/kg from Fe-Gly compared with the control (P<0.05). Serum catalase (CAT), xanthine oxidase (XOD), and superoxide dismutase (SOD) increased as addition of Fe from Fe-Gly increased from 40 to 160mg /kg (linear, P<0.05), and the SOD activity was greater in broiler chickens fed the diet containing 160mg of Fe as Fe-Gly compared with those fed the control diet (P<0.05). The divalent metal transporter 1 (DMT1) mRNA expression was decreased with the increase of Fe as Fe-Gly in diets (linear and quadratic, P<0.05), and it was lower in broiler chicken fed the diet with 160mg/kg Fe as Fe-Gly compared with those fed the control diet with FeSO4 (P<0.05). This study indicated that addition of Fe-Gly could obviously modify antioxidant status of broiler chickens, and moreover, improve growth performance and immune function partially.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of different rearing systems on growth performance, nutrients
           digestibility, digestive organ weight, carcass traits, and energy
           utilization in male broiler chickens
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Y. Wang , Y.J. Ru , G.H. Liu , W.H. Chang , S. Zhang , H.J. Yan , A.J. Zheng , R.Y. Lou , Z.Y. Liu , H.Y. Cai
      A total of 600 male broiler chickens were randomly allocated to 1 of the following 3 rearing systems, multilayer cage rearing system (CRS), litter rearing system (LRS), and plastic flat net rearing system (NRS), to investigate the effects of different rearing systems on growth performance, nutrients digestibility, digestive organ weight, carcass traits, and energy utilization in male broiler chickens with 10 replicate cages or pens and 20 chickens per cage or pen. Growth performance was determined on d 0, 21, and 42, and all other response criteria were determined on d 21or 42. Weight gain and feed conversion ratios were not affected by 3 different rearing systems. However, feed intake in LRS treatment was lower (P<0.05) than the other 2 treatments during d 0 to 21.The apparent ileal digestibility (AID) of dry matter and N were not affected by different rearing systems, while CRS treatment had lower AID for energy than other 2 treatments at d 42 (P<0.05). Broiler chickens on LRS treatment had a heavier gizzard than other 2 treatments at both d 21 and 42 (P<0.05). Carcass yield, breast meat yield, breast weight, and thigh weight were unaffected by different rearing systems at both d 21 and 42. At d 42, thigh yield in broiler chickens on CRS treatment was greater than those on NRS treatment (P<0.05). Broiler chickens on CRS treatment had a lower abdominal fat than those on other 2 treatments at d 21 (P<0.05). However, it was found that the lowest and the greatest abdominal fat were observed with CRS and LRS treatments, respectively, at d 42 (P<0.05). Broiler chickens reared in LRS had lower apparent ileal digestible energy intake than those in CRS and on NRS during d 0 to 21 (P<0.05). Apparent ileal digestible energy (AIDE), net energy for production, energy retained as fat (RE f ) and protein (RE p ), efficiency (k) of AIDE use for total retention (kRE), lipid retention (kRE f ), and protein retention (kRE p ) did not differ among the treatment groups at any point during the experimental period. In conclusion, the results of the current study indicated that growth performance, energy retention (RE f and RE p ), and efficiencies of energy utilization (kRE, kRE f , and kRE p ) were >unaffected by different rearing systems. In addition, broiler chickens reared in CRS had lower AIDE than those reared in other 2 rearing systems during the later phase.


      PubDate: 2015-05-18T14:36:23Z
       
  • Discrepancies in porcine microbiota composition between in vivo
           measurements and in vitro fermentation with the modified Hohenheim Gas
           Test
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): E. Weiss , V. Rist , F. Rink , R. Mosenthin
      In vitro gas production methods are often used to evaluate the fermentation characteristics of pig diets or their ingredients by using porcine feces as microbial inocula. The aim of the present study was to assess, whether the microbial composition of the fermentation broth after in vitro fermentation still would be representative of pig feces. Microbial composition of feces of pigs fed a standard diet was compared with microbial composition of the fermentation broth after fermenting the same pig diet using the modified Hohenheim Gas Test. Using quantitative real-time PCR, feces and fermentation broth were analyzed for total bacteria, Lactobacillus spp., Bifidobacterium spp., Enterobacteriaceae, Bacteroides–Prevotella–Porphyromonas, Clostridium Cluster IV, and Clostridium Cluster XIVa. With the exception of Clostridium Cluster XIVa, 16S copy numbers of total bacteria (P=0.020), Lactobacillus spp. (P<0.001), Enterobacteriaceae (P<0.003), Bacteroides–Prevotella–Porphyromonas (P=0.028), and Clostridium Cluster IV (P<0.001) were greater in porcine feces, while Bifidobacterium spp. was lower (P=0.001), when compared with the fermentation broth after in vitro fermentation. In conclusion, 16S copy numbers present in fermentation broth after in vitro fermentation using the modified Hohenheim Gas Test may not necessarily coincide with those determined in pigs׳ fresh feces for all bacterial groups assessed. These findings support the need for validating in vitro with in vivo studies.


      PubDate: 2015-05-18T14:36:23Z
       
  • Does the presence of umbilical outpouchings affect the behaviour of pigs
           during the day of slaughter?
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Sarah-Lina Aa. Schild , Pia Brandt , Tine Rousing , Mette S. Herskin
      The aim of the present study was to examine behavioural and clinical consequences of the presence of umbilical outpouchings (UOs) in pigs during the day of slaughter, in order to establish new knowledge of relevance for the assessment of fitness for transport of these animals. Based on the Danish national guidelines involving the diameter of the UOs, considerable attention was paid to this measure. A total of 29 pairs of pigs from seven different commercial herds with standard pig housing, involving pens of partially slatted flooring, were included in this observational study. Focal animals were selected in the home pen on the day before transport to the abattoir and subjected to a clinical evaluation involving scores of skin lesions in healthy control animals and pigs with UOs. On the day of slaughter, video recordings were conducted during unloading at the abattoir and in the race to the stunner. For both pigs with UOs and control pigs, the skin lesion score increased over the day of slaughter. No significant differences between pigs with UOs and controls were found for any of the measures considered relevant for the fitness for transport.


