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  Subjects -> AGRICULTURE (Total: 776 journals)
    - AGRICULTURAL ECONOMICS (77 journals)
    - AGRICULTURE (526 journals)
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AGRICULTURE (526 journals)

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Journal Cover Livestock Science
  [SJR: 0.715]   [H-I: 69]   [4 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1871-1413
   Published by Elsevier Homepage  [2970 journals]
  • Effect of dietary supplementation of mannanoligosaccharides on growth
           performance, ileal microbial counts, and jejunal morphology in broiler
           chicks exposed to aflatoxins
    • Abstract: Publication date: Available online 14 May 2016
      Source:Livestock Science
      Author(s): E. Jahanian, A.H. Mahdavi, S. Asgary, R. Jahanian
      The present study was conducted to evaluate the effects of dietary inclusion of mannanoligosaccharides (MOS) on growth performance, ileal microbial population, and jejunal morphology in aflatoxin-challenged broiler chicks. A total of 336 seven-day-old Ross broiler chicks were randomly assigned into 7 experimental treatments with 4 replicates of 12 chicks each. Experimental treatments consisted of a control group (unchallenged group), and a 2 × 3 factorial arrangement of treatments, including 2 aflatoxin levels (0.5 and 2 ppm) and 3 supplemental MOS levels (0, 1, and 2g/kg). Broiler chickens were challenged with a mix of aflatoxins during 7 to 28 d of age. Results showed that increasing aflatoxin level resulted in a marked decrease (P < 0.01) in average daily feed intake (ADFI) and subsequent average daily gain (ADG); consequently it impaired (P < 0.001) feed conversion ratio (FCR). Dietary MOS supplementation increased ADFI (P < 0.01) and ADG (P < 0.001) in aflatoxin-challenged chicks, resulted in the improvements in FCR values. The retarded ADG was ameliorated by inclusion of 2g/kg of MOS into the diet of aflatoxin-challenged broilers. Although incremental levels of aflatoxin decreased (P < 0.05) carcass yield, dietary supplementation of MOS up to 2g/kg resulted in an increase in carcass yield. Contamination with 2 ppm aflatoxin resulted in increases (P < 0.001) in ileal enumerations of Escherichia coli, Salmonella, Klebsiella, and total negative bacteria at both 28 and 42 d of age. Although the lowest bacterial count was assigned to the control (unchallenged) group, supplemental MOS decreased ileal bacterial populations in aflatoxin-challenged broiler chickens. Dietary supplementation of 2g/kg MOS was more effective (P < 0.05) in depression of ileal microbial counts in broilers challenged with 0.5 ppm aflatoxin. Incremental levels of aflatoxin resulted in the remarkable (P < 0.001) decreases in villi height, villi height to crypt depth ratio, villi absorptive area, and apparent villi absorptive area. Moreover, dietary aflatoxin contamination increased crypt depth, goblet cell counts, and lymphoid follicular diameter. These changes, however, were modulated by dietary MOS supplementation up to 2g/kg. The present results indicated that although aflatoxicosis diminished growth performance, dietary inclusion of MOS ameliorated the retarded growth via suppressing ileal pathogenic bacteria and enhancing absorptive surface area in broiler chickens.


      PubDate: 2016-05-19T23:03:46Z
       
  • Extended lactation in high-yielding Holstein cows: Characterization of
           milk yield and risk factors for lactations &gt;450 days
    • Abstract: Publication date: July 2016
      Source:Livestock Science, Volume 189
      Author(s): M. Mellado, J.M. Flores, A. de Santiago, F.G. Veliz, U. Macías-Cruz, L. Avendaño-Reyes, J.E. García
      Two data files consisting of 3278 (one herd) and 4393 lactations (three herds) were used to characterize milk production of high-yielding Holstein cows milked three times per day and experiencing extended lactations (up to 1399 days) in a hot environment. Additional objectives were to identify risk factors for the occurrence of extended lactations, to assess the association between lactation length and milk yield and to determine the conception rates of cows with extended lactations and with multiple services. Thirty percent of lactations were between 450 and 1399 days. Lactation yield of cows with lactations >900 days was over 30,000kg. Average daily milk yield from 305 to >450 days in milk was 29.9 and 31.9kg for primiparous and multiparous cows, respectively. The epidemiological analysis of risk factors for extended lactations using a multiple variable logistic regression indicated that ketosis (OR=1.4), peak milk yield (<50 vs >50kgd−1, OR=1.4), temperature-humidity index at 60 days postpartum (<82 vs >82 units, OR=1.4), retained placenta (odds ratio (OR)=1.5), 305-d milk yield (<11,000 vs >11,000kg, OR=1.6) and the occurrence of metritis (OR=1.8), significantly increased the risk for lactations >450 days. Primiparous cows had less than half the risk of extended lactations (OR=0.3) compared to multiparous cows. Conception rate in cows with extended lactations decreased as number of services increased (conception rate=50.5% for 4 services and 13% for ≥14 services). The data showed that well-managed Holstein cows milked three times daily were capable of lactating for over 1200 days with remarkably high persistency and with high milk yield at drying-off. Reproductive and metabolic disorders associated with calving were important risk factors for extended lactations.


      PubDate: 2016-05-19T23:03:46Z
       
  • Multiple-trait analysis of a long-term selection experiment for
           non-destructive deformation in White Leghorns: Evolution of genetic
           parameters for traits related to eggshell strength
    • Abstract: Publication date: Available online 14 May 2016
      Source:Livestock Science
      Author(s): Olivier Gervais, Keijiro Nirasawa, Christian E. Vincenot, Yoshitaka Nagamine, Kazuyuki Moriya
      Background Economic losses resulting from poor eggshell quality are critical issue for the poultry industry, challenging researchers to find practical solutions to improve the resistance of eggshells to external pressure. Although many studies have proposed non-destructive methods to improve shell strength, relatively few long-term experiments are documented which use non-destructive deformation as a selection criterion. Using REML under a five-trait animal model, this study evaluates a long-term selection experiment for non-destructive deformation that was conducted on two divergent lines of White Leghorns and provides insight into how the selection process affects other traits related to eggshell strength (breaking strength, shell thickness, shell percentage, and shell weight). The evolution of the genetic parameters over the course of the experiment was analyzed also. Results The heritability estimates for non-destructive deformation were 0.388 (± 0.032) for the strong line and 0.415 (± 0.030) for the weak line. For eggshell breaking strength, heritability values were 0.347 (± 0.028) for the strong line and 0.482 (± 0.032) for the weak line. Strong genetic correlations were found between non-destructive deformation and eggshell breaking strength (–0.774 ± 0.031 and –0.840 ± 0.022 for the strong and weak lines, respectively). Estimated heritabilities for the other traits varied from 0.448 to 0.591 for the strong line and from 0.493 to 0.672 for the weak line. In addition, these traits showed large negative genetic correlations with non-destructive deformation, from –0.623 to –0.903 for the strong line and from –0.730 to –0.934 for the weak line. Moreover, the regression coefficients associated with the generation means of the breeding values revealed an asymmetric response between the two lines, and further analysis of the evolution of the genetic parameters over the course of the experiment hinted at possible reasons for this asymmetry. Conclusions The large genetic correlation between non-destructive deformation and eggshell breaking strength and the similarity of the heritability estimates for these two traits (medium to moderately high), suggest that non-destructive deformation can be used instead of breaking strength as a means to evaluate eggshell strength. Nevertheless, additional research is necessary to better understand the effect of selection for non-destructive deformation on factors not considered in this study, such as egg production and hatching rate.


      PubDate: 2016-05-19T23:03:46Z
       
  • Herbs and spices inclusion as feedstuff or additive in growing rabbit
           diets and as additive in rabbit meat: a review
    • Abstract: Publication date: Available online 18 May 2016
      Source:Livestock Science
      Author(s): A. Dalle Zotte, C. Celia, Zs. Szendrő
      The European ban on the non-therapeutic use of antibiotic growth promoters and limits on the use of other drugs have increased digestive disorders and mortality in growing rabbits. In addition, consumers demand natural products, and therefore synthetic active compounds should be replaced by natural ones. This has increased the search for alternatives, such as herbs, spices and their extracts (botanicals) as replacers. Plants (whole plants, leaves or seeds, mainly used as feedstuffs) and their extracts (considered as additives) are being increasingly used in animal nutrition as appetizers, digestive and physiological stimulants, colorants, and antioxidants, and for the prevention and treatment of certain pathological conditions. The digestive effects of herbs and spices have been tested primarily in humans and laboratory animals, and few trials have been performed on farm animals. Studies on the dietary inclusion of herbs and spices or their extracts in rabbit meat production are quite scarce, and the overall benefit remains unclear due to discrepancies in results, such as the use of plant preparations as galactagogues in rabbit does. Some positive results have been shown their potential, however. The dietary inclusion of Foeniculum vulgare Mill. seeds with oregano leaves has been observed to improve diet utilization, whereas the dietary inclusion of a mixture of Lupinus albus L., Trigonella foenum-graecum L., and Cassia senna L. has acted as growth promoter. Antimicrobial effects are derived especially from plant volatile oils. In the rabbit, a stabilizing effect on microbiota was observed when the diet was supplemented with thyme oil. When diets were supplemented with thyme leaves and spirulina algae, an antimicrobial effect on Clostridium coccoides, Clostridium leptum in the caecum was observed. Black cumin seeds have been shown to exert anti-inflammatory, anti-bacterial and immunomodulatory effects. Several herbs and spices (green tea, rooibos, oregano, rosemary and thyme) provide antioxidant effects rabbit dietary supplementation or inclusion in meat and meat products. Research in the use of herbs or/and spices has demonstrated their potential as feed additives and/or antioxidants, but further research is recommended to optimize effects on rabbits before practical proposals can be drafted.


      PubDate: 2016-05-19T23:03:46Z
       
  • Causal relationships between clinical mastitis events, milk yields and
           lactation persistency in US Holsteins
    • Abstract: Publication date: July 2016
      Source:Livestock Science, Volume 189
      Author(s): K. Dhakal, F. Tiezzi, J.S. Clay, C. Maltecca
      Complex relationships exist between udder susceptibility to mastitis and milk production traits. Identifying causal association between these traits could help to disentangle these complex relationships. The main objective of the study was to use producer-recorded health data to examine the causal relationship between mastitis events, milk yield and lactation persistency. A total of 48,058 first lactation cows, daughters of 2213 Holstein bulls and raised across 207 herds were analyzed using structural equation models. Traits included in the dataset were mastitis events and average test day milk yields recorded in three different periods: period 1 (5–60 DIM), period 2 (61–120 DIM) and period 3 (121–180 DIM). In addition, lactation persistency was also included. A subset including 28,867 daughters of 1809 Holstein sires having both first and second lactation across 201 herds was further investigated. In these datasets, mastitis events were defined on a lactation basis as binary trait; either a cow was assigned a score of 1 (had a mastitis event in that lactation) or a score of 0 (healthy) for that particular lactation, regardless of the time of occurrence. Total milk yield from first and second lactation were also included in the analyses. We estimated negative structural coefficient (−0.032) between clinical mastitis and test day milk production in early lactation period suggesting that mastitis results in a direct decline in milk production in early lactation. We nonetheless elicited little impact of mastitis on test day milk production of mid and late lactation periods, and on milk yield lactation persistency. Likewise the positive estimate of the structural coefficient (0.123) from mastitis event in first lactation to second lactation suggests an increased risk of mastitis in second lactation if a case of mastitis occurs in the primiparous cow. Heritability estimates obtained from the structural equation models were low for mastitis (ranged 0.04 to 0.07), and negative genetic correlations were found between mastitis events and milk yield. The study illustrates how mastitis events and production are causally linked. Through the use of structural equation models we elicited the causal effect among mastitis and production traits that evolve over the course of cow life.


      PubDate: 2016-05-13T22:35:04Z
       
  • Factors and determinants of animal genetic resources management activities
           across the world
    • Abstract: Publication date: Available online 13 May 2016
      Source:Livestock Science
      Author(s): G. Leroy, B. Besbes, P. Boettcher, I. Hoffmann, D. Pilling, R. Baumung, B. Scherf
      This paper investigates the factors affecting the implementation of various management activities related to the characterization, use and conservation of animal genetic resources (AnGR) across countries. The 128 official country reports provided for The Second Report on the State of the World's Animal Genetic Resources for Food and Agriculture were analysed based on a multivariate approach. These reports investigated topics related the national level of AnGR diversity, the extent of characterization activities, use and breeding programmes and conservation activities, as well as capacities in AnGR management and the use of biotechnologies related to livestock breeding. A large part of the variability (34.7%) of the dataset could be explained by one synthetic variable, which could be interpreted as the general extent of AnGR related activities, and indicate that country efforts on AnGR are directed relatively homogenously towards the various activities and species considered. This variable differentiated mainly OECD and BRICS countries from less developed ones. OECD and BRICS countries also appeared to be differentiated with respect to the use of some specific biotechnologies such as cloning, genetic modification and transplantation of gonadal tissues. With regards to economic and development indicators, the first synthetic variable showed large correlation with the number of researchers in agricultural sciences per inhabitant (r=0.643) and national GDP (r=0.516). Capacities in research therefore appeared to be one of the main enabling forces for activities related to AnGR and the implementation of the Global Plan of Action (GPA) for AnGR.