      PubDate: 2015-05-18T14:36:23Z
       
  • Association of natural (auto-) antibodies in young gilts with
           osteochondrosis at slaughter
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): D.B. de Koning , E.P.C.W. Damen , M.G.B. Nieuwland , E.M. van Grevenhof , W. Hazeleger , B. Kemp , H.K. Parmentier
      Osteochondrosis (OC) develops at a young age and has been associated with lameness and reduced longevity of sows. Early detection of OC is therefore beneficial for selection against OC. Possibly, immunological components within the blood may serve as an indicator for OC development and could therefore be used as a biomarker. Levels of naturally occurring (auto-) antibodies (N[A]Ab) have been associated with homeostatic imbalance and various forms of inflammation, and may have an association with OC. The aim of this study was to investigate possible associations between the presence and levels of N(A)Ab of the IgM and IgG isotypes at an early age with OC in growing gilts at slaughter (24 weeks of age). Plasma samples were obtained from 212 Topigs 20 (Dutch Large White x Dutch Landrace) gilts at 6, 10, and 24 weeks of age and analyzed for N(A)Ab titers against 11 (auto-) antigens using ELISA. After slaughter, the elbow, hock, and knee joints were macroscopically examined for OC status. Due to low prevalence of OC in the elbow joint (5.4%), the elbow joint was not taken into account in analyses. Significant (P≤0.05) associations with OC in both the hock joint and at the animal level (all joints combined) were found for IgM titers against chondroitin sulfate A at 6 weeks of age (OR 1.4 and 1.5), actin at 6 weeks of age (OR 1.4 and 1.3), thyroglobulin at 24 weeks of age (OR 1.5 and 1.3), and IgG titers against insulin at 6 weeks of age (OR 1.7 and 1.4). Additionally, significant (P≤0.05) associations with OC were found at the knee joint for IgM titers against albumin at 6 weeks of age (OR 2.3), at the hock joint for IgM titers against keyhole limpet hemocyanin at 6 weeks of age (OR 1.4), and at the animal level for IgM titers against actin at 24 weeks of age (OR 1.3). This study indicated for the first time associations between the presence and levels of N(A)Ab at a young age and OC at 24 weeks of age in breeding gilts.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of space allocation and parity on selected physiological and
           behavioural measures of well-being and reproductive performance in
           group-housed gestating sows
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Alexandra L. Whittaker , Kate J. Plush , Robyn Terry , Paul E. Hughes , David J. Kennaway , William H.E.J. van Wettere
      The aim of this study was to evaluate the effects of parity and space allowance on selected measures indicative of welfare, and on reproductive parameters, in group-housed sows. Selected animals were at first parity or parity three or greater, and were housed with allocated space allowances per pig of 1.4 or 2.8m2. Welfare outcome measures included: injury and lameness scores, plasma cortisol levels, neutrophil:lymphocyte ratios and reproductive performance. These values were recorded at a range of timepoints in the first 24h after mixing, and at 28 days after the mixing event. In general there were few significant effects of space allowance and parity level on the measured outcomes. However, improved reproduction, as evidenced by increased litter size and born alive figures, was seen as a result of increased space allowance in older animals. A contrary response was observed in gilts. Cortisol responses also indicated that there was a rapid habituation to the stress of mixing with levels returning to baseline within 24h. Cortisol levels remained low in older animals but unexpectedly showed a peak at 28 days in gilts. It is postulated that this may have arisen as a result of handling events associated with pregnancy testing. Our results suggest that at least at the chosen stocking densities, parity and space allocation have minimal effect on a number of commonly-used welfare measures.


      PubDate: 2015-05-18T14:36:23Z
       
  • Potential strategies of adaptation of mixed sheep-crop systems to changes
           in the economic environment in a Mediterranean mountain area
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): A.M. Olaizola , F. Ameen , E. Manrique
      In the Mediterranean regions, sheep farming systems are mostly located in less favoured areas and play a multifunctional role. Nevertheless, those systems have experienced a strong decline in the last decades, which has led to the abandonment of pasturelands and other socio-economic changes in some areas. Traditionally, sheep farming systems are associated to cereal crops and remain common in Mediterranean areas. The objectives of this study were (i) to evaluate the possible adaptation strategies for sheep-crop mixed systems in the Sierra and Cañones de Guara Natural Park (SCGNP) to changes in the agricultural policy measures and the labour market, and (ii) to approximate the value of grazing as an environmental function provided by these systems. Four types of mixed sheep-crop systems (MSCS) in SCGNP were established in a previous typology (Bernués et al., 2004. Cahiers Options Méditerranéennes 62, 195–198). In 2007–2008, a survey was carried out 46 farms (95% of sheep farms that used the Natural Park). From that information, four farms were selected, one for each type of MSCS to be modeled. Mixed linear programming models were developed. Five socio-economic scenarios were simulated depending on CAP conditions, availability of labour (farmer pluriactivity), and prioritization of grazing. Under the scenario of total decoupling of the CAP subsidies, the best Gross Margin was obtained by the mixed farm with large flock and oriented to cereal cultivation (MSCS3) and the mixed farm with a large flock (MSCS2), but labour productivity was highest in the most cereal-oriented mixed systems. Off-farm work was economically profitable in the majority of the MSCS, which may lead to a decrease in the livestock farming activity and changes in land use with a reduction in the area leased for grazing, and in the area used for the cultivation of lucerne and sainfoin. Under current conditions (total decoupling of subsidies, high cereal prices), the total production of barley was sold, i.e., not fed to livestock. In contrast, in the scenarios of no subsidies, maximization of the use of pastures, or reduction of barley price, the farmhouse barley consumption for feeding livestock increased. The most livestock oriented farm (MSCS2) was the type of mixed farming system that should receive the least economic compensation for grazing as an environmental function provided by this farm and the most cereal-oriented systems required the most compensation. Nevertheless, the MSCS studied were highly diverse in the distribution of land use and trade-offs exist among the environmental functions performed by them.


      PubDate: 2015-05-18T14:36:23Z
       
  • Cow management modulates gene expression in the mammary gland, a possible
           epigenetics role
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): Isabel Gigli , Daniel Omar Maizon
      Epigenetics, the study of the change in gene expression that occurs without alteration in DNA sequences, leads to modifications that can be passed on by mitosis. It has been known for many years that cow management during lactation affects milk production. Now it is clear that some factors influence milk production even before the onset of lactation (during the dry period). In the last decade, a greater understanding of the molecular events that occur in the mammary epithelial cells provided an explanation for these changes. Gene expression in the mammary gland shows a temporal–spatial regulation. This is achieved by different regulatory layers of gene expression involving, for example, chromatin condensation and the combinations of several hormones and transcription factors. The goal of this review is to bring together an update of studies on gene expression in the mammary gland, highlighting the possible influence of cow management on epigenetic mechanisms. The impacts of milking frequency, mastitis, photoperiod and heat stress on gene expression and their effects on milk production were discussed. Understanding how the mammary gland responds to external factors will help to design better strategies and technologies to enhance milk production.
      Graphical abstract image