      PubDate: 2016-05-13T22:35:04Z
       
  • Dynamics of salivary immunoglobulin A and serum interleukin 6 levels in
           newborn calves
    • Abstract: Publication date: July 2016
      Source:Livestock Science, Volume 189
      Author(s): Stephani Fischer, Sophie Diers, Rolf Bauerfeind, Claus-Peter Czerny, Stephan Neumann
      Mucosal immunoglobulin A (IgA) is an important component of the adaptive first line immune defense. Especially in newborn calves, where diarrheal pathogens can cause severe diseases, the adaptive mucosal immunity is crucial. Regulating local IgA production is complex. Cytokines and in particular, interleukin 6 (IL-6), are described to be main actors in this process. In vaccination trails, IL-6 is used to improve the immune response with ambiguous results. Therefore, this study investigated the influence of IL-6 on the physiological development of salivary IgA production in newborn calves. Ten clinically healthy female Holstein calves were sampled over a period of four weeks. Immunoglobulin A and IL-6 were measured in serum, colostrum, milk and saliva. In addition, to compare the mucosal immune response with the systemic immune response, immunoglobulin G was measured in serum, colostrum and milk, too, using a commercial enzyme-linked immunosorbent assay (ELISA). In order to determine the ability of newborn calves to produce IL-6 actively by themselves, the relative gene expression was analyzed in peripheral blood mononuclear cells (PBMC) using a quantitative reverse transcriptase polymerase chain reaction (qPCR). Interleukin 6 gene expression in PBMCs was detected directly after birth. A significant positive correlation between serum IL-6 and salivary IgA was found on day seven (p=0.043). Furthermore, the IL-6 serum concentration peaked on day 14 and coincided with a remarkable IgA increase in saliva (p<0.01). Therefore, IL-6 seemed to play a role during the first initialization phase of a local IgA response.


      PubDate: 2016-05-13T22:35:04Z
       
  • Antimicrobial activity of plant-food by-products: A review focusing on the
           tropics
    • Abstract: Publication date: July 2016
      Source:Livestock Science, Volume 189
      Author(s): J.L. Guil-Guerrero, L. Ramos, C. Moreno, J.C. Zúñiga-Paredes, M. Carlosama-Yepez, P. Ruales
      This review characterizes the antimicrobial potential of agricultural by-products from tropical countries, assessing their suitability as substitutes for antibiotics in animal-production farms. This study responds to an increasing trend in the use of antibiotics and other growth promoters in farm animals in tropical areas. Such use is intended to improve the daily gastrointestinal welfare and also to provide resistance or prevention against acute or chronic diseases, such as infectious diarrhoea and inflammatory bowel diseases. Such diseases pose a major challenge in all countries, but tropical conditions encourage the survival of bacteria and pathogens and commensal bacteria more than in temperate climates, and therefore tropical countries need particular attention in order to solve this dilemma. Fortunately, as a substitute to antibiotics, these countries have considerable antimicrobial potential in plants – that is, agricultural by-products contain a diverse pool of bioactive compounds with antimicrobial properties, which could be employed as feed supplements to improve animal health. By-products from tropical countries constitute rich sources of bioactive compounds, such as phenolics, carotenoids, essential oils, active peptides, saponins, and sterols. Among reviewed by-products, high activity has been detected for avocado seeds, cocoa bean shell, and banana peels, while for isolated pure compounds, high activity has been reported for: alkaloids from lupine and capsaicin; phenolics such as gallic and chlorogenic acids, naringin, exiguaflavanone D, and kenusanone A; and saponins from Capsicum seeds. Some by-product extracts have shown minimum inhibitory concentration (MIC) values very close to that of their isolated pure components. In conclusion, plant-food by-products of tropical origin contain diverse active compounds which act effectively against most pathogenic bacteria tested, avoiding well-characterized cell damage.


      PubDate: 2016-05-13T22:35:04Z
       
  • Short communication: Field-trial evaluation of an automatic temperature
           
    • Abstract: Publication date: Available online 13 May 2016
      Source:Livestock Science
      Author(s): Birte Tietgen, Hans-Joachim Laue, Martina Hoedemaker, Steffi Wiedemann
      The assessment of the rectal temperature plays an important role in the early detection of bovine respiratory disease (BRD) in young calves, but the measurement is invasive and labor-intensive. The aims of this retrospective field-trial evaluation were to assess the correlation between the automatic measurements of the reticulo-ruminal (ReRu) temperature and the rectal temperature and to evaluate the diagnostic accuracy of a cumulative sum (CUSUM) control chart to detect pre-weaned calves suffering from BRD. In 150 male fattening calves (16.6 ± 3.3 d at arrival) the ReRu-temperature was obtained every 5min automatically with a wireless device over a period of 8 weeks. Data was averaged over periods of 30min and 4–6h (day periods). The 30-min means were further evaluated using CUSUM control charts. All calves were inspected by trained persons at least twice a day and rectal temperatures were measured in calves showing visible signs related to BRD. A ReRu hyperthermia (ReRu temperature ≥ 40°C) was detected in 139 calves over 30min and in 99 calves over day periods, respectively. During the evaluation period 30 animals were affected by BRD (rectal temperatures ≥ 40°C and one additional clinical sign). The correlations between rectal temperatures and both the corresponding 30min as well as the day period ReRu temperatures was r = 0.75. The sensitivity (Se) and specificity (Sp) of ReRu hyperthermia for the 30min means to detect BRD were 77% and 97%, respectively, whereas means of the day periods had a Se of 61% and a Sp of 97%. The CUSUM test revealed a Se of 71% and Sp of 98% to detect BRD. On average, by the CUSUM method calves with clinical signs of BRD were identified 3.5 d earlier. In conclusion, the automated ReRu temperature measurement possesses potential for the early detection of febrile responses in very young calves warranting further investigations.


      PubDate: 2016-05-13T22:35:04Z
       
  • Host-parasite ecology of keds (Melophagus ovinus (L.)) relative to sheep
           breed and age on Wyoming rangeland
    • Abstract: Publication date: Available online 5 May 2016
      Source:Livestock Science
      Author(s): John D. Scasta, K. Koepke
      Sheep keds (Melophagus ovinus (L.)), an obligate external parasite of economic concern, are a continual problem in high-elevation grazing situations in most temperate sheep productions areas of the world. The influence of sheep breed, age, and the interaction of breed⁎age on host-parasite ecology, could inform integrated keds management strategies. We measured ked density and presence/absence on Rambouillet, Hampshire, and Suffolk ewes in Wyoming, USA to determine the role of breed, ewe age, and breed⁎age interaction on ked parasitism. Eighteen ewes per breed group were examined for ked presence and ked density with sub-groups within each breed of 1, 2, and 3+ years of age. We used a generalized linear mixed model (GLMM) to analyze the effect of breed, age, and the interaction of breed and age, on a stacked response variable ‘ked infestation’ that is a function of both ked presence and density. Ked infestations differed by ewe age (p = 0.0153; F = 4.55) and by ewe breed (p = 0.0178; F = 3.30). Ked infestation increased with ewe age, as 29% of yearling ewes had keds and 63% of three-year old ewes had keds. Ked infestation was the greatest on the fine-wool Rambouillet ewes (72% presence; 1.4 keds per ewe), and was lower on the medium-wool breeds (Hampshire ewes had 39% presence and 1.0 keds per ewe and Suffolk ewes had 22% presence and 0.3 keds per ewe). The breed⁎age interaction did not significantly influence ked infestation in our joint model of the stacked bivariate ked infestation response outcome (p = 0.1292; F = 1.75). The lack of a significant interaction is attributed to the relatively large variance around the mean for such small breed-age sub-groups and warrants additional study. Our results have implications for parasite management as 100% of three-year old Rambouillet ewes had keds present, but none of the yearling Suffolk ewes had any keds and only 29% of three-year old Suffolk ewes had keds present. The results from our study indicate keds do discriminate by breed perhaps due to an ecological adaptation for a wool-environment that is dense and comprised of a long staple -- features characteristic of the Rambouillet ewes in our study. Integrated ked management strategies could manipulate this host-parasite ecology by selecting resistant breeds and/or strategically treating the most susceptible ewes. For example, this could be all Rambouillet ewe ages or only Suffolk ewes > 2 years of age.


      PubDate: 2016-05-07T22:18:18Z
       
  • Gastrointestinal transport of calcium and phosphate in lactating goats
    • Abstract: Publication date: Available online 7 May 2016
      Source:Livestock Science
      Author(s): Svenja Starke, Julia Reimers, Alexandra S. Muscher-Banse, Bernd Schröder, Gerhard Breves, Mirja R. Wilkens
      Previous studies gave evidence for the assumption that in contrast to sheep, dairy goats can adapt to lactation-induced challenges of calcium (Ca) homeostasis by effective adaptation of gastrointestinal Ca absorption. Ca and phosphate (Pi) homeostasis are known to be closely related challenged during lactation. However, for both, Ca and Pi homeostasis, the underlying molecular mechanisms and their regulation during lactation in goats have only marginally been investigated so far. Therefore, the present study aimed to investigate the impact of lactation on gastrointestinal Ca and Pi absorption in dairy goats on a functional level using the Ussing chamber technique to determine macromineral fluxes across gastrointestinal epithelia, and on a structural level by analyzing gastrointestinal RNA and protein expression of key genes involved in transcellular Ca and Pi transport. Besides slightly increased functional Ca absorption and elevated expression of transient receptor potential vanilloid channel type 6, calbindin D 9K and plasma membrane Ca 2+ -ATPase type 1 in jejunum, an upregulation of Ca absorption in lactating goats also occurred in the rumen in terms of increased Ca fluxes. However, the exact molecular and regulatory mechanisms have to be examined in more detail. Interestingly, intestinal Pi absorption in duodenum and jejunum was downregulated by lactation on functional level, and in accordance, sodium-dependent P i cotransporter type IIb RNA and protein expression were decreased in jejunum. Whether this downregulation of intestinal Pi absorption can be attributed to sufficient Pi supply from endogenous sources or to lactation-induced increased dietary Pi intake has still to be investigated.


      PubDate: 2016-05-07T22:18:18Z
       
  • Plant and natural product based homemade remedies manufactured and used by
           farmers of six central Swiss cantons to treat livestock
    • Abstract: Publication date: Available online 5 May 2016
      Source:Livestock Science
      Author(s): Tinetta Bischoff, Christian R. Vogl, Silvia Ivemeyer, Franziska Klarer, Beat Meier, Matthias Hamburger, Michael Walkenhorst
      The use of medicinal plants and other natural multicomponent remedies might be one measure to reduce the use of antibiotics in livestock. Ethnoveterinary research has the potential to identify promising natural remedies. The knowledge about remedies for livestock was collected from farmers in six central Swiss cantons, Glarus, Obwalden, Nidwalden, Schwyz, Zug and Uri. Between February and April 2013 49 interviews with 63 farmers (25 females and 38 males, aged 24 to 74) were conducted. We collected information on the manufacturing of 370 homemade remedies. Of these, 114 contained no plants, 26 contained a mixture of two to five plants, and 230 contained one plant species (defined as homemade single-herbal remedy report (HSHR)). These 230 HSHRs represented 68 plant species belonging to 35 different botanical families. Thirteen species were reported for the first time for ethnoveterinary use in Switzerland. Matricaria recutita, Calendula officinalis, Urtica dioica and Coffea were the most frequently used ingredients of HSHR. A total of 278 use reports (UR) were described for the 230 HSHR, (233 UR for treating cattle). Treatment of skin disorders (QD), gastrointestinal diseases and metabolic dysfunction (QA) were the most frequently mentioned uses for these remedies. Fewer uses were linked to treatments of the respiratory system (QR), the genito-urinary (QG) and musculo-skeletal systems (QM). In the categorie QA the most UR were described for Matricaria recutita, Linum usitatissimum, and Camellia sinensis. Quercus robur was mainly used to treat diarrhoea in calfs, Coffea Arabica to treat general gastrointestinal troubles, colic, abdominal pain or diarrhoea, and Arthemisia absinthium to treat general gastro-intestinal disorders, diarrhoea or lack of appetite. For four orally administered plant species (Artemisia absinthium, Avena sativa, Citrus x limon, Quercus robur) daily oral doses were determined for the first time (median: 0.03, 6.16, 0.01 and 0.58g dry plant equivalent per kg0.75). In the category QD the most often described plant species were Calendula officinalis, Matricaria recutita, Picea abies, Sanicula europaea and Senecio ovatus. For the latter two plant species we determined for the first time an ethnoveterinary based concentration in the finished product (median: 0.13 and 0.39g dry plant equivalent per 100g finished product). Medicinal plants are known, and used by farmers of central Switzerland mostly for treatment of skin and gastrointestinal diseases. According to recent pharmaceutical and human clinical research several plant species documented in this ethnoveterinary study are worth to be further investigated in clinical trials with livestock.


      PubDate: 2016-05-07T22:18:18Z
       
  • Genetic parameters for harmony and gaits in Hispano-Arabe horses estimated
           by Bayesian methods and Restricted Maximum Likelihood
    • Abstract: Publication date: June 2016
      Source:Livestock Science, Volume 188
      Author(s): M.M. Gómez, L.T. Gama, J.M. León, J. Fernández, S.A. Attalla, J.V. Delgado
      Genetic parameters for harmony and gaits (walk, trot and canter) were estimated in the Hispano-Arabe horse breed. The data set included 12,957 records of 901 animals, collected from 2000 to 2014, and was analysed by Bayesian procedures (Gibbs Sampling) and Restricted Maximum Likelihood. The multivariate animal model with repeated records included management group, sex, combination of year and event of evaluation, season of evaluation as fixed effect, plus age at classification and proportion of Arabian genes as linear covariates and additive genetic, permanent environmental and judge as random effects. Bayesian heritability/repeatability estimates for harmony, walk, trot and canter were 0.18/0.35, 0.10/0.18, 0.13/0.27 and 0.13/0.20, respectively, with standard errors from 0.02 to 0.05. Estimates of additive genetic correlations among harmony and gaits traits ranged from 0.45 to 0.83, and were stronger between harmony and trot or canter than between walk and trot. Analyses by Restricted Maximum Likelihood yielded similar results, and correlations between breeding values estimated by both procedures ranged from 0.80 to 0.94.


      PubDate: 2016-05-07T22:18:18Z
       
  • Ammonia and greenhouse gas emissions from different types of deep litter
           used for pig rearing
    • Abstract: Publication date: June 2016
      Source:Livestock Science, Volume 188
      Author(s): Liping Zhang, Jing Sheng, Yuefang Zhang, Liugen Chen, Guofeng Sun, Jianchu Zheng
      Ammonia (NH3) and greenhouse gas (GHG) emission during pig rearing on deep litter has been rarely reported. To evaluate the emission of NH3 and GHGs according to the compositions of the deep-litter systems during pig rearing, we selected three different types of deep-litter systems: (a) RM, composed of 60% mushroom growth media and 40% rice husk; (b) RS, composed of 60% sawdust and 40% rice husk; and (c) RV, composed of 60% vinasse and 40% rice husk. Samples of the gases emitted were collected continuously using the static box method during one production cycle (150 d). The results showed that the patterns of NH3 volatilization and CH4 emission differed across the three deep-litter systems, but no significant differences were found in the pattern of N2O and CO2 emission. Further, the total quantity of NH3 and GHG emission showed significant differences. Material flow analysis indicated that gaseous loss was the main pathway for escape of N or C. Thus, the use of RS could mitigate the emission of NH3, N2O and CH4 (3.82kg, 1.50kg and 5.46kg, respectively) and limit the effect of GHGs in terms of the emission equivalent carbon value (28% and 86% lower than that of RM and RV, respectively). Thus, the RS system was the most suitable with regard to reduction of environmental pollution.


      PubDate: 2016-05-07T22:18:18Z
       
  • Investigating mutual relationship among milk fatty acids by multivariate
           factor analysis in dairy cows
    • Abstract: Publication date: Available online 25 April 2016
      Source:Livestock Science
      Author(s): G. Conte, A. Serra, P. Cremonesi, S. Chessa, B. Castiglioni, A. Cappucci, E. Bulleri, M. Mele
      The interpretation of mutual relationship among milk fatty acids (FA) is not easy due to the high number of FA contained in milk fat and to the high degree of correlation among them. Multivariate analysis includes different statistical approaches that could help explaining complex pattern of variables. In this study, Multivariate Factor Analysis (MFA) was used to decompose the correlation matrix of 47 FA and milk production traits (milk yield and protein and fat content) measured in 300 Italian Holstein Friesian cows reared in the North of Italy in 23 commercial dairy farms, representative of the intensive dairy system. MFA was able to extract seven latent factors with specific biologic meaning: secretion of Long Chain FA (KLCFA), mammary FA de novo synthesis (Km), rumen biohydrogenation (Kbh), synthesis of odd chain FA (Ko), synthesis of branched chain FA (Kb), mammary desaturation activity (Kd), milk yield (Kmy). According to the pattern of communalities of the factor analysis, C18:3c9c12c15 was the only FA, along with C18:2t11c15, to be uncorrelated with the other variables and it seemed to be excluded by the metabolic pattern described by the seven factors. The desaturation products of the SCD enzyme were independently associated to three latent factors, suggesting new insights in the regulation of SCD activity. Factors were considered as new quantitative phenotypes related to prominent features of milk FA profile. With the aim of evaluating the feeding regimen and animal effects, latent factors were analysed with a mixed model, which considered the fixed effect of lactation stage, parity, some feeding regimen characteristics and the random effect of bull. Lactation stage significantly affected Km and Kmy factors. In perspective, the seven factors extracted by applying MFA analysis to milk FA composition could be considered as new and more informative traits to test the effect of endogenous and exogenous variation factors.


      PubDate: 2016-04-27T21:32:50Z
       
  • Homogeneity and heterogeneity of variance components for milk and protein
           yield at different cluster sizes in Iranian Holsteins
    • Abstract: Publication date: Available online 26 April 2016
      Source:Livestock Science
      Author(s): Jamshid Ehsaninia, Navid Ghavi Hossein-Zadeh, Abdol Ahad Shadparvar
      This study was conducted to investigate the homogeneity and heterogeneity of variance components for milk yield (MY) and protein yield (PY) at different cluster sizes and to evaluate effect of different data transformation methods on the ranking of elite animals in Iranian Holsteins. Data included 305-day lactation records for MY and PY from the first three lactations that were collected in the period from 1983 to 2014 by the Animal Breeding Center and Promotion of Animal Products of Iran. The mean and standard deviation of 305-day MY and PY for each herd were obtained and used as the basis for clustering the herds. Four different data transformation methods including Logarithmic, Arc sin, Square root and Box-Cox were applied and the data were tested for heterogeneity of variance before and after transformation using Bartlett's test. Genetic parameters and heritability estimates as well as animals’ breeding values (BVs) were estimated by the VCE program, using animal model. The results indicated the heterogeneity of variance in all clusters (P<0.01) before transformation. All methods of data transformation decreased the heterogeneity of variance components for MY and PY in the first three lactations and some of these methods caused removing the heterogeneity of variance. Results showed that the heritability estimates of MY and PY were decreased from the first lactation to third, also heritability estimates of transformed data were slightly higher than the original data ones. Some re-ranking of animals occurred from the transformation, but the Box-Cox method only had slight effects on the overall ranking and rank correlations of animals. The applied data transformation caused a substantial re-ranking of elite sires and dams in the EBV for each cluster. This study provided evidence that the applied transformation methods reduced the bias in the EBVs due to heterogeneous variances and increased the accuracy of bull-dam selection. Therefore, effects of heterogeneous variances need to be accounted for in genetic evaluation of Holstein cows in Iran.


      PubDate: 2016-04-27T21:32:50Z
       
  • Genomic-polygenic and polygenic evaluations for milk yield and fat
           percentage using random regression models with Legendre polynomials in a
           Thai multibreed dairy population
    • Abstract: Publication date: Available online 27 April 2016
      Source:Livestock Science
      Author(s): Danai Jattawa, Mauricio A. Elzo, Skorn Koonawootrittriron, Thanathip Suwanasopee
      The objectives of this research were to compare estimates of variance components, genetic parameters, prediction accuracies, and rankings of animals for 305-d milk yield (305-d MY) and 305-d fat percentage (305-d FP) from random regression genomic-polygenic (RRGM) and random regression polygenic (RRPM) models. In addition, RRGM and RRPM prediction accuracies and rankings were compared with those from a standard cumulative 305-d genomic-polygenic model (SCGM). The dataset contained first-lactation monthly test-day records (69,029 for MY and 29,878 for FY) from 7,206 Holstein-upgraded cows located in 761 Thai farms. Genotypic data included 74,144 actual and imputed SNP from 1,661 animals. Variance components and genetic parameters were estimated using REML procedures. The RRGM and RRPM included contemporary group (herd-year-season), calving age, heterosis, and third-order Legendre population regression coefficients. Random effects were animal additive genetic third-order Legendre regression coefficients, permanent environment third-order Legendre regression coefficients, and residual. The SCGM contained contemporary group (herd-year-season), calving age and heterosis as fixed effects, and additive genetic and residual as random effects. The RRGM yielded higher additive genetic variances and heritabilities for 305-d MY and 305-d FP than RRPM, whereas correlations between MY and FY were similar in both models. The highest prediction accuracies for both traits were for RRGM, followed by RRPM, and the lowest ones were from SCGM. Similarly, the highest rank correlations were between animal EBV for 305-d MY and 305-d FP from RRGM and RRPM, followed by those between RRGM and SCGM, and the lowest ones were between RRPM and SCGM. The higher heritability estimates and higher prediction accuracies for RRGM than for RRPM and SCGM indicated that higher selection responses for 305-d MY and 305-d FP may be achieved in this Thai dairy population by utilizing a random-regression model and genotypic information in addition to phenotypes and pedigree.


      PubDate: 2016-04-27T21:32:50Z
       
  • The effect of alfalfa saponins on the contractility of bovine isolated
           abomasum and duodenum preparations
    • Abstract: Publication date: Available online 26 April 2016
      Source:Livestock Science
      Author(s): Marta Mendel, Magdalena Chłopecka, Natalia Dziekan, Wojciech Karlik
      Saponins, a vast group of secondary plant metabolites, occur naturally in plants that are commonly present in ruminants’ diet or plants that are used as phytogenic feed additives. They have gained particular attention among ruminant nutritionists due to numerous health benefits resulting in improved animal performance and feed conversion efficiency. Despite the broad knowledge of saponins’ effects of on cattle, little is known about their impact on gut motility. Therefore, the effect of two structurally divergent alfalfa saponins on the contractility of abomasum and duodenum smooth muscle was examined. The study was conducted on tissues obtained from routinely slaughtered, healthy cows. The experiments were carried out on longitudinal and circular smooth muscle preparations under isometric conditions. The effect of hederagenin and medicagenic acid in a concentration range of 0.001–100µM was verified in a non-cumulative manner on acetylcholine-precontracted smooth muscle specimens. The results are expressed as percentage of the control contraction induced by acetylcholine. Generally, both triterpenoid saponins caused significant enhancement of acetylcholine-induced contraction of abomasum and duodenum preparations. Hederagenin generated dose-dependently significant increase of acetylcholine-evoked contraction of abomasum strips. The strongest contraction caused by hederagenin in a concentration of 100µM was observed in abomasal circular smooth muscle and amounted to 184.1±15.5% of the control treatment. Similarly, in case of duodenum hederagenin increased smooth muscle contractility dose-dependently. Hederagenin applied in the highest tested concentration doubled the force of acetylcholine-induced contraction in duodenal longitudinal smooth muscle. Medicagenic acid caused a remarkable increase of abomasum but not duodenum smooth muscle contractility. The contractile effect of medicagenic acid was observed in a concentration range of 0.001–10µM. The highest contractions of abomasal longitudinal and circular smooth muscle generated by medicagenic acid exceeded 150% of the control treatment with acetylcholine. All reactions caused by hederagenin and medicagenic acid were reversible and did not abolish the spontaneous motoric activity of specimens. Taking into consideration the physicochemical properties of saponins it is postulated that the contractile effect of hederagenin and medicagenic acid results from their impact on the fluidity or plasticity of the membrane and subsequently the ion flow through cell membrane. The increased ability of cells to depolarize can explain the enhancement of the response to acetylcholine. The reversibility of induced contractions, preserved spontaneous contractility and remained reactivity of smooth muscle after saponin treatment indicate that the effect caused by alfalfa saponin does not result from cell membrane damage.
      Graphical abstract image

      PubDate: 2016-04-27T21:32:50Z
       
  • The complete mitochondrial DNA sequence of the Montecristo goat
    • Abstract: Publication date: Available online 22 April 2016
      Source:Livestock Science
      Author(s): Maria Grazia Doro, Giuseppina Casu, Giovanni Giuseppe Leoni, Salvatore Naitana, Mario Pirastu, Andrea Novelletto, Fulvio Fraticelli
      The remote island of Montecristo is renowned for a resident goat population, whose origins are unclear. We describe the complete mtDNA sequence of a male specimen captured on the island. The sequence turned out to belong to haplogroup (Hg) A. Our results exclude that the sequence belongs to a lineage more closely related to bezoars than domestic goats. The lineages most similar to the Montecristo sequence are currently found in Western Europe, favouring partial feralization for the Montecristo isolate. Positioning of the Montecristo mitogenome in the emerging phylogenetic tree for domestic goats reveals a new lineage with multiple derived nucleotide states shared with lineages so far described in Europe as well as in North Asian breeds. This reveals the presence, within Hg A, of lineages with a palearctic distribution, whose descendants are now grown from Eastern Asia to Western Europe.