      PubDate: 2015-05-18T14:36:23Z
       
  • Milk fatty acid composition and mammary lipogenic genes expression in
           bovine cloned and control cattle
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): L. Bernard , C. Richard , V. Gelin , C. Leroux , Y. Heyman
      In order to understand the effect of nuclear transfer technology on the physiology of lactation and milk fatty acid composition in dairy cattle (Holstein breed), the present study compares the milk yield and composition from bovine somatic cell cloned (n=5) and control animals (n=5) at 180 days in milk (DIM) maintained together under the same conditions. All cows were offered the same total mixed ration ad libitum. At 180 DIM, the cloned had a higher body weight (BW; P<0.01) compared with control animals, whereas comparable body condition score (BCS) was observed among the 2 groups. The cloned cows had a lower milk yield and milk protein and lactose yields (P<0.05) and had a tendency (P=0.08) for a lower milk fat yield. Conversely, no differences in milk fat, protein and lactose concentrations were observed in cloned compared with control animals. Similar milk fatty acid (FA) concentrations were observed in cloned and control cows except for two minor FA, cis-9 C10:1 and C17:0 (P<0.05) that were higher in the cloned. The milk fat cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, cis-9 C18:1/C18:0, cis-9, trans-11 C18:2/trans-11 C18:1 concentrations ratios were not different in cloned and control. The milk medium-(C10–C16) and long-(∑C18) chain FA yields were lower (P<0.05) in cloned compared with control animals. The mRNA abundance of genes encoding for SCD1, SCD5, ACACA and FABP3 genes in mammary tissue was similar (P>0.05) in cloned and non-cloned animals. Conversely, cloned animals had a lower (P<0.05) mRNA abundance of LPL and a tendency (P<0.10) for lower mRNA abundance of FASN and CD36 genes compared with control. The absence of major differences of milk constituent concentrations, milk FA composition and of the SCD desaturation indices observed between cloned and conventional animals suggest a comparable nutritional quality of milk for these animals. The noticed differences in milk long chain-FA yields were consistent with modulation of mammary lipogenic pathway as suggested by lower mRNA abundance of LPL gene in cloned compared with control. Otherwise, differences in the partitioning of nutrients between the mammary gland and other tissues cannot be excluded as suggested by the higher BW and lower milk yield observed in cloned. Altogether, these observations may be attributed to different genetic background and/or to epigenetic modifications due to the nuclear transfer technology that may affect the growth and the physiological adaptation to lactation and impact the dairy performances. Further investigations are required to identify the mechanisms underlying these differences.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of supplementation of flax meal and flax oil on mammary gene
           expression and activity of antioxidant enzymes in mammary tissue, plasma
           and erythrocytes of dairy cows
    • Abstract: Publication date: June 2015
      Source:Livestock Science, Volume 176
      Author(s): L.S. Lima , M.F. Palin , G.T. Santos , C. Benchaar , H.V. Petit
      The effects of antioxidants from flax meal (FM) and abomasal infusion of flax oil (FO) on the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase (GPX)) in blood and mammary tissue and the mRNA abundance of antioxidant and lipogenic-related genes in mammary tissue of dairy cows were determined. Eight ruminally fistulated lactating Holstein cows were assigned to a double 4×4 Latin square design with a 2×2 factorial arrangement of treatments: (1) control diet with no FM (CON); (2) diet containing 124g/kg FM (FMD) in the dry matter (DM); (3) CON and 250g FO/d infused in the abomasum; (4) FMD and 250g FO/d infused in the abomasum. Catalase activity in erythrocytes tended to increase when cows were fed FMD. Abomasal infusion of FO had no effect on activity and gene expression of antioxidant enzymes and gene expression of lipogenic-genes in mammary tissue, except for an increase in GPX1 expression in the absence of FM. The results suggest that feeding 124g/kg FM and infusing 250g of FO/d in the abomasum of dairy cows does not induce significant changes in the activity of antioxidant enzymes in blood and mammary tissue, and expression of antioxidant and lipogenic-genes in mammary tissue. However, more studies are required to determine any beneficial effects of natural antioxidants such as FM on the oxidative status of cows supplemented with polyunsaturated fatty acids, which could lead to feeding strategies to prevent diseases affecting the health status of dairy cattle.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of organic, inorganic, and nano-Se on growth performance,
           antioxidant capacity, cellular and humoral immune responses in broiler
           chickens exposed to oxidative stress
    • Abstract: Publication date: Available online 16 May 2015
      Source:Livestock Science
      Author(s): A Boostani , Sadeghi , SN Mousavi , M Chamani , N Kashan
      The present study was designed to compare different sources of Selenium (Se) on growth performance, antioxidant capacity, cellular and humoral immune responses of male broilers subjected to oxidative stress. In a completely randomized design, 320 broilers were assigned to a 2×4 factorial arrangement comprising 4 replicates of 10 birds per each. Broilers were divided in 2 groups for oxidative stress; 1 as control (no oxidative stress) and the other 1 was peritoneally received tert-butyl hydro peroxide (tert-BHP) as oxidative stress inducer. Birds in each level of oxidative stress were received either supplemented Se diet (CON) or diets supplemented with 0.3mg/kg nano-Se (NAN), organic Se (ORG), and inorganic Se (INO). Sources of Se, oxidative stress, and their interaction had no effect on the feed intake, daily body gain and feed conversion ratio (P>0.05). Se supplementation increased glutathione (GSH) content and glutathione peroxidase (GSH-Px) activity compared to the control group (P<0.05). However, birds in oxidative stress had lower glutathione (GSH) content and GSH-Px activity as compared to non-stressed ones. Se supplemented groups had lower malondialdehyde (MDA) concentrations compared to the control groups (P<0.05), and birds on oxidative stress conditions had higher MDA level as compared to non-stressed birds. The IgM and IgG levels were significantly increased in NAN group compared to CON and other experimental groups (P<0.05). The highest serum IgG and IgM concentrations were recorded for non-stressed birds received nano-selenium and organic selenium. Birds in oxidative groups had lower foot swelling response value as compared to non-oxidative groups only at 24h following the phytohemagglutinin-P (PHA-P) injection (P<0.05). The oxidative condition decreased the lymphoid organs weight compared to non-oxidative condition. These increases in antioxidant enzyme activities have been considered as a protective response against oxidative stress. It was concluded that supplementation of diet with 0.30mg/kg of different sources of Se increased the antioxidative capacity of broiler chicken under oxidative stress and nano-Se effect was higher than organic or inorganic source.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of a supplement containing multiple types of gluconeogenic
           precursors on production and metabolism in Holstein bull calves during
           heat stress
    • Abstract: Publication date: Available online 16 May 2015
      Source:Livestock Science
      Author(s): M. Hossein Yazdi , H. Amanlou , H.R. Mirzaei-Alamouti , M.T. Harkinezhad , A. Nabipour , E. Mahjoubi , N. Aghaziarati , G.R. Noori , L.H. Baumgard
      Glucose appears to be a preferred systemic fuel during heat stress (HS) in a variety of species. Increasing the dietary grain content can enhance the post-absorptive carbohydrate status, but providing excessive fermentable starch can cause rumen disorders and this is especially true during HS. Current study objectives were to evaluate the effects of a glycerol based supplemental product on growth and metabolic variables in Holstein bull calves during controlled HS. Before the start of the experiment, bull calves (n=14; 163.6±30.1kg body weight) were subjected to thermal neutral conditions [26.5±3.4°C and a temperature-humidity index (THI) of 70.4±2.8] for 7 d (period 1; P1). During this period, productive parameters as well as blood metabolites were measured and used as covariates for the subsequent HS period. Following P1, a cyclical HS pattern was implemented for 21 d (P2) where daily ambient temperatures ranged from 29.1 to 39.7°C and the THI was>74 for 24h/d and >83 for at least 14h/d. During P2, half of the HS calves (n=7) received a control diet (CON) and the other half received the control diet supplemented with a product (300g/d) containing gluconeogenic precursors (GLU). Throughout each period respiration rate, rectal temperature and skin temperature at the shoulder and rump were recorded at 0600, 1100 and 1500h daily. Blood samples were obtained prior to and 4h post the a.m. feeding during both periods. Although HS markedly reduced DMI (18%) and growth as expected, supplemental GLU did not affect body weight gain. Supplemental GLU decreased the shoulder temperature at 0600 and 1500h (P<0.01), and decreased respiratory rate at 1500h (P<0.02). Feeding GLU did not affect blood urea nitrogen (BUN), glucose or nonesterified fatty acids (NEFA) concentrations, but increased circulating insulin prior to the a.m. feeding (P<0.03) and this demonstrates that GLU was effective at enhancing the post-absorptive carbohydrate status. Our results suggest that feeding supplemental GLU improves some body temperature indices but did not enhance growth performance in Holstein bull calves during HS.