      PubDate: 2016-04-22T21:15:27Z
       
  • Evaluation of the innate immune response of Angus heifers with genetic
           marker variation for intramuscular fat deposition following a
           lipopolysaccharide challenge,
    • Abstract: Publication date: Available online 20 April 2016
      Source:Livestock Science
      Author(s): J.O. Buntyn, J.A. Carroll, T. Smith, J.D. Rivera, N.C. Burdick Sanchez, P.R. Broadway, S.M. Falkenberg, T.B. Schmidt
      This study evaluated the effect of genetic selection for markers related to marbling deposition in Angus heifers on the immune response following a lipopolysaccharide (LPS) challenge. Fall-born heifers (n=19;~7 months of age, 274+24kg) with genetic variation for marbling were utilized including 10 heifers with no genetic markers (No-MVP) and 9 heifers with >1 markers (1+MVP). Genotypic variation for quantitative trait loci QG1 and QG2 heifers was determined. Twenty-four hour (h) prior to the LPS challenge, heifers were fitted with jugular catheters and vaginal temperature (VT) monitoring devices. Temperature monitoring devises were programed to record VT in 1min intervals. On day (d) 0, 2h prior to LPS challenge and 8h post challenge, serum was collected in 0.5h intervals (0800–1800h). Serum was also collected at 12, 16, 20, and 24h post LPS challenge. The LPS challenge was administered to the heifers at 1000h via intravenous bolus (0.5μg/kg BW). Serum was analyzed for cortisol, TNF-α, IL-6, IFN-γ, and haptoglobin (HAPT). A treatment x time interaction existed (P≤0.001) for VT; prior the LPS challenge, VT was similar. Vaginal temperature was elevated from 6 to 21h post-LPS in 1+MVP compared to No-MVP. A treatment x time interaction (P=0.02) was observed for IFN-γ. Prior to the LPS challenge, IFN-γ concentrations were similar between the two groups. However, 3.5 to 7h post-LPS concentrations of IFN-γ were greater (P≤0.05) for 1+MVP compared to No-MVP. There was no treatment effect (P≥0.17) for cortisol, TNF-α or IL-6. A treatment effect (P=0.02) was observed for HAPT; 1+MVP had decreased HAPT compared to No-MVP. Overall, results suggest that heifers selected based upon genetic markers for marbling may have an altered immune in response when challenged with LPS.


      PubDate: 2016-04-22T21:15:27Z
       
  • The effect of maternal or artificial milk, age and sex on three muscles
           fatty acid profile of Damascus breed goat kids
    • Abstract: Publication date: Available online 21 April 2016
      Source:Livestock Science
      Author(s): E. Tsiplakou, G. Papadomichelakis, D. Sparaggis, K. Sotirakoglou, M. Georgiadou, G. Zervas
      Meat quality is related to a variety of muscle types consisting of different muscle fibers which are a reflection of its energy requirements and lipid content. Due to that, factors such as source of suckled milk, age and sex which affect the fatty acid (FA) profile and associated with meat quality should be determined in different muscles, since humans consume different parts of the carcass. A total of 40 goat kids of Damascus breed were used to determine the effect of rearing system, age and sex on the FA profile of Semimembranosus proprius (SP), Longissimus dorsii (LD) and Triceps brachii (TB). The goat kids were assigned into two groups balanced for body weight and sex. The first group (n=20), (10 male and 10 female goat kids) underwent natural rearing and received only maternal milk until weaning. The second group (n=20) (10 male and 10 female goat kids), was subject to artificial suckling with a commercial milk replacer. At weaning (49 days of age), 10 animals from each group were weighed and slaughtered. The remaining goat kids of both groups, after weaning were fed daily 100g barley hay per animal and a commercial concentrate diet ad libitum up to 98 days of age, where they were also weighted and slaughtered. The results showed that the body weight and the growth rate were significantly higher in males than females goat kids when fed with maternal milk. Moreover, the growth rate was significantly higher in the naturally compared with the artificially goat kids. The muscles FA composition, especially the branched chain FA, saturated FA and n-3 FA, reflects that of the milk source (maternal or artificial). Significant differences were found among the three muscles (SP, LD and TB) of goat kids for several individual FAs. The concentrations of C18:0 and trans C18:1 FA increased significantly whereas n-3 FAs decrease in the fat of goat kids slaughtered at 98 compared 49 days of age, due to the shift from milk to a fodder diet. Sex did not affect the FA profile of goat kids. In conclusion, naturally reared goat kids is better slaughtered at younger age before a shift from milk to a fodder diet whereas a fodder diet compared with a milk replacer can improve muscle FA profile of goat kids.


      PubDate: 2016-04-22T21:15:27Z
       
  • Analysis of the rumen bacteria and methanogenic archaea of yak (Bos
           grunniens) steers grazing on the Qinghai-Tibetan Plateau
    • Abstract: Publication date: Available online 13 April 2016
      Source:Livestock Science
      Author(s): Dan Xue, Huai Chen, Fang Chen, Yixin He, Chuan Zhao, Dan Zhu, Lile Zeng, Wei Li
      Yak is an important domesticated ruminant on the Qinghai-Tibet Plateau in China. The prokaryotic community of yak remains largely uncharacterized when compared to that of other livestock species. In the present study, high-throughput sequencing of 16S rRNA genes (targeting bacterial and archaeal) and clone library of mcrA gene (targeting methanogenic archaea) were applied to investigate the rumen prokaryotic community structure. High-throughput sequencing results indicated that the rumen prokaryotic community consisted of 29 phyla, 40 classes, 63 orders, 77 families, and 79 genera. Bacteroidetes (59.1%) was the most abundant phylum, followed by Firmicutes, Proteobacteria, Fibrobacteres and Euryarchaeota. Prevotella was the predominant genus, averaging 28.5% of all rumen prokaryotic genera. Archaea accounted for 2.26% of the total prokaryotic community, with their community dominated by Methanobacteriaceae (82%), followed by Methanomassiliicoccaceae, and Methanosarcinaceae. Compared with the clone library of mcrA gene, high-throughput sequencing of 16S rRNA genes yielded a greater coverage of methanogenic archaea diversity. However, both molecular techniques showed that Methanobrevibacter is the predominant archaea of rumen microbiota in yaks grazing natural pastures. Our results should facilitate understanding of the complex rumen ecosystem and the main process of ruminal methanogenesis, which may help to further mitigate CH4 emissions from ruminants.


      PubDate: 2016-04-17T15:52:43Z
       
  • Expression of Genes related to Sweet Taste Receptors and Monosaccharides
           Transporters along the Gastrointestinal Tracts at different Development
           Stages in Goats
    • Abstract: Publication date: Available online 13 April 2016
      Source:Livestock Science
      Author(s): Tao Ran, Hengzhi Li, Yong Liu, Shaoxun Tang, Xuefeng Han, Min Wang, Zhixiong He, Jinghe Kang, Qiongxian Yan, Zhiliang Tan, Chuanshe. Zhou
      In non-ruminants, sweet taste receptor and monosaccharide transporters are important components of nutrient chemosensing in the intestinal tracts. Ruminants, however, have evolved a polygastric digestive system linked to a transition in nutrient supply from readily-digestible carbohydrate (lactose) in milk during the pre-ruminant suckling phase to poorly-digestible structural carbohydrates when the rumen becomes functional. Whether these developmental and feed changes alter the mRNA expression of genes related to monosaccharide sensing (Taste receptor family 1 member 2, T1R2; Taste receptor family 1 member 3, T1R3) and transporting (monosaccharide transporters Na+/glucose co-transporter, SGLT1; glucose activated ion channel, SGLT3; solute carrier family 2 member 5, GLUT5; solute carrier family 2 member 2, GLUT2) are unknown. This study investigates the expression of sweet taste receptors (T1R2 and T1R3) and monosaccharides transporters (SGLT1, SGLT3, GLUT5 and GLUT2) along the gastrointestinal tracts (GIT) during different stages of development (suckling, weaning and grazing) in goats. The results showed that the expression of T1R2 decreased with age, and was mainly expressed in the duodenum and jejunum. Although T1R3 expression in different GIT segments fluctuated during growth, there was an increase with age, with the abomasum showing the greatest expression. Both SGLT1 and SGLT3 were mainly expressed in the jejunum at all ages, with the greatest expression in the middle jejunum during suckling, and decreased greatly (P<0.05) during weaning and grazing. GLUT5 was mainly expressed at the duodenum and jejunum, with differences (P<0.05) between suckling and the later developmental stages. No expression of GLUT5 was detected at the rumen and abomasum at any stage, but was noted in the ileum, cecum, colon and rectum during suckling, but with lower abundances during weaning and grazing. The expression of GLUT2 was detected only in the small intestine and decreased with age. The expression of T1R2 correlated (P<0.05) with SGLT1, SGLT3, GLUT5 and GLUT2. There were correlations (P<0.01) between the expressions of SGLT3 and SGLT1, as well as between SGLT3 and GLUT5. The current results indicate that: 1) the ability of the GIT of goats to absorb monosaccharides varies during development, being greatest at the suckling stage; 2) the duodenum and jejunum play a critical role in sensing and absorption of monosaccharides; 3) the mRNA expressions of sweet taste receptors and various transporters correlated well in the GIT of goats.


      PubDate: 2016-04-17T15:52:43Z
       
  • Editorial Board
    • Abstract: Publication date: May 2016
      Source:Livestock Science, Volume 187




      PubDate: 2016-04-17T15:52:43Z
       
  • Intake, total and partial digestibility of nutrients, and ruminal kinetics
           in crossbreed steers fed with multiple supplements containing spineless
           cactus enriched with urea
    • Abstract: Publication date: Available online 13 April 2016
      Source:Livestock Science
      Author(s): C.T.F. Costa, M.A. Ferreira, J.M.S. Campos, A. Guim, J.L. Silva, M.C.B. Siqueira, L.J.A. Barros, T.D.Q. Siqueira
      Multiple supplements are used in pasture-based systems to manage deficits in the forage, and they can be composed of a controller mixture (e.g. urea + mineral mixture) to regulate the intake of the animals. The effect of using spineless cactus enriched with urea in place of traditional multiple supplements was evaluated for nutrient intake, partial and total digestibility, and ruminal kinetics in crossbred steers. Five steers, ½ Holstein x Zebu, with permanent cannulas in the rumen and with an average initial body weight of 240±22.1kg, were used in a 5×5 Latin square. The treatments consisted of four levels of inclusion of urea (0, 1, 2, and 3% in dry matter (DM) and a control treatment with a traditional multiple supplement. The Tifton-85 hay, used as forage, had high neutral detergent fiber (659g NDF kg−1 of DM) and low crude protein (62g CP kg−1 of DM) content. There was a linear increase in the intake of CP and a quadratic effect in intake of dry matter (DM), organic matter (OM), non-fiber carbohydrates (NFC), NDF, and digestible OM according to the urea inclusion level. The maximum point for total OM digestibility (645g kg−1) was with the inclusion of 2% urea. There was an improvement in ruminal digestibility of DM, NDF, and CP when spineless cactus was enriched with urea. The ruminal pool of DM, NDF, and iNDF did not change with the inclusion of urea in the diets. Increased intake rate (ki) was observed when spineless cactus was enriched with urea. The passage rate (kp) of spineless cactus enriched with 3% urea was similar to the control diet. The rate of NDF degradation increased in the diets enriched with spineless cactus. It is suggested that spineless cactus enriched with up to 2% urea efficiently replaces traditional multiple supplements.


      PubDate: 2016-04-17T15:52:43Z
       
  • Feed Restriction Alters Lipogenic and Adipokine Gene Expression in
           Visceral and Subcutaneous Fat Depots in Lamb
    • Abstract: Publication date: Available online 12 April 2016
      Source:Livestock Science
      Author(s): Jinli Yang, Xinxing Lu, Xianzhi Hou, Hairong Wang, Caixia Shi, Guichao Wang, Shuqing Wu, Aiwu Gao
      Currently, lipogenic and adipokine gene expression patterns in different fat depots during long-term feed restriction in growing lambs are poorly understood. This study aimed to determine the effects of long-term nutritional deficiency on lipogenic and adipokine gene expression in subcutaneous and visceral fat depots in lambs. Twenty male lambs (4 months old; 21.81±0.75kg body weight) were randomly assigned to either control or feed-restricted groups. After 60 days of maintenance-level feed restriction, femoral, omental, mesenteric, epicardial, and perirenal fat were collected. Gene expressions were estimated by quantitative real-time PCR, and plasma parameters were also determined. The results showed that feed restriction increased the plasma concentration of NEFA (P<0.05) at 30 days, and decreased the plasma concentration of triglycerides, glucose, and insulin (P<0.05) at 30 days and 60 days. Feed restriction decreased lipogenic gene expression (acetyl coenzyme A carboxylase alpha and fatty acid synthase) in all five fat depots. The related key regulating gene PPARγ mRNA decreased (P<0.05) in femoral, omental, and mesenteric fat depots, while sterol regulatory element binding transcription factor 1 decreased (P<0.05) in femoral fat depots. Perilipin, as a barrier to lipolysis, decreased (P<0.05) in femoral, omental and perirenal fat depots of the feed restriction group. Adipose tissue-derived hormone leptin mRNA decreased (P<0.05) in all five fat depots, while adiponectin decreased (P<0.05) only in omental, mesenteric, and epicardial depots. Macrophage marker CD68 mRNA increased (P<0.05) in femoral and mesenteric fat depots. In addition, tumor necrosis factor-α mRNA increased in femoral, omental, and mesenteric depots, whereas IL-1β mRNA increased in femoral and perirenal depots. IL-6 expression decreased in femoral, omental, and epicardial fat depot at the end of feed restriction. Nutritional deficiency induced different changes in lipogenic and adipokine gene expression between visceral and subcutaneous adipose tissue. The decreased leptin, adiponectin, and increased inflammatory factors may inhibit lipogenesis and stimulate lipolysis to protect the body against the threat of starvation.


      PubDate: 2016-04-17T15:52:43Z
       
  • Influence of carbohydrate source on digesta kinetics and postprandial
           glucose responses of broiler chicks
    • Abstract: Publication date: Available online 8 April 2016
      Source:Livestock Science
      Author(s): O.O. Adeleye, A.D. Ologhobo, B.T. Oje-Adetule
      This study was conducted to investigate the effect of different carbohydrates included in the diets of broiler chicks on digesta kinetics and postprandial plasma glucose responses. Starch extracted from different energy feedstuffs, maize, wheat, millet, sweet potato, and cassava, was used as the main energy source in each diet. Ninety 1-d-old broiler chicks were assigned to 5 diets containing 45±3% of each starch with 3 replicates and 6 broiler chicks per replicate. The digesta kinetics study involved administering 50mg chromic oxide orally to each broiler chick before feeding. Excreta produced was collected hourly for the first 8h and 10, 12, 24, 36, and 48h, and their Cr2+content determined. Cumulative Cr2+excretion, times at 1 (T1) and 50% (T50) Cr2+excretion, time at peak Cr2+excretion, and mean retention time (MRT) were estimated. Two broiler chicks per replicate were used for the plasma glucose response study where glucose concentration was measured from blood collected from the wing vein of each broiler chick up to 480min postprandial. Postprandial glucose responses, as well as hydrolysis indices were calculated. Digesta transit time variables, T1, T50, time at peak Cr2+excretion, and MRT varied and were greatest for cassava starch diet at 0.2, 6.20, 8.00, and 19.45h, respectively, and least for the sweet potato starch diet at 0.1, 4.2, 5.0, and 17.20h, respectively. Plasma glucose response variables also varied considerably (P<0.05) between treatments and were attributed to starch granule size and dimensions. However, no relationship was observed between digesta kinetics and postprandial glucose responses of broiler chicks fed the experimental diets.


      PubDate: 2016-04-12T15:37:14Z
       
  • Effects of a high carbohydrate diet and arginine supplementation during
           the rearing period of gilts on osteochondrosis prevalence at slaughter.1
    • Abstract: Publication date: Available online 8 April 2016
      Source:Livestock Science
      Author(s): D.B. de Koning, B.F.A. Laurenssen, R.E. Koopmanschap, E.M. van Grevenhof, P.R. van Weeren, W. Hazeleger, B. Kemp
      Osteochondrosis (OC) is a consequence of necrotic growth cartilage formation early in life and suggested to be associated with lameness and premature culling of sows. Higher insulin, glucose, and insulin-like growth factor-1 (IGF-1) are associated with increased OC in horses and are affected by carbohydrates. If dietary composition can affect OC through metabolic parameters in sows, it could be a tool in practice to reduce OC prevalence. This study examined if OC prevalence in rearing gilts can be influenced by dietary carbohydrates and / or arginine by affecting IGF-1, insulin, glucose, and nitric oxide (NO) levels. Gilts (n=212; Dutch Large White x Dutch Landrace) were acquired after weaning (4 weeks of age). At 6 weeks of age, gilts were subjected to a 2×2 factorial treatment design of dietary carbohydrate and arginine level scale fed at pen level. Carbohydrate level consisted of 12.5% cornstarch and 12.5% dextrose added to a basal diet (C+) versus an isocaloric diet in which cornstarch and dextrose were replaced with 8.9% soya bean oil (C-). Arginine supplementation consisted of 0.8% arginine supplemented to a basal diet (A+) versus 1.64% alanine as the isonitrogenous control (A-). At 24 weeks of age, blood samples of in total 34 gilts around feeding were taken and assessed for insulin, glucose, IGF-1, and NO levels. After slaughter at 25 weeks of age, OC was scored on the elbow, knee, and hock joints. Gilts in the C-treatment had higher glucose and insulin levels 90minutes after feeding onwards and higher IGF-1 levels than gilts in the C+treatment (P<0.05). Arginine supplementation did not significantly affect metabolic parameters. Arginine supplementation tended to decrease OC prevalence (P=0.07) at the animal level (all joints combined) and in the knee joint. Carbohydrate treatment affected prevalence of OC only in the knee joint in which gilts in the C-treatment had a higher odds ratio (OR) to have OC (OR = 2.05, CI: 1.18-3.58) than gilts in the C+treatment. Additionally, body weight at slaughter was significant when added to the statistical model (P<0.01) in the knee joint and the animal level (per 10kg increase OR=1.33, CI=1.11-1.6 and OR=1.17, CI=1.05-1.31, respectively). This study found effects of carbohydrates on OC prevalence in gilts at slaughter. The dietary treatment effects found in the current study likely have been mediated through effects on body weight.


      PubDate: 2016-04-12T15:37:14Z
       
  • Polymorphism in the SCD gene is associated with meat quality and fatty
           acid composition in Iranian fat- and thin-tailed sheep breeds
    • Abstract: Publication date: Available online 11 April 2016
      Source:Livestock Science
      Author(s): Mohsen Aali, Hosein Moradi-Shahrbabak, Mohammad Moradi-Shahrbabak, Mostafa Sadeghi, Hamid Kohram
      The enzyme stearoyl-coenzyme A-desaturase (SCD) has been proposed as a key regulator for fat content and fatty acid composition of meat. In this study, a DNA sequence and single-strand confirmation polymorphism analysis were performed in an attempt to investigate the relationship between variation within the SCD gene and fatty acid profiles, physicochemical composition, and the quality characteristics of longissimus dorsi (LD) muscle in two traditional fat- (Chall) and thin- (Zel) tailed Iranian sheep breeds. Only one previously reported SNP (g.379A>T) located in the 5′ untranslated region of the SCD gene was observed. Two previously reported allelic variants, SCD−1 and SCD−2, constituted two previously reported genotypes, “A” and “B”. Based on t-test, no allelic and genotypic frequency differences were observed between Chall and Zel breeds. Lambs with genotype “B” significantly had lower total saturated fatty acid (SFA) level (p<0.05) and more linoleic (p<0.02), arachidonic (p<0.002), and eicosapentaenoic (EPA) (p<0.001) acids and total poly-unsaturated fatty acid (PUFA) (p=0.002) contents and PUFA:SFA ratio (p<0.004) than those with genotype “A”. Meat color of the genotype “B” lambs was lower for a⁎ (p<0.05) and higher for L⁎ (p<0.08) compared to the genotype “A” ones. There were some interactions between breed and SCD gene in terms of palmitic acid (p<0.04), cooking loss (p<0.05), and protein content (p<0.03) of LD muscle. SCD locus explained 17.3%, 15.3%, 13%, and 12% of the phenotypic variation in terms of EPA and arachidonic acid, and PUFA contents and PUFA:SFA ratio, respectively. Interestingly, the results of the correlation analyses showed the significant negative correlations between healthy fatty acid indices (PUFA and PUFA:SFA) and meat color measures of a⁎ and b⁎ (r=−0.26 to r=−0.40, p<0.05) and the significant positive correlations between n−6:n−3 PUFA, one of the main harmful fatty acid indices, and a⁎ (r=0.41, p<0.01) and b⁎ (r=0.27, p<0.05) values which are coordinated with the effect of SCD genotypes on fatty acid composition and color of meat. So, both fatty acid composition and meat color traits should be considered in marker-assisted selection based on SCD gene. Overall, it seems that the genotype “B” of SCD gene is a more desirable genotype when selecting lambs in terms of both fatty acid composition and color of meat, because selecting this genotype would result in higher proportion of healthy fatty acids, lower proportion of harmful fatty acids, and better meat color.


      PubDate: 2016-04-12T15:37:14Z
       
  • Characteristics of runs of homozygosity in selected cattle breeds
           maintained in Poland
    • Abstract: Publication date: Available online 11 April 2016
      Source:Livestock Science
      Author(s): Tomasz Szmatoła, Artur Gurgul, Katarzyna Ropka-Molik, Igor Jasielczuk, Tomasz Ząbek, Monika Bugno-Poniewierska
      Runs of homozygosity (ROH) are defined as contiguous homozygous regions of the genome where the two haplotypes inherited from the parents are identical. It has been shown that the length and frequency of ROH may describe the history of the population in which an individual occurs; they may also reveal the level of inbreeding within populations, recent population bottlenecks or signatures of positive selection. In this study, BovineSNP50 whole-genome genotyping assay was used to analyse the lengths and distributions of the ROH found in the genomes of four cattle breeds maintained in Poland (Holstein, Polish Red, Limousin and Simmental) to assess both the level of autozygosity of each breed and to identify the genomic regions most commonly associated with ROH that may reflect directional selection pressure. Visible differences in the length and distribution of homozygous regions across the genome between selected breeds were observed. The breeds also varied in the level of autozygosity (inbreeding) estimated by FROH, which was lower for unselected cattle. Moreover, within the regions of the genome most commonly associated with ROH that may reveal signatures of recent selection a number of genes potentially connected with different production features characteristic for individual breeds were detected.


      PubDate: 2016-04-12T15:37:14Z
       
  • Enhancement of daily gain and feed efficiency of growing heifers by
           dietary supplementation of β-mannanase in Hanwoo (Bos taurus
           coreanae)
    • Abstract: Publication date: Available online 4 April 2016
      Source:Livestock Science
      Author(s): Jakyeom Seo, Jeongsoo Park, Junsung Lee, Jae-Hwan Lee, Jung-Jin Lee, Dong Keun Kam, Seongwon Seo
      β-mannanase is an enzyme that breaks down mannan which is complex biopolymers commonly found in plant cell walls. It has been reported that supplementation of β-mannanase in a diet that composed of high mannan containing feedstuffs (e.g. palm kernel meal, copra meal, soy hull; HMCF) improves digestibility and utilization of livestock feeds. In ruminants, β-mannanase supplementation also increased growth rate of goats and Holstein calves. No study, however, has been conducted to evaluate the effect of β-mannanase supplementation in growing heifers. Moreover, little is known whether β-mannanase supplementation will have beneficial effects in conventional corn-soy based diets (CS). The objective of this study was thus to investigate the effect of supplementation of β-mannanase in Hanwoo growing heifers fed a diet composed of either a CS or HMCF based concentrate mix. For this purpose, a feeding trial was conducted for 12 weeks using a total of 40 Hanwoo growing heifers (BW: 236.2kg±1.1kg, 11 month of age). Total mixed rations (250g/kg of ryegrass and 750g/kg of concentrate mix) were offered ad libitum. The experimental design was 2×2 factorial approach with two different concentrate mixes (CS or HMCF based) and with or without a commercial feed β-mannanase (800,000U/kg DM) product (CTCZYME®, CTC Bio Inc., Seoul, Korea) at a level of 1g/kg in concentrate mixes. In both diets, supplementation of β-mannanase significantly increased ADG of Hanwoo heifers by 95g/d on average (111g/d or 90g/d for CS and HMCF, respectively). No significant difference was observed in DMI among treatments, but β-mannanase supplementation tended to decrease feed conversion ratio (DMI/ADG) by 1.3 on average. The ADG of CS (943g/d) was significantly greater than that of HMCF (854g/d). These results indicated that supplementation of β-mannanase enhanced growth rate and feed efficiency of Hanwoo heifers regardless of the basal diets. Therefore, we conclude that supplementation of β-mannanase can be beneficial to improve the feed utilization in Hanwoo growing heifers.