      PubDate: 2015-05-18T14:36:23Z
       
  • Occlusal angles of equine cheek teeth
    • Abstract: Publication date: Available online 15 May 2015
      Source:Livestock Science
      Author(s): Laura Listmann , Patricia Schrock , Klaus Failing , Carsten Staszyk
      The aim of this work was to determine occlusal cheek tooth angles in horses. The complex spatial shape of the equine skull hampers exact measurements of the occlusal cheek tooth angles in anatomical specimens and as well in living horses. Therefore a method was developed to perform measurements by using detailed 3D-reconstructions of equine skulls. 3D-models were constructed from CT-datasets by manual identification of relevant anatomical structures and by use of a computer software. Within 3D-skulls anatomical landmarks were identified and reference lines and planes were determined. Subsequently, occlusal angles of check teeth were measured in relation to the median plane. Results for mean values of cheek teeth angles ranged from 15.1° to 20.2°. Angles increased stepwise from rostral to caudal. Considering the total amount of data (20 horses with permanent dentition), there were no significant differences between the jaw quadrants when teeth in same Triadan positions were compared. However, in individuals there was a significant difference between the left and right side of the jaw. Angles of antagonistic teeth correlate with each other. The results are expected to provide a substantial basis for preventive and therapeutic treatments as well as for further biomechanical studies about equine mastication.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effect of High stocking density on performance, egg quality, and plasma
           and yolk antioxidant capacity in laying hens supplemented with organic
           chromium and vitamin C
    • Abstract: Publication date: Available online 11 May 2015
      Source:Livestock Science
      Author(s): R. Jahanian , E. Mirfendereski
      This study was conducted to investigate the effects of dietary supplementation of chromium-methionine (CrMet) and vitamin C on performance, egg quality measurements, and plasma antioxidant capacity in laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 laying hens, 26wk of age, were used in a 2×2×3 factorial arrangement of treatments consisting of 2 cage densities [5 or 7 hens/cage (40×45cm)], 2 supplemental vitamin C levels (0 and 500mg/kg as L-ascorbic acid), and 3 supplemental Cr levels (0, 500, and 1,000μg/kg as CrMet) with 5 replicate cages per treatment. The hens were kept in wire-floor cages in an environmentally-controlled room. After a 2-wk adaptation, the 70-d study was initiated and it was divided into two 35-d periods (28 to 33 and 33 to 38wk of age). Results showed that although subjecting hens to high stocking density had no effect on egg production percentage during 28 to 33wk of age, it decreased (P=0.031) during the 33 to 38wk of age, resulting in a marked reduction (P=0.038) in egg mass. Dietary Cr supplementation (500 and 1,000μg/kg) increased (P<0.01) egg production and egg mass during both 35-d periods, and improved (P=0.005) feed conversion ratio (FCR) during the first 35-d period. There was a stocking density×vitamin C interaction (P=0.018) for FCR values during the first 35-d period, so that supplemental vitamin C improved FCR to a greater extent in high stocking density-challenged hens. Dietary CrMet supplementation (500 and 1,000μg/kg) increased (P=0.001) feed intake during the second 35-d period. Shell thickness was greater (P=0.015) in hens under high stocking density challenge during the second 35-d period. Subjecting hens to high stocking density decreased (P=0.007) plasma vitamin C concentration, while plasma vitamin C level was increased (P<0.05) as the result of dietary supplementation of vitamin C. Dietary supplementation of CrMet (500 and 1,000μg/kg) increased plasma vitamin C level only in high stocking density-challenged hens, resulting in a stocking density×Cr interaction (P=0.039). Although high stocking density increased (P<0.05) plasma and yolk concentrations of malondialdehyde (MDA), supplemental vitamin C decreased (P<0.05) plasma and yolk MDA contents. Similarly, dietary inclusion of CrMet (500 and 1,000μg/kg) decreased (P=0.046) plasma MDA level. The present findings indicate that dietary CrMet supplementation could increase antioxidant capacity in stressed hens, which improve production performance of laying hens.


      PubDate: 2015-05-18T14:36:23Z
       
  • Impact of the temperament of Nellore cows on the quality of handling and
           pregnancy rates in fixed-time artificial insemination
    • Abstract: Publication date: Available online 8 May 2015
      Source:Livestock Science
      Author(s): Paola M. Rueda , Aline C. Sant’Anna , Tiago S. Valente , Mateus J.R. Paranhos da Costa
      The aim of this study was to evaluate the effects of temperament on the quality and efficiency of handling and on the pregnancy rate of Nellore cows submitted to a fixed time artificial insemination (FTAI) protocol. Temperament and handling procedures were simultaneously assessed in 798 Nellore cows on the first (d0), ninth (d9) and 11th days (d11) of the FTAI protocol, using the flight speed (FS) and crush score (CS) tests. During the insemination process performed on d11 of the FTAI protocol, the following handling indicators were recorded: rough or overly aggressive handling of the cows by stockpersons (AGGRESSION), accidents (ACCIDENT), time to inseminate (TIME), and the degree of dirtiness on cows’ perineal region (DIRTINESS). There was a significant effect of CS on TIME (P=0.013) and DIRTINESS (P=0.004), while FS tended to affect TIME (P=0.06) and the likelihood of AGGRESSION (P=0.07). Cows subjected to aggressive handling and/or accidents had a greater FS mean than cows that did not face such aversive situations (2.07±1.18 vs. 1.74±0.75m/s, P=0.0003). The chance of pregnancy (expressed in odds ratio) was greater in cows with low FS (OR=1.48) than in cows with high FS (defined as the reference class, with OR=1) (χ2=3.73, P=0.05), and the low FS group had 10% more pregnant cows than the high FS group (with 52.59% vs. 42.62% pregnant cows, respectively). Pregnant cows had significantly lower FS means relative to non-pregnant cows on d0 (1.79 vs. 2.10m/s, P<0.001), d9 (1.79m/s vs. 1.67m/s, P=0.038) and d11 (1.90m/s vs. 1.70m/s, P=0.004). We conclude that excitable temperament has an effect on the quality and efficiency of handling during FTAI, by increasing the time required for insemination, the dirtiness on cows’ perineal region and the likelihood of aggressive actions by stockpersons. Also, cattle temperament measured by FS reduces the chance of pregnancy in Nellore beef cows.