      PubDate: 2016-04-07T04:54:53Z
       
  • Interaction of donor age, parity and repeated recovery of cumulus-oocyte
           complexes by ovum pick-up on in vitro embryo production and viability
           after transfer
    • Abstract: Publication date: Available online 6 April 2016
      Source:Livestock Science
      Author(s): Jong-In Jin, Nasser Ghanem, Seong-Su Kim, Byung-Hyun Choi, A-Na Ha, Kyeong-Lim Lee, Du-Won Sun, Hyun-Tae Lim, Jung-Gyu Lee, Il-Keun Kong
      The objective of this study was to investigate the effect of age and number of parities on the potential of the Korean native cow (Hanwoo breed) as oocyte donor in ovum pick-up and subsequent in vitro embryo production. All animals were divided into two different groups based on age (3-6 and 7-9 years) and parity (2-3 and 4-7). Ovum pick-up (OPU) was performed to ten Korean native cows over a 4-months period at intervals of 3-4 d (twice weekly). The population of follicles (≥ 3 mm diameter) present in both ovaries and the grades of all cumulus-oocyte complexes (COCs) retrieved were recorded. All COCs were matured, fertilized and allowed to develop in vitro and the morphological quality of embryos was evaluated before transfer to recipients. There were 18.4±5.7 (mean ± SEM) follicles available for aspiration throughout the experiments; the population of follicles decreased from 19.1±6.3 in the first month to 16.9±4.2 in the last month (p≤0.05). However, with advancement in age and parity of animals, there was an increase in number of ovarian follicles. Furthermore, the average number of COCs retrieved was 12.5±5.6 in the first month and this number was reduced in the fourth month (10.4±5.4). The total number of recovered COCs was increased in old cows with increased number of parities. Consequently, embryo production decreased from 4.8±3.1 to 4.2±2.8 on the first and last months, while, it was increased in old cows than young ones (p≤0.05). Furthermore, animals with high number of antral follicular count produced more COCs and embryos. Therefore, we concluded that repeated OPU of Korean native cows resulted in significant decrease in the in vitro production of embryos in young compared with old cows; this has negatively impacted embryo survival after transfer.


      PubDate: 2016-04-07T04:54:53Z
       
  • A complex of trypsin and chymotrypsin effectively inhibited growth of
           pathogenic bacteria inducing cow mastitis and showed synergistic
           antibacterial activity with antibiotics
    • Abstract: Publication date: Available online 28 March 2016
      Source:Livestock Science
      Author(s): X.H. Zhang, Z. Wang, B. Yin, H. Wu, S. Tang, L. Wu, Y.N. Su, Y. Lin, X.Q. Liu, B. Pang, N. Kemper, J. Hartung, E.D. Bao
      The objective of this research was to assess the inhibitory effects of a complex of trypsin and chymotrypsin alone and in combination with antibiotics, on pathogenic bacteria involved in cow mastitis in vitro. We also conducted investigations of the antimicrobial mechanism and primary treatment trials on infected cattle. The presence of trypsin (0.16mg/mL) alone only clearly hindered the growth of Streptococcus agalactiae (CVCC586) and Streptococcus dysgalactiae (ATCC12388). Chymotrypsin (0.16mg/mL) alone, and the complex of trypsin and chymotrypsin at the dose C (0.16mg/mL trypsin + 0.16mg/mL chymotrypsin) or 2C showed varying inhibitory effects on all the tested bacterial strains, including Escherichia coli (ATCC8739), Pasteurella (C51-3), Staphylococcus aureus (ATCC25923). The experiments also indicated that the complex of trypsin and chymotrypsin could hydrolyze bacterial outer-membrane proteins, damage the integrity of surface structures, and lead to leakage of intracellular material such as alkaline phosphatase, glucose and DNA. The complex of Trypsin and chymotrypsin showed well synergistic antibacterial effects when combined with specific antibiotics. In the field trial on 20 cows naturally suffering from clinical mastitis, the complex of trypsin and chymotrypsin reduced effectively Streptococcus, E. coli, S. aureus, and some other Enterobacteriaceae as well as the somatic cell counts in milk samples of treated cattle compared to controls. The complex of trypsin and chymotrypsin, and its combination with antibiotics, seems to have a potential in clinical veterinary medicine to treat mastitis.


      PubDate: 2016-04-03T04:36:01Z
       
  • Technical Note: Can tail arterial or tail venous blood represent external
           pudic arterial blood to measure amino acid uptake by mammary gland of
           cows?
    • Abstract: Publication date: Available online 1 April 2016
      Source:Livestock Science
      Author(s): Y.D. Zhang, D.P. Bu, S.C. Li, N. Zheng, X.Q. Zhou, M. Zhao, S.G. Zhao, S.L. Li, J.Q. Wang
      Sampling blood from the artery supply and venous drainage of the udder of dairy cows is essential for estimating the uptake of amino acids (AA) by the mammary gland using the arteriovenous difference approach. Since it is difficult to sample blood form the external pudic artery, finding a representative alternative was necessary. In this experiment, 13 lactating Holstein dairy cows were used to validate whether blood from the tail artery or tail vein could be used a substitute for external pudic arterial blood for calculation of amino acid (AA) extraction rate by the mammary gland. The results showed that no significant differences were noted in the individual AA concentration (P>0.10) between the tail arterial, tail venous blood and external pudic artery, except for Asp, Thr and Pro. The calculated extraction rates based on the A-V difference between the external pudic artery, tail artery or tail vein and the subcutaneous vein were not different for individual AA (P>0.10) except for those rates for Asp, Thr and Glu (P<0.10). These results indicated that blood sample from the tail artery or tail vein could be used as an alternative to external pubic arterial blood for studying the uptake of most AA, but not for Asp, Thr and Glu, by the mammary gland of dairy cows.


      PubDate: 2016-04-03T04:36:01Z
       
  • Enteric methane emissions and nitrogen utilisation efficiency for two
           genotype of hill hoggets offered fresh, ensiled and pelleted ryegrass
    • Abstract: Publication date: Available online 31 March 2016
      Source:Livestock Science
      Author(s): Y.G. Zhao, A. Aubry, R. Annett, N.E. O’Connell, T. Yan
      Thirty-six 12-month-old hill hoggets were used in a 2 genotype (18 Scottish Blackface vs. 18 Swaledale × Scottish Blackface)×3 diet (fresh vs. ensiled vs. pelleted ryegrass) factorial design experiment to evaluate the effects of hogget genotype and forage type on enteric methane (CH4) emissions and nitrogen (N) utilisation. The hoggets were offered 3 diets ad libitum with no concentrate supplementation in a single period study with 6 hoggets for each of the 6 genotype × diet combinations (n=6). Fresh ryegrass was harvested daily in the morning. Pelleted ryegrass was sourced from a commercial supplier (Aylescott Driers & Feeds, Burrington, UK) and the ryegrass silage was ensiled with Ecosyl (Lactobacillus plantarum, Volac International Limited, Hertfordshire, UK) as an additive. The hoggets were housed in individual pens for at least 14 d before being transferred to individual respiration chambers for a further 4 d with feed intake, faeces and urine outputs and CH4 emissions measured. There was no significant interaction between genotype and forage type on any parameter evaluated. Sheep offered pelleted grass had greater feed intake (e.g. DM, energy and N) but less energy and nutrient apparent digestibility (e.g. DM, N and neutral detergent fibre (NDF)) than those given fresh grass or grass silage (P<0.001). Feeding pelleted grass, rather than fresh grass or grass silage, reduced enteric CH4 emissions as a proportion of DM intake and gross energy (GE) intake (P<0.01). Sheep offered fresh grass had a significantly lower acid detergent fibre (ADF) apparent digestibility, and CH4 energy output (CH4-E) as a proportion of GE intake than those offered grass silage (P<0.001). There was no significant difference, in CH4 emission rate or N utilisation efficiency when compared between Scottish Blackface and Swaledale × Scottish Blackface. Linear and multiple regression techniques were used to develop relationships between CH4 emissions or N excretion and dietary and animal variables using data from sheep offered fresh ryegrass and grass silage. The equation relating CH4-E (MJ/d) to GE intake (GEI, MJ/d), energy apparent digestibility (DE/GE) and metabolisability (ME/GE) resulted in a high r2 (CH4-E=0.074 GEI + 9.2 DE/GE – 10.2 ME/GE – 0.37, r2=0.93). N intake (NI) was the best predictor for manure N excretion (Manure N=0.66 NI + 0.96, r2=0.85). The use of these relationships can potentially improve the precision and decrease the uncertainty in predicting CH4 emissions and N excretion for sheep production systems managed under the current feeding conditions.


      PubDate: 2016-04-03T04:36:01Z
       
  • DNA-based analysis of protein variants reveals different genetic
           variability of the paralogous equine ß-lactoglobulin genes LGB1 and
           LGB2
    • Abstract: Publication date: Available online 23 March 2016
      Source:Livestock Science
      Author(s): J. Brinkmann, V. Jagannathan, C. Drögemüller, S. Rieder, T. Leeb, G. Thaller, J. Tetens
      The genetic variability of milk protein genes may influence the nutritive value or processing and functional properties of the milk. While numerous protein variants are known in ruminants, knowledge about milk protein variability in horses is still limited. Mare's milk is, however, produced for human consumption in many countries. Beta-lactoglobulin belonging to the protein family of lipocalins, which are known as common food- and airborne allergens, is a major whey protein. It is absent from human milk and thus a key agent in provoking cow's milk protein allergy. Mare's milk is, however, usually better tolerated by most affected people. Several functions of β-lactoglobulin have been discussed, but its ultimate physiological role remains unclear. In the current study, the open reading frames of the two equine β-lactoglobulin paralogues LGB1 and LGB2 were re-sequenced in 249 horses belonging to 14 different breeds in order to predict the existence of protein variants at the DNA-level. Thereby, only a single signal peptide variant of LGB1, but 10 different putative protein variants of LGB2 were identified. In horses, both genes are expressed and in such this is a striking previously unknown difference in genetic variability between the two genes. It can be assumed that LGB1 is the ancestral paralogue, which has an essential function causing a high selection pressure. As horses have very low milk fat content this unknown function might well be related to vitamin-uptake. Further studies are, however, needed, to elucidate the properties of the different gene products.


      PubDate: 2016-03-29T04:29:34Z
       
  • Genetic characterization of the endangered Gochu Asturcelta pig breed
           using microsatellite and mitochondrial markers: insights for the
           composition of the Iberian native pig stock
    • Abstract: Publication date: Available online 22 March 2016
      Source:Livestock Science
      Author(s): Juan Menéndez, Félix Goyache, Albano Beja-Pereira, Iván Fernández, Nuria A. Menéndez-Arias, Raquel Godinho, Isabel Álvarez
      The extremely endangered Gochu Asturcelta pig breed was analysed to document its genetic background and to ascertain if the traditional classification of native pig of the Iberian Peninsula into the Celtic-Iberian and the Iberian groups has genetic support. Two populations of Gochu Asturcelta pig (initial and present, including 31 and 124 individuals, respectively) were typed for 17 microsatellites together with 137 individuals of four domestic pig populations (eight breeds) and Wild Boar. Gochu Asturcelta populations showed a noticeable genetic distance with the other populations analysed due to the extreme bottleneck suffered by the breed. In any case, differentiation between the two Gochu Asturcelta populations analysed was very low (FST=0.021±0.005). Moroever, the two Gochu Asturcelta populations took basically the same values (1.14 and 1.13, respectively) for parameter N g (founder genome equivalents) suggesting that the Gochu Asturcelta breed has not suffered additional genetic losses of genetic variability due to drift after the implementation of the breeding scheme. A total of 174 mtDNA control region fragments (647bp) were analysed allowing the identification of 30 different haplotypes. Gochu Asturcelta had only three different haplotypes. The most frequent haplotypes H3 (18% of the samples; assigned to Larson et al.’s haplogropup A) and H5 (25% of the samples; assigned to Larson et al.’s haplogropup C) could be identified in all the Celtic-Iberian, Iberian and Cosmopolitan pig breeds analysed. This makes difficult to ensure that the classical hypothesis explaining different origins for the native pig strains of the Iberian Peninsula has genetic support. Projection of the mitochondrial DNA genetic variability (summarised via Principal Component Analysis) on geographical maps informed that the mtDNA composition of domestic pig native of the Iberian Peninsula depicts the recent rather than the ancient history of the analysed populations.


      PubDate: 2016-03-23T13:01:01Z
       
  • Analysis of polymorphisms in the equine MSTN gene in Polish populations of
           horse breeds
    • Abstract: Publication date: Available online 21 March 2016
      Source:Livestock Science
      Author(s): Monika Stefaniuk, Katarzyna Ropka-Molik, Katarzyna Piórkowska, Maria Kulisa, Zenon Podstawski
      Myostatin (encoded by MSTN gene) also called GDF-8, belongs to the TGF-β super family of growth and differentiation factors. Myostatin protein acts as a strong inhibitor of muscle formation. In Thoroughbred horses MSTN polymorphism g.66493737T>C is associated with racing phenotypes and body compositions. The aim of the present study was to examine the occurrence of MSTN variants among four polish breeds (in total 348 horses): Arabians, Polish Konik, Hucul and Polish Heavy Draft, distribution of haplotypes among these breeds, and finally influence of investigated polymorphisms on height at the withers in Arabian horses (n=96). Results showed occurrence of five SNPs: g.66495826T>C, g.66495696T>C, g.66493737T>C, g.66495254C>T, g.66490010T>C previously described. Furthermore, influence of investigated polymorphisms on height at the withers during growth in Arabian horses revealed significant impact of g.66495696T>C polymorphism on height at the withers at the first 12hours of life. On the other hand, heterozygous foals are higher and this trend has been observed from six to 36 month of life.


      PubDate: 2016-03-23T13:01:01Z
       
  • Non-invasive measures of oral-rectal transit in young pigs
    • Abstract: Publication date: Available online 18 March 2016
      Source:Livestock Science
      Author(s): Andre Y.F. Tan, Magdy Sourial, John M. Hutson, Bridget. R. Southwell
      The gastrointestinal transit of markers in pigs has been well studied, but the methods and approaches are different from gastrointestinal studies performed in humans clinically. Aim: To develop a non-invasive method of estimating oral-rectal transit times in young pigs. Methods: We performed transit studies in 3 groups of 4 week-old, Large White female pigs. Group 1. Ten animals (5.7±0.34kg (mean ± SEM)) were fed blue-dyed grower feed and placed under video surveillance. Group 2a. Twenty-two animals (7.7±0.59kg) from the same pig supplier were administered 18 4mm-diameter radio-opaque plastic markers under light anaesthesia (5% isofluorane), and we took abdominal x-rays at 6, 30, 54 and 78hours. Group 2b. Eight pigs (9.2±0.48kg) from a different supplier also underwent plastic marker transit studies. Results: Using blue dye (fluid transit), the median (25th, 75th percentiles) time to first incidence of blue-dyed stool was 13.2 (10.2, 18.1) hours and to last blue stool was 24.1 (22.4, 40.3) hours. Using plastic markers, markers were evacuated between 30 and 80+hours with differences in stomach emptying between two groups of animals from different farms. Median oral-rectal transit times were 25.2 (17.8, 40.5) hours and 48.9 (26.9, 68.3) hours in the second and third groups (M-W test, P=0.04). Conclusion: There are differences in the transit of fluid- and solid-phase marker in pigs. Fluid-phase markers appear earlier than solid markers. Monitoring the evacuation of fluid-phase dye using video surveillance is difficult. Using plastic markers and x-rays to estimate the segmental and oral-rectal transit times in young pigs may be a useful method that can be correlated to oral-rectal transit studies performed in humans. The ability of pigs to hold solids in the stomach for extended times complicates transit studies. There are some differences in transit in pigs from different breeders.


      PubDate: 2016-03-23T13:01:01Z
       
  • Lactation and reproductive performance of high producing dairy cows given
           sustained-release multi-trace element/vitamin ruminal bolus under heat
           stress condition
    • Abstract: Publication date: Available online 15 March 2016
      Source:Livestock Science
      Author(s): Simin Khorsandi, Ahmad Riasi, Mohammad Khorvash, Saeid Ansari Mahyari, Farhad Mohammadpanah, Farhad Ahmadi
      The aim of the study was evaluation the effect of sustained-release multi-trace element/vitamin bolus on blood metabolite and performance of Holstein dairy cows reared under heat stress conditions. Maximum temperature humidity index (THI) was 77.7 during the trial. Fifty multiparious cows were randomly allocated to two experimental groups: 1-bolus supplemented cows (Treatment), and 2-no bolus (Control). Each bolus contained minerals (16.2g Cu, 0.251g Se, 0.236g Co, 0.497g I, 8.28g Mn and 13.32g Zn) and vitamins (545.6×103 IU of vitamin A, 109.1×106 IU of vitamin D3 and 1092 IU of vitamin E). Results showed that cows supplemented with bolus tended to have higher milk yield (P=0.07), milk fat (P=0.03), protein (P<0.001), and solid non fat (SNF) (P<0.001) percentage compared to control. Bolus supplementation decreased the milk linear somatic cell count (SCC) score (P=0.01). Cows administered bolus tended to have lower plasma non-esterified fatty acids (NEFA) in the postpartum period (P=0.09). Days open (calving to conception) was shortened in response to bolus supplementation (P=0.02). Cumulative pregnancy at fifth artificial insemination was significantly increased in response to treatment (P=0.01). It was concluded that supplementation trace elements and vitamins above National Research Council (NRC) recommendation using a sustained release source had positive effects on reproductive and lactation performance of high producing dairy cows kept under heat stress condition.


      PubDate: 2016-03-18T11:56:43Z
       
  • Avoiding double counting when deriving economic values through stochastic
           dairy herd simulation
    • Abstract: Publication date: Available online 8 March 2016
      Source:Livestock Science
      Author(s): Søren Østergaard, Jehan Frans Ettema, Line Hjortø, Jørn Pedersen, Jan Lassen, Morten Kargo
      It has been a challenge to avoid double counting when economic values (EV) of traits are derived for breeding goal traits when using stochastic herd simulation models. In this study multiple regression and model building with mediator variables representing other traits in the breeding goal were evaluated to avoid double counting. EV were derived from data simulated with the SimHerd dairy herd simulation model. Scenarios were simulated to represent dairy herds with low and high levels of metritis and cow mortality. The simulated data was analyzed statistically with the economic net return per cow-year as the dependent variable and either the incidences of metritis or the incidence of cow mortality as the independent variables. In the model with metritis we corrected for mediator variables representing the direct effects of metritis on milk yield, fertility and occurrence of other diseases. The EV was estimated as the marginal change in economic net return in response to a change in the trait of interest. To avoid the multiple regression models to correct the EV for structural herd effects (changes in distribution of parities and lactation stages) we used a single animal based indicator variable for each trait of interest, such as incidence rate of cow mortality 1 to 100 DIM in multiparous cows. The EV value of improving the trait ‘incidence rate of metritis 1 to 100 DIM in multiparous cows’ by 0.01 was estimated to be €0.93. The importance of avoiding double counting was demonstrated as the EV of metritis was overestimated by 82% when no mediator variables were included in the multiple regression analysis. And by ignoring structural herd effects for the EV of metritis we demonstrated an underestimation in the order of 9%. Further pitfall of underestimation was demonstrated for EV of cow mortality. The EV of improving the trait ‘incidence rate of cow mortality 1 to 100 DIM in multiparous cows’ by 0.01 was estimated to be €46.4. Correcting for the independent variation in mortality between simulation replicates within the individual scenarios was found to be important. The results of this study suggests a new method for designing simulation experiments and analyzing simulated herd effects for estimation of EV of traits in a breeding goal. This deals with a number of previous and new concerns of how to correct for double counting and at the same time still include the structural herd effects.


      PubDate: 2016-03-13T11:52:50Z
       
  • Impact of phenotypic information of previous generations and depth of
           pedigree on estimates of genetic parameters and breeding values
    • Abstract: Publication date: Available online 2 March 2016
      Source:Livestock Science
      Author(s): Hui Yang, Guosheng Su
      Reliability of estimated breeding values (EBV) depends on amount of information in both phenotypic data and pedigree data. This study investigated the impact of phenotypic information of previous generations and depth of pedigree on estimates of genetic parameters and breeding values in populations of polytocous animals such as pig. Three populations which mimicked pig populations were generated. The animals were selected on a selection index including two traits (h2=0.35 for trait 1 and h2=0.10 for trait 2). Variance components and breeding values were estimated using different phenotypic data and pedigree data which cover different numbers of previous generations. Impact of phenotypic information of previous generations and depth of pedigree on EBV was evaluated by reliability of EBV for animals in the last generation (as candidates for breeding). Phenotypic data or pedigree data covering various numbers of previous generations led to different estimates of additive genetic variance (larger variance when earlier generations were included), especially for trait 1, because conceptual base populations were different in different data sets. Information from previous generations was more important for reliability of EBV of trait 2 than that of trait 1, and the contribution of previous phenotypic information to reliability of EBV was larger in the population with smallest sib group than the population with the largest sib group. According to the current study, phenotypic data including recent three to five generations and pedigree data added one to three ancestral generations will lead to asymptotic maximum reliability of EBV for animals in current population, dependent on population structure and heritability of trait. The results indicate: 1) In general, three generations of records plus two ancestral generations in pedigree is enough for predicting breeding values with regard to accuracy of EBV; 2) Variance components used for genetic evaluation should be estimated from the data set that is consistent with the data set for predicting breeding values with regard to conceptual base population; 3) In order to increase reliability of EBV in a polytocous animal population such as pig, the efficient approach is to measure the animals available within generation as many as possible so as to fully use information from sibs, instead of more data from early generations.


      PubDate: 2016-03-08T11:44:17Z
       
  • Population structure of Tabapuã beef cattle using pedigree analysis
    • Abstract: Publication date: Available online 7 March 2016
      Source:Livestock Science
      Author(s): P.A. Bernardes, D.A. Grossi, R.P. Savegnago, M.E. Buzanskas, S.B. Ramos, E.P. Romanzini, D.G.F. Guidolin, L.A.F. Bezerra, R.B. Lôbo, D.P. Munari
      This study evaluated a Tabapuã population structure and the linear relationship of the inbreeding coefficient with phenotypic values of weaning weight adjusted to 210 days of age (W210); age at first calving (AFC); first (CI1), second (CI2) and average (ACI) calving intervals; and, accumulated productivity (ACP). The phenotypic data used were from 7,340 cows and the pedigree file had 15,241 animals. The average pedigree completeness of the last six generations was 47.99%. The effective numbers of founders and ancestors were 124 and 110, respectively, with a ratio of 1.13. These results suggested the absence of the genetic bottleneck effect. The inbreeding coefficient increased over generations and the average was 0.007. The effective population size became small in the last generation. The regression analysis results of phenotypic values for inbreeding coefficients were not significant (P>0.05) for W210, CI1 and ACP; and, significant (P<0.05) and favorable for AFC, ACI and CI2. The results indicated that mating between related animals and the intensive use of few breeders should be avoided. Regression analysis indicated no inbreeding depression, which can be justified by the fact that inbreeding is not yet strongly established.


      PubDate: 2016-03-08T11:44:17Z
       
  • Dose response of chitosan on nutrient digestibility, blood metabolites and
           lactation performance in holstein dairy cows
    • Abstract: Publication date: May 2016
      Source:Livestock Science, Volume 187
      Author(s): R.D. Mingoti, J.E. Freitas, J.R. Gandra, R. Gardinal, G.D. Calomeni, R.V. Barletta, T.H.A. Vendramini, P.G. Paiva, F.P. Rennó
      Chitosan (CHI), a non-toxic and biodegradable biopolymer has been successfully used in the food, human and veterinary medicine industries, especially because of its antimicrobial properties. This study aimed to investigate the effects of CHI on dry matter intake (DMI), nutrient digestibility, blood metabolites, milk yield and composition, and milk fatty acids profile of lactating dairy cows. Sixteen Holstein cows (91.3±15.1 days in milk, 29.8±4.1kg/d of milk, 610±55kg of body weight [BW]) were used in a 4×4 Latin square design, and each experimental period consisted of 14 days of diet adaptation and 7 days for data collection. Animals were allocated to receive one of treatments: C0: basal diet, without CHI addition; C50, C100 and C150 received 50, 100 and 150mg/kg BW of CHI, respectively. Chitosan addition did not affect DMI, but increased (P≤0.05) the digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fiber (NDF). Blood urea nitrogen concentration was increased (P=0.01) with CHI addition. Chitosan decreased (P=0.02) nitrogen (N) fecal excretion without affect nitrogen balance. There was no effect of CHI on milk yield, fat corrected milk, and milk composition. Chitosan decreased (P≤0.05) C6:0 and C18:1 c9, and quadratically affected C14:1 fatty acids (FA) concentration in milk fat. Chitosan had no effect on total saturated and unsaturated FA of milk fat. Chitosan improved nutrient digestibility without affect productive performance and milk fatty acid profile of mid-lactation dairy cows.