      PubDate: 2015-05-18T14:36:23Z
       
  • Lipid mobilization assessment in transition dairy cattle using ultrasound
           image biomarkers
    • Abstract: Publication date: Available online 7 May 2015
      Source:Livestock Science
      Author(s): C. Strieder-Barboza , A. Zondlak , J. Kayitsinga , A.F.A. Pires , G.A. Contreras
      Excessive lipid mobilization during the transition period of dairy cows predisposes animals to higher disease incidence and reduces lactation performance. Plasma non-esterified fatty acids (NEFA) are used as a marker of lipid mobilization intensity to monitor transition cow management and as a disease risk predictor. NEFA evaluation can be complemented by continuous monitoring of adipose tissue depth reductions during the transition period using ultrasound images of the retroperitoneal (RPAT) and subcutaneous adipose tissue (BFAT) depots. These image biomarkers are easily obtainable and their real time nature offers an important advantage that could help improve transition cow health programs. The objective of this study was to evaluate the use of both RPAT and BFAT ultrasound measurements as quantitative image biomarkers and its association with plasma NEFA. A longitudinal cohort study evaluated adipose image biomarkers in 44 Holstein cows in a commercial dairy herd. Ultrasound examination and blood samples collection were performed at 4 (dry) and 2–3 (close-up) weeks before expected calving date, and at 1 (calving) and 4 (lactation) weeks after parturition. Both RPAT and BFAT depth measurements were significantly lower at parturition and at the lactation samples compared to pre-calving measures and were negatively associated with plasma NEFA. Only BFAT predicted minimum concentrations of plasma NEFA before and after calving. The use BFAT as an image biomarker of lipid mobilization and its risk predictive value in other herds with different management styles requires further investigation.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of a multi-strain probiotics against aflatoxicosis in growing
           Japanese quails
    • Abstract: Publication date: Available online 6 May 2015
      Source:Livestock Science
      Author(s): F. Bagherzadeh Kasmani , M. Mehri
      An experiment was conducted to determine the effects of a multi-strain probiotics (PRO) on growth performance and immune status of growing Japanese quails fed aflatoxin B1 (AFB1). A total of 320 quail chicks were assigned to 4 treatments, control (basal diet), AFB1 (basal diet+2.5mg AFB1/kg), PRO (basal diet+150mg PRO/kg), and AFB1+PRO (basal diet+2.5mg AFB1 and 150mg PRO/kg) with 4 replicate pens and 20 quails per pen. The quail chicks had free access to water and experimental diets from 7 to 35 d of age, and feed intake (FI) and body weight gain (BWG) were measured weekly. Overall feed intake and BWG were reduced in AFB1 treatment (P<0.05), but feeding probiotics improved those criteria in quails received dietary AFB1 (P<0.05). During 7–35d of age, AFB1 increased FCR while the PRO supplementation decreased FCR in quails fed AFB1 diet (P<0.05). Moreover, FCR in AFB1+PRO treatment was better than PRO treatment (P<0.05). The most hypertrophy in internal organs (e.g., liver and spleen) and suppressed growth in testes and bursa of Fabricius were observed in AFB1 group but feeding PRO improved the status of these organs (P<0.05). The humoral (e.g., antibody response against sheep red blood cell antigen) and cellular responses (e.g., skin thickness against 2,4-Dinitro 1-chlorobenzene) were suppressed in quails fed AFB1 but feeding PRO boosted those immune systems (P<0.05). The use of AFB1 in diet invariably increased the levels of aspartate transaminase, alanine aminotransferase, and alkaline phosphatase in the sera of Japanese quails (P<0.05). The opposite effect was observed for aforementioned enzymes because of PRO in the diets. This study showed that under aflatoxicosis, the use of dietary multi-strain probiotics could improve the growth performance and immunocompetence in growing Japanese quails.


      PubDate: 2015-05-18T14:36:23Z
       
  • Optimal timing of boar exposure relative to parturition for stimulation of
           lactation oestrus
    • Abstract: Publication date: Available online 5 May 2015
      Source:Livestock Science
      Author(s): R. Terry , Karen L. Kind , Alice C. Weaver , Paul E. Hughes , William H.E.J. van Wettere
      This study evaluated the effect of full physical boar exposure at different stages of lactation on the incidence of lactation oestrus in both primiparous and multiparous sows. A total of 38 primiparous (PP) and 80 multiparous (MP) sows (parity 2–6; 3.1±0.18) of Large White×Landrace genetics were individually housed in conventional farrowing crates from 1 week before expected farrowing until weaning on day 27.5±0.08 post-parturition. The experiment was designed as a 2×4 factorial, incorporating the two sow parity groups, and boar exposure commencing on one of four days post-farrowing (days 10, 14 and 18 of lactation and weaning). The eight treatments were as follows: PP sows, boar exposure starting on day 10 (n=10), day 14 (n=9), day 18 (n=9) and weaning (n=10); MP sows boar exposure starting on day 10 (n=20), day 14 (n=20), day 18 (n=20) and weaning (n=20). According to treatment, sows were taken daily to a detection mating area where they received 20min of boar exposure and were artificially inseminated at the first observed oestrus. A significant effect of replicate on the incidence of lactation oestrus was found; specifically, the proportion of sows expressing a lactation oestrus was lower in replicate 4 (autumn) than in the other three replicates (winter/spring; 0.15 versus 0.51; P<0.01). In replicate 1–3, a significantly higher proportion of MP compared to PP sows experienced a lactation oestrus (0.63 versus 0.36; P<0.05). Lactation oestrus expression was lower for MP sows starting boar exposure on day 14 compared to day 18 post-partum (0.38 versus 0.79, respectively; P<0.05), but was similar for days 10 and 18 of lactation (0.69 versus 0.79, respectively; P<0.05). Commencing boar exposure on day 18 as opposed to day 10 post-partum significantly reduced the interval from boar exposure to lactation oestrus expression (4.5±0.8 versus 7.7±0.8 days, respectively; P<0.05). Therefore, full physical boar exposure stimulated a high proportion of lactation oestrus in multiparous sows; however, season impacted this expression, and first parity sows are less likely than multiparous sows to express a lactation oestrus. In conclusion, there appears to be no benefit in commencing boar exposure before day 18 post-partum to stimulate a lactation oestrus.