      PubDate: 2016-03-08T11:44:17Z
       
  • A Genome-wide association study to identify chromosomal regions
           influencing ovine cortisol response
    • Abstract: Publication date: Available online 22 February 2016
      Source:Livestock Science
      Author(s): Sameer D. Pant, Qiumei You, Laila C. Schenkel, Gordon Vander Voort, Flavio S. Schenkel, Jim Wilton, Laura Cain, Niel A. Karrow
      Stress-induced hypothalamic-pituitary-adrenal axis (HPAA) activation and subsequent glucocorticoid production has a significant impact on behavior, metabolism and immune function in both humans and animals. Therefore, elucidating functional mechanisms that regulate stress-induced glucocorticoid production would benefit the development of alternative and improve existing treatment and management strategies supporting animal health. Animal studies have demonstrated considerable variation in stress-induced cortisol responses, and the phenotype appears to be moderately-to-highly heritable. Therefore, the objective of the current study was to identify key genetic determinants that putatively influence the ovine cortisol response to a bacterial endotoxin-induced stress (BEIS) model. The ovine50K BeadChip containing 54,241 single nucleotide polymorphisms (SNPs) was used to selectively genotype 75 sheep with high (HCR) and low cortisol responses (LCR) (38 HCR and 37 LCR). The selective genotyping approach yielded statistical power equal to roughly 190 randomly genotyped animals. A statistical analysis was performed via a univariate logistic regression model and a total of 16 SNPs were identified to be significantly associated with the cortisol levels in this population. These SNPs were grouped, based on proximity on the same chromosome, into 13 chromosomal regions that harbored 9 ovine RefSeq genes. Although the ovine genome is not well annotated, important genes such as CD14, ITGAM, SNX2 and ITGAL were found to reside within the identified QTLs. A positional candidate gene approach was also used subsequently to identify three novel SNPs in SNX2, and one of these SNPs (ss974768716) was found to be significantly associated with the cortisol response phenotype (p=0.017). A brief description of the ovine BEIS population, statistical analyses and identified genes is presented herein.


      PubDate: 2016-02-26T15:28:17Z
       
  • Rumen papillae morphology of beef steers relative to gain and feed intake
           and the association of volatile fatty acids with kallikrein gene
           expression
    • Abstract: Publication date: Available online 23 February 2016
      Source:Livestock Science
      Author(s): R.J. Kern, A.K. Lindholm-Perry, H.C. Freetly, L.A. Kuehn, D.C. Rule, P.A. Ludden
      Feed costs are the most expensive input in beef production. Improvement in the ability of beef cattle to convert feed into meat would lower feed inputs and reduce the cost of production. The rumen epithelium is responsible for absorption and metabolism of nutrients and microbial by-products, and may play a significant role in gain or feed intake. Our objective was to determine the relationships among rumen papillae morphology, gene expression, volatile fatty acid concentrations, and gain and feed intake. Average daily gain (ADG) and average daily feed intake (ADFI) were collected on a crossbred population of beef steers over three feeding trials. Based on feed intake and weight gain differences, 48 steers were selected for the project (16 from each feeding study). At harvest, rumen epithelial samples were taken from three locations in the rumen of each animal. The number of papillae on 1cm2 of epithelium was counted to determine density. Papillae (n=30) from each sample were measured for length and width. The density, length, and width were combined to determine surface enlargement factor (SEF). None of the morphological characteristics of the papillae (length, width, density or SEF) were associated with feed intake or gain (P≥0.10). Ruminal fluid was collected from steers (n=15) in the third trial for volatile fatty acid (VFA) analysis to determine if a relationship between VFA and ADG or ADFI existed. No differences in volatile fatty acid (VFA) concentrations were associated (P≥0.17) with ADFI or ADG. VFA variation was also evaluated for a relationship with kallikrein (KLK) genes since ruminal butyrate concentrations have previously been associated with the transcript abundance KLK genes. Additionally, qRT-PCR data showed that variation in the transcript abundance of KLK6,8-10, and 13 associated with feed intake in our first trial of steers. Thus, we evaluated the transcript abundance of eight KLK genes in rumen papillae from steers in the third trial (n=16). Expression levels of KLK5 correlated with valerate concentrations in the rumen (P<0.05), KLK10 correlated with acetate concentrations in the rumen (P<0.05), KLK12 correlated with acetate and butyrate concentrations in the rumen (P<0.05), and the expression levels of KLK9 and KLK10 were associated with gain. While rumen papillae morphology was not associated with beef steer gain or intake, our data suggests members of the kallikrein gene family have a relationship with the VFA environment in the rumen, and also appear to play a role in the highly correlated traits of ADG and ADFI.


      PubDate: 2016-02-26T15:28:17Z
       
  • Effects of rumen-protected niacin on milk production and body temperature
           of middle and late lactation holstein cows
    • Abstract: Publication date: Available online 17 February 2016
      Source:Livestock Science
      Author(s): A. Pineda, J.K. Drackley, J. Garrett, F.C. Cardoso
      The aim of this study was to evaluate the effect of rumen-protected niacin (RPN) supplementation during summer months on vaginal temperature, milk production, and milk composition of dairy cows. The study was conducted as switchback design constituted of 3 consecutive 3-week periods. Fifty lactating multiparous Holstein cows>100 days in milk were randomly assigned to one of two treatments groups. Dietary treatments were: (1) control diet (CON; n=25), not supplemented with RPN and (2) supplemented diet (RPN; n=25), supplemented with RPN (15g/cow daily). Both diets were fed for ad libitum intake 3X daily. Cows remained in the study for 9 weeks. Temperature humidity index (THI) was calculated with ambient temperature and relative humidity recorded throughout the study. Vaginal temperature was recorded during week 3, 6, and 9. Body weight (BW) and body condition score (BCS) were measured weekly. Milk production was recorded daily. Milk samples collected twice weekly in week 3, 6, and 9 were analyzed for fat, protein, lactose, urea nitrogen, and somatic cell count. Data were analyzed using the MIXED procedure of SAS (v9.4). Two statistical analyses were performed: (1) all experimental periods (mean THI=67) and (2) period two only (mean THI=72). Diets with similar chemical-nutritive composition were fed though the study. Ambient conditions were similar for both treatments but different across periods. Analysis one revealed no effect of RPN on vaginal temperature. Supplementation of RPN did not increased milk yield, whereas milk fat concentration was higher in RPN cows. Analysis two revealed lower (P=0.01) highest vaginal temperature by day (24h period) and nighttime period (1900–0459h) in RPN cows. Mean vaginal temperature at nighttime tended to be lower (P=0.07) for RPN as well. Milk fat concentration was greater in RPN than CON cows, but milk yield was similar across treatments. However, trends towards increased milk yield were observed in RPN cows during the period of higher temperatures and higher mean THI. In both analysis BW and BCS were unaffected by RPN supplementation. Supplementation of RPN increased milk fat concentration but had no effect on milk yield. However, in the period of higher ambient temperature and higher mean THI trends towards greater milk yield and lower vaginal temperatures were observed in RPN supplemented cows.


      PubDate: 2016-02-20T09:14:40Z
       
  • Effects of an enzyme cocktail on digestible and metabolizable energy
           concentrations in barley, corn, and wheat fed to growing pigs
    • Abstract: Publication date: Available online 11 February 2016
      Source:Livestock Science
      Author(s): Chan Sol Park, Inkyung Park, Beob Gyun Kim
      The objective of this study was to determine the effects of an enzyme cocktail (EC), consisting of xylanase, mannanase, and protease, on digestible energy (DE) and metabolizable energy (ME) concentrations in barley, corn, and wheat fed to growing pigs. A pilot study was conducted to determine the effects of EC on the in vitro ileal dry matter digestibility (IVDMD) in 8 sources of feed ingredient including barley, corn, wheat, canola meal, copra meal, cottonseed meal, palm kernel meal, and soybean meal. The IVDMD was determined in each feed ingredients with or without the 0 or 10g/kg of EC addition. The values for the IVDMD in barley and wheat increased (P<0.05) when the EC was added. However, the EC addition did not affect IVDMD of corn, canola meal, copra meal, cottonseed meal, palm kernel meal, and soybean meal. Based on the pilot study, an animal experiment was conducted to determine the effects of the EC on DE and ME concentrations in barley, corn, and wheat. A 3×2 factorial treatment arrangement with 3 ingredients and 0 or 2g EC/kg was used. Six barrows with 35.8±3.3kg body weight were assigned to 6 dietary treatments in a 6×6 Latin square design. There was no interaction between the ingredient and the EC addition, and the effect of the EC addition was not observed. The apparent total tract digestibility of gross energy in diets containing corn was greater (P<0.05) than diets containing barley, but was less (P<0.05) than diets containing wheat. The concentration of DE in barley, corn, and wheat were 3197, 3376, and 3503kcal/kg (as-fed basis), respectively, and the respective values of ME were 3035, 3304, and 3407kcal/kg (as-fed basis). In conclusion, the DE and ME concentrations in barley, corn, and wheat were not affected by the EC addition.


      PubDate: 2016-02-15T08:50:56Z
       
  • Natural gastro properties of ficus natalensis, Rhuss natalensis and
           Harrisonia abyssinica in native east african goats
    • Abstract: Publication date: Available online 6 February 2016
      Source:Livestock Science
      Author(s): Dorothy Kalule Nampanzira, John David Kabasa, Constantine Bakyusa Katongole, Sam Okello, John Robert Stephen Tabuti
      The natural gastro properties of Ficus natalensis, Rhuss natalensis and Harrisonia abyssinica was evaluated with the objectives of determining the rumen degradation properties. Results showed that H. abyssinica presented the highest DM disappearance from the nylon bags throughout the different incubation times followed by F. natalensis and R. natalensis showed the lowest. The DM readily available soluble fraction (a), insoluble but degradable fraction (b), degradation rate (c), potential degradability (PD) and effective degradability (ED) differed significantly (P<0.05) across the three browse species. The CP a, b, PD and ED fractions differed significantly (P<0.05) across the three browse species. The CP c fraction was similar across the browse species. The NDF a, b, PD, and ED fractions differed significantly (P<0.05) across the browse species. The NDF c fraction was not different across the browse species. In conclusion, Rhuss natalensis subsp. romantica has inferior rumen degradability properties, an indication of low nutritive value for goats compared to Harrisonia abyssinica subsp. abyssinica and Ficus natalensis subsp. Natalensis.


      PubDate: 2016-02-11T08:44:22Z
       
  • Structure and genetic diversity of Brazilian Zebu cattle breeds assessed
           by pedigree analysis
    • Abstract: Publication date: Available online 11 February 2016
      Source:Livestock Science
      Author(s): M.L. Santana, R.J. Pereira, A.B. Bignardi, D.R. Ayres, G.R.O. Menezes, L.O.C. Silva, G. Leroy, C.H.C. Machado, L.A. Josahkian, L.G. Albuquerque
      The monitoring of population structure, inbreeding and other related parameters has great potential to prevent major losses of genetic diversity in populations of Zebu cattle in Brazil. Therefore, the objective of the present study was to investigate the structure and genetic diversity of Brazilian Zebu cattle breeds by pedigree analysis. The national pedigree file of the seven Brazilian Zebu breeds was used, which included all registered animals (12,290,243) born between 1938 and 2012: Brahman, Gir, Guzerá, Indubrasil (IND), Nelore, Sindi (SIN), and Tabapuã. Almost all breeds studied undergo expansion in their census which, however, is not accompanied by the maintenance of genetic diversity. Problems were encountered in all breeds, but most of them can currently be considered less important. Using the calculation method considered as the most accurate for pedigree analysis when some population substructure exists, all breeds, except SIN, had effective population size greater than 100. The most common problems were the presence of tight bottlenecks in the pedigree, which were mainly due to the intensive use of few animals as parents and the high degree of population subdivision. The use of a wider range of sires is therefore recommended. However, most Zebu breeds can deal with breeding programs using high selection intensities. Greater care should be taken in the case of the IND breed since its census was reduced drastically over the last few years, a fact favoring the occurrence of serious problems related to inbreeding. Although SIN presents problems due to subdivision and possesses a relatively small census compared to other Zebu breeds, this population would have a promising future if its breeding policy were revised.


      PubDate: 2016-02-11T08:44:22Z
       
 
 
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