      PubDate: 2015-05-18T14:36:23Z
       
  • Prediction of the Ym factor for livestock from on-farm accessible data
    • Abstract: Publication date: Available online 2 May 2015
      Source:Livestock Science
      Author(s): G. Jaurena , J.M. Cantet , J.I. Arroquy , R.A. Palladino , M. Wawrzkiewicz , D. Colombatto
      Methane emission factor (Ym) is directly involved to calculate the worldwide livestock methane inventories, hence it is important to refine the estimation of this parameter for different livestock production systems. The purpose of this work was to generate refined mathematical models to predict CH4 emissions from an extensive compilated database at on-farm level and to compare them with different models already available in the literature. Methane emission predictive models (expressed as Ym, % gross energy intake; and methane production, CH 4 p, gan−1 d−1) where fitted taken into account the production system, the livestock type and the feed characteristics available at on-farm level within a reasonable uncertainty range. In order to develop the models, only easy available parameters were selected to fit new mathematical models. Hence, the full model included: ruminant types (beef cattle, dairy cattle, and sheep), fibre sources (fresh forage, conserved forage, and straw) and concentrate levels (DM basis) in the diet (Low, <35%; Intermediate, 35–65%; High, >65%). Full models were assessed by the Bayesian Information Criterion (BIC) and terms that did not reach significance level (P≤0.05) were dropped from the model. Furthermore, predicted results were assessed through correlation and regression analyses considering the model significance. Models developed in this study were compared by the degree of adjustment of a simple regression. Additive and technique terms were initially dropped from the full model used to predict Ym because they did not have effect in the prediction (P>0.10). Therefore, the final equation for Model 1 was: Ym(a)=Intercept−0.243(±0.051)×DMI (kgd−1)+5.9×10−3(±1.17×10−3)×NDF (gkg−1 DM−1)+5.7×10−3(±1.63×10−3)×DMD (gkg−1 MS−1) (BIC=559). All terms of this model, intercept factor (type of cattle×source of fibre×level of concentrate), DMI, NDF, and DMD were significant (P<0.0001). DMI was the term with the greatest weight in the model. The predicted Ym value decreased about 0.243 percentage units (P<0.0001) per each additional kg in DMI. When the equation was compared with previous publicated models, our model showed a satisfactory degree of fitting. In conclusion, this new model improved the estimation of the Ym factor from beef and dairy production systems, using different forage quality characteristics from on-farm level to increase precision.


      PubDate: 2015-05-18T14:36:23Z
       
  • Growth performance, apparent nutrient digestibility, intestinal morphology
           and carcass traits of broiler chickens fed dry, wet and fermented-wet feed
           
    • Abstract: Publication date: Available online 2 May 2015
      Source:Livestock Science
      Author(s): O.S. Akinola , A.O. Onakomaiya , J.A. Agunbiade , A.O. Oso
      This study seeks to investigate the growth performance, intestinal morphology, carcass traits and apparent nutrient digestibility of broiler chickens fed with dry, wet and fermented-wet feed. Three experimental diets were formulated in this study. Diet 1 was dry mash feed. Diet 2 was wet mash feed in a 1:1.3 mix with water. Diet 3, was fermented-wet mash feed in a 1:1.3 mix with water which was fermented for 24h in sealed plastic polythene bags prior to feeding. A total of 192 two-weeks-old broilers (Marshal strain) were randomly assigned to the experimental diets in a completely randomized design (CRD). Each treatment group was replicated four times with 16 birds per replicate. Each dietary treatment was fed immediately to the birds after re-constitution. Fermentation of the feed reduced (P<0.05) the pH from 6.61 to 4.37. Birds fed fermented-wet and wet mash recorded higher (P<0.05) final live weight and weight gain. Feed intake and feed conversion ratio were not affected (P>0.05) by wet and fermented-wet fed birds compared to the dry fed birds. Mortality was not affected by dietary treatment imposed. Apparent organic matter digestibility was higher (P<0.05) in birds fed fermented-wet feed when compared to birds fed with dry and wet feed. Intestinal villus morphology and carcass measurement were not affected (P>0.05) by the treatment imposed. However, birds fed wet feed showed lower (P<0.05) gizzard weight when compared to birds fed fermented-wet feed. Birds fed with fermented-wet mash recorded higher (P<0.05) abdominal fat than those fed with dry mash. The results of this study indicated fermented-wet feeding improved apparent organic matter digestibility with a resultant improved growth performance of broiler chicken.


      PubDate: 2015-05-18T14:36:23Z
       
  • Editorial Board
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175




      PubDate: 2015-05-18T14:36:23Z
       
  • Genome-wide association study for somatic cell score in Argentinean dairy
           cattle
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): Juan P Nani , Maria A Raschia , Mario A Poli , Luis F Calvinho , Ariel F Amadio
      This study aimed to understand the genomic architecture of Argentinean dairy herds by measuring linkage disequilibrium (LD) and identifying loci associated with parameters calculated from somatic cell count (SCC). Phenotypic data consisted of 3530 SCC records from 544 Holstein and Holstein x Jersey cows owned by a single dairy company located in the Central dairy area of Argentina. SCC was recorded every 40 days. After quality control, genotypic data consisted in 38,872 single nucleotide polymorphisms (SNP). The squared correlation of the alleles at two loci (r 2) was computed for all SNP pairs on each chromosome. At marker distances less than 10kb the average r 2 was 0.40. Between 40 and 50kb the average r 2 was 0.25 and 0.18 for 100kb apart. Three different variables were calculated from the somatic cell score (SCS): the arithmetic mean (AM), the maximum value (MAX) and the arithmetic mean of the top 3 values (TOP3). Few significant SNP associations were found. As expected, polygenic traits such as SCC are influenced by multiple loci throughout the genome, each with a relatively small effect. AM on one side and TOP3 and MAX on the other, showed different SNP associated showing that they capture different aspects of mastitis response. AM was significantly associated with two SNP: ARS-BFGL-NGS-114608 (BTA1) and Hapmap60306-rs29023088 (BTA5). MAX and TOP3 were significantly associated with four SNP: ARS-BFGL-NGS-107594, ARS-BFGL-NGS-104220 (BTA10), BTA-43543-no-rs (BTA18) and ARS-BFGL-NGS-109705 (BTA26). MAX and TOP3 were equivalent phenotypic variables to be used in a GWAS. These results contribute to gain insight into the genomic regions influencing the SCC in Argentinean herds.


      PubDate: 2015-05-18T14:36:23Z
       
  • Body condition score of Nelore cows and its relation with mature size and
           gestation length
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): D.D. Silveira , F.R.P. Souza , C.C. Brauner , D.R. Ayres , F.A. Silveira , N.J.L. Dionello , A.A. Boligon
      The objective of this study was to evaluate the genetic variability of body condition score (BCS) in Nelore cows, and analyze its genetic correlations with mature weight (MW), mature height (MH) and gestation length (GL), in order to obtain information supporting the possible use of this score in breeding programs. The BCS was recorded on pregnancy diagnosis and ranged from 1 (very thin) to 5 (extremely fat). Adjusted means for MW, MH and GL according to the BCS classes were obtained using an univariate mixed model for each trait. Bayesian Inference using Gibbs Sampling was applied to estimate (co)variances components and genetic and phenotypic correlations, in two-trait analyses, considering a threshold animal model for BCS and a linear animal model for the other traits. Adjusted means for MW, MH and GL showed significant variation (p<0.0001) among BCS classes, indicating that cows with higher BCS have greater mature size, assessed by MW and MH measures, and longer GL than those with lower BCS. The BCS showed genetic variability, with posterior mean heritability of 0.23±0.05. Genetic correlations between the BCS with MW, MH and GL were 0.41±0.04; −0.06±0.03 and 0.10±0.02, respectively. Selection based on BCS should result in gain for body condition and, by indirect response, in changes in the same direction for cows MW. However, selection for BCS has little or no effect on MH and GL. So that BCS can effectively be used as a selection criterion of beef cows, further studies should be performed in order to obtain genetic associations with other economic traits.


      PubDate: 2015-05-18T14:36:23Z
       
  • Genomic–polygenic evaluation of multibreed Angus–Brahman
           cattle for postweaning ultrasound and weight traits with actual and
           imputed Illumina50k SNP genotypes
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): M.A. Elzo , M.G. Thomas , D.D. Johnson , C.A. Martinez , G.C. Lamb , D.O. Rae , J.G. Wasdin , J.D. Driver
      The objectives were to estimate additive genetic variance fractions for 4 postweaning ultrasound and weight traits explained by 46,839 actual and imputed SNP genotypes, to compare rankings of calf additive genetic predictions from genomic–polygenic (GP), genomic (G), and polygenic (P) models, and to assess trends for GP, G, and P predicted additive genetic values as functions of calf Brahman fractions in a multibreed Angus–Brahman population. Traits were postweaning ultrasound ribeye area (UREA), backfat thickness (UBF), and percent intramuscular fat (UPIMF), and weight (UW). Phenotypes and Illumina3k genotypes were from 812 bull, heifer, and steer calves housed at the Feed Efficiency Facility of the University of Florida from 2006 to 2010. Program Findhap2 was used to impute from 2899 Illumina3k SNP to 46,839 Illumina50k SNP using a reference population of 828 Brangus heifers. Fixed effects for all models were contemporary group (year-pen), age of dam, sex of calf, age of calf, Brahman fraction of calf, and heterozygosity of calf. Random effects were additive SNP (GP and G models), additive polygenic (GP and P models), and residual. Software GS3 was used to compute variance components and heritabilities, and additive genetic predictions. Additive genetic variance fractions explained by the 46,839 actual and imputed SNP were 0.17 for UREA, 0.32 for UBF, 0.25 for UPIMF, and 0.19 for UW. Heritabilities were 0.33 for UREA, 0.22 for UBF, 0.43 for UPIMF, and 0.54 for UW. These additive genetic variance fractions were 1.8, 1.0, 4.4, and 2.1 times greater and heritabilities were 1.0, 1.2, 1.0, and 1.2 times greater than those obtained for these 4 traits using only the 2899 Illumina3k SNP. Rank correlations between EBV from GP and P models were the highest (0.93 to 0.96), followed by those between EBV from GP and G models (0.81 to 0.94), and by those between EBV from G and P models (0.66 to 0.81). Regression coefficients of EVB on Brahman fraction were small for all traits and models indicating that animals of comparable EBV existed in all breed groups. Imputation from Illumina3k to 50k increased the explained fraction of additive SNP variance resulting in higher rank correlations between additive genetic predictions from G and GP, and from G and P models for all ultrasound traits in this Angus–Brahman multibreed population.


      PubDate: 2015-05-18T14:36:23Z
       
  • Genetic diversity and phylogeographic structure of sixteen Mediterranean
           chicken breeds assessed with microsatellites and mitochondrial DNA
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): S. Ceccobelli , P. Di Lorenzo , H. Lancioni , L.V. Monteagudo Ibáñez , M.T. Tejedor , C. Castellini , V. Landi , A. Martínez Martínez , J.V. Delgado Bermejo , J.L. Vega Pla , J.M. Leon Jurado , N. García , G. Attard , A. Grimal , S. Stojanovic , K. Kume , F. Panella , S. Weigend , E. Lasagna
      The genetic diversities and relationships among 16 local breeds of chicken originating from five countries (Italy, Spain, Serbia, Albania and Republic of Malta) within the Mediterranean basin were assessed by sequencing part of the mitochondrial DNA (mtDNA) D-loop region and by genotyping individuals at 27 autosomal microsatellite loci. The aim was to study the microevolution of chicken on the northern shores of the Mediterranean and to determine their present genetic status. A 506bp fragment of the mtDNA control region was sequenced in 160 individual DNA samples. The mtDNA sequence polymorphisms nomenclature that is normally used in these studies suggests that the Mediterranean chicken breeds under investigation are related to haplogroup E. A total of 465 blood samples were collected and utilised for microsatellite analysis. Six breeds (Ancona, Livornese Bianca—Italy; Pita Pinta Asturiana, Gallina de Sobrarbe—Spain; Albanian population—Albania; and the Maltese Black—Malta) showed significant high levels of inbreeding. About 22% of the total genetic variation observed was due to variability between populations. STRUCTURE analysis confirmed the breed variability result (F ST=0.22) also observed in the Neighbor-Net dendrogram. These results strongly allude that the 16 Mediterranean chicken breeds studied originated from three distinct maternal lineages and retain moderate levels of autosomal genetic diversity.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of concentrate supplementation on enteric methane emissions and
           milk production of grazing dairy cows
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): Camila Muñoz , Sara Hube , Jorge M. Morales , Tianhai Yan , Emilio M. Ungerfeld
      Although concentrate supplements in ruminant diets have been recognised as an effective enteric methane mitigation strategy, very few studies have examined the effects of concentrate supplementation on enteric methane emissions under grazing conditions. Twenty four multiparous Holstein Friesian cows were used in a crossover design study to investigate the effects of two concentrate feeding levels across two periods on enteric methane emissions and milk production of grazing dairy cows. Each period had a duration of four weeks (three weeks for diet adaptation and one week for measurements) and no interval in between them. Dietary treatments consisted of two concentrate feeding levels per cow (1 vs. 5kg; as-fed basis) offered daily in equal meals during milking. Enteric methane emissions from cows grazing perennial ryegrass pasture were measured during the final week of each period using the sulphur hexafluoride tracer technique. Milk yield and liveweight were determined daily during each methane measurement period, whereas milk composition and body condition score (BCS) were determined weekly. Daily herbage intake by individual cows during methane measurement weeks was estimated using an energy requirement model and animal records and diet composition. In period 1, cows receiving 5kg concentrate supplement were estimated to reduce herbage intake by 1.8kg DM/d compared to cows receiving 1kg of concentrate, whereas in period 2 cows receiving the 5kg concentrate supplementation were estimated to reduce herbage intake by 4.4kg DM/d, compared to cows receiving 1kg of concentrate. In both periods, milk yield increased with increasing concentrate level, with an average milk response to concentrate supplementation of 0.68kg milk DM/kg concentrate DM over the two periods. Concentrate feeding level had no effect on milk fat, protein or total solids contents. In period 2, lactose content increased in cows offered 5kg/d concentrate. Increasing concentrate feeding level increased liveweight and BCS in period 1, but not in period 2. Feeding 5kg of concentrate supplement increased enteric methane emission by 34g/d in period 1 (323 vs. 357g/d) and 41g/d in period 2 (349 vs. 390g/d) compared to 1kg of concentrate supplement. However, enteric methane emission per unit of estimated feed intake (dry matter or gross energy) or milk output (gross or energy corrected) was not affected by level of concentrate supplementation. It was concluded that under generous grazing conditions (high allowance of good quality herbage) a moderate increase in concentrate supplementation resulted in a simultaneous increase in milk yield and enteric methane emission, so that enteric methane emission per unit of milk yield was unaffected. Thus, a moderate level of concentrate supplementation of dairy cows grazing pastures of high digestibility would not be an effective enteric methane mitigation strategy.


      PubDate: 2015-05-18T14:36:23Z
       
  • Effects of rumen-protected choline with calcium salts of long chain fatty
           acids on milk yield and milk composition of middle and late lactation
           Holstein cows
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): A. Pineda , F.C. Cardoso
      The objective of this study was to evaluate the effect of rumen-protected choline (RPC) supplementation on milk production and milk composition of dairy cows. Fifty lactating multiparous Holstein cows >80 days in milk were randomly assigned to one of two treatments groups. Cows were fed with: (1) control diet (CON; n=25), not supplemented with RPC and (2) supplemented diet (RPC; n=25), supplemented with RPC (115g/cow/d). Control and supplemented cows were fed at ad libitum intake twice daily. Body weight and body condition score were measured weekly. Milk production and dry matter intake were recorded daily. Milk samples were collected twice weekly on week 3, 6, and 9 and analyzed for fat, protein, lactose, urea nitrogen, somatic cell count, fatty acid (FA) composition, and free choline concentration. Plasma was obtained on week 1, 3, 4, 6, 7, and 9 and analyzed for concentrations of free choline and non-esterified fatty acids. Cows remained in the experiment for 9 weeks. Data were analyzed using the MIXED procedure of SAS (v9.4). Higher free choline concentration in plasma (P<0.001) confirmed intake and absorption of RPC by supplemented cows. Dry matter intake (23.6 vs. 23.4kg/d), body weight (704 vs. 703kg), and body condition score (2.86 vs. 2.90; 1–5 scale) were not affected (P>0.05) by RPC supplementation (CON vs. RPC, respectively). There was no difference (P>0.05) on milk yield (36.72 and 36.81kg/d, respectively), 3.5% fat corrected milk, or energy corrected milk between supplemented and non-supplemented cows, respectively. Although production parameters were not affected by RPC supplementation, they were significantly affected (P<0.01) by period and lactation stage. While concentration of de novo and mixed (16:0+cis-9 16:1) FA in milk fat were greater in CON cows, preformed FA were greater in RPC (P<0.05) supplemented cows. Concentration of total saturated FA (P<0.001) was higher in CON cows, whereas total monounsaturated FA (cis and trans) and cis polyunsaturated FA concentrations were greater in RPC cows (P<0.05). Yield of polyunsaturated omega-3 FA was greater when RPC was added to the diet. Although milk production was not affected, supplemental RPC either in middle or late lactation resulted in milk fat composition enriched by long chain polyunsaturated FA.


      PubDate: 2015-05-18T14:36:23Z
       
  • A meta-analysis of milk production responses to increased net energy
           intake in Scandinavian dairy cows
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): Charlotte Jensen , Søren Østergaard , Ingunn Schei , Jan Bertilsson , Martin Riis Weisbjerg
      The objectives of this analysis were to develop empirical prediction models for milk yield based on cow characteristics and dry matter intake (DMI) or net energy intake (NEL) and to evaluate the effect of breed, parity, stage of lactation and the additional prediction value of using NEL estimates versus DMI estimates for incorporation in future economical optimization models of the energy level in dairy cow rations. Previous Danish response models are outdated due to higher yield capacity of cows and the use of the new Nordic feed evaluation system NorFor since 2011. A data set with 195 treatment mean observations was compiled from original data of 13 trials from Denmark, Norway and Sweden representing the breeds Danish Holstein, Danish Red, Danish Jersey, Norwegian Red and Swedish Red. Total data were grouped into 4 sub datasets according to parity; either primiparous or multiparous and according to stage of lactation; either DIM 1 to 100 (Early) or DIM 101 to 200 (Mid). All analyzed ration characteristics were calculated from NorFor principles or estimated from NorFor feed table values. Data were analyzed using linear mixed effects model with trials as random effect. Residuals were weighted by number of cows in each treatment mean. Best fit model was by use of linear and natural log transformation of NEL intake rather than DMI in the regression, especially when also including the ration concentration of the individual nutrients (g/MJ NEL), neutral detergent fibre, amino acids absorbed in the small intestine and crude fat, in the model. Breed specific responses were parallel and only differed by their intercept. In early lactation for multiparous cows with a mean NEL intake (136MJ) the model predicted an ECM response of 35.4kg and for primiparous cows with mean NEL intake (115MJ) the model predicted an ECM response of 27.8kg. Marginal milk response (kg ECM/MJ NEL) decreased more for multiparous cows (from 0.34 to 0.08) than for primiparous cows (from 0.20 to 0.15) within the observation ranges of NEL intake.


      PubDate: 2015-05-18T14:36:23Z
       
  • The effect of milk source on body weight and immune status of lambs
    • Abstract: Publication date: May 2015
      Source:Livestock Science, Volume 175
      Author(s): L.E. Hernández-Castellano , I. Moreno-Indias , A. Morales-delaNuez , D. Sánchez-Macías , A. Torres , J. Capote , A. Argüello , N. Castro
      Milk source is one of the several factors that can affect lamb body weight (BW) and immune status before weaning. The aim of this experiment was to evaluate the effect of milk source (natural rearing method, named NR group, vs. artificial rearing method using a commercial milk replacer, named MR group vs. artificial rearing method using whole powdered cow milk, named CM group) on the BW and immune status of lambs during the milk feeding and weaning period. In this study, 60 lambs were equally divided according to sex and then randomly divided in three groups (NR, MR and CM). Blood plasma was collected to measure the immunoglobulin concentration (IgG and IgM), the chitotriosidase activity and complement system activity, total complement activity (TCA) and alternative complement activity (ACA). Results showed that lambs reared with NR presented, in general, higher BW, IgG, IgM, TCA and ACA than animals reared with MR or CM at 3 and 5 days after birth (P<0.05). These differences, however, disappeared during weaning. At the end of weaning, animals from MR and CM groups showed higher BW than NR lambs (15.28, 16.89 and 17.66kg in NR, MR and CM groups, respectively, P<0.05). In addition, MR and CM groups showed higher IgM concentrations than the NR group (1.05, 1.90 and 1.60mg/mL in NR, MR and CM, respectively, P<0.05). Present findings may improve the management in sheep farms, reducing the expenses of the artificial rearing systems if the described alternative milk feeding source (whole powdered cow milk for human consumption) is selected for feeding lambs reared under an artificial rearing system. Accordingly, these results can be used for increasing the economic benefits of the sheep producers.


      PubDate: 2015-05-18T14:36:23Z
       
 
 
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