Livestock Science最新文献

{"title":"Impact of feed efficiency on young beef animals on adult resilience: From field challenge experiments to modelling approaches","authors":"P. Martin ,&nbsp;N.C. Friggens ,&nbsp;A. Vinet ,&nbsp;D. Dozias ,&nbsp;D. Maupetit ,&nbsp;G. Renand ,&nbsp;D. Villalba","doi":"10.1016/j.livsci.2024.105558","DOIUrl":"10.1016/j.livsci.2024.105558","url":null,"abstract":"<div><p>The relationship between feed efficiency at young ages and resilience as cows has been examined using an experiment that combines residual feed intake (RFI) evaluation of beef heifers and subsequent dietary challenge as cows. Feed efficiency of 569 heifers of 22 months of age was estimated during a 70-day period. Then a dietary challenge was applied on 303 of these animals after their first calving, half of them being fed 30 % below their expected needs from 10 days after calving up to the start of the grazing period (around mid-April), after which all the animals received the same management. When possible, the animals were kept until third lactation, giving a total of 514 lactations. Dam weight, dam BCS and calf weight were measured regularly, dam milk production was estimated three times during the lactation and resumption of cyclicity was recorded as well. The experimental data were analyzed using linear models including the effects of heifer efficiency (RFI &lt;-0.4 = efficient; RFI &gt;0.4 = inefficient) and interaction of heifer efficiency and diet group. The data were also used to calibrate a herd dynamics model representing management-nutrition and reproduction interactions at animal level. The experiment data showed that the efficient heifers were 18 kg heavier as cows when fed ad libitum (<em>P</em> = 0.04) but no difference was observed when restricted. Within both diets, heifers classified as efficient produced between 6 and 12 % less milk as cows than inefficient heifers depending on the lactation stage (<em>P</em> &lt; 0.01), with a subsequent effect on calf weight. Finally, the resumption of cyclicity was one week shorter for the efficient animals when fed <em>ad libitum</em> but the opposite was observed within the restricted group, representing a complete ovarian cycle difference between diet groups within the efficient class (<em>P</em> = 0.001). In the lifetime modelling approach, two clusters of animals with different characteristics, including RFI, were simulated under both a non-restricted and restricted feeding environment. In this simulation, efficient heifers produced lighter cows with lower intake and higher body reserves from second calving until culling. Non-efficient heifers had better productive (kg of weaned calf) performance as cows independently of environment. The simulated reproductive performance of cows was equal for animals coming from efficient and non-efficient heifers under the non-restricted environment whereas efficient heifers perform better in the restricted environment, especially when parity increases. Both approaches showed that the interplay between efficiency at young ages and short- and long-term resilience depends on the environment. It can be concluded that the selection for efficiency at young ages has a negative impact on lactational performance as cows but not necessarily on reproductive resilience.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"289 ","pages":"Article 105558"},"PeriodicalIF":1.8,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001641/pdfft?md5=edda42411564c037def69e19b3790864&pid=1-s2.0-S1871141324001641-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meeting ethological needs – Effects of straw and roughage on attractiveness of outdoor run and behaviour of organic fattening pigs","authors":"Guilherme Amorim Franchi,&nbsp;Tine Rousing,&nbsp;Lene Juul Pedersen","doi":"10.1016/j.livsci.2024.105554","DOIUrl":"10.1016/j.livsci.2024.105554","url":null,"abstract":"<div><p>Organic pigs must have permanent access to an open-air space, which typically consists of a barren concrete outdoor run. One way to improve the attractiveness of the outdoor run for pigs and facilitate the establishment of functional zones is through allocation of rooting or roughage materials in this pen area. Accordingly, we investigated the effects of straw (rooting material) and maize silage (roughage) provided under a roof in a concrete-floored outdoor run on the behaviour of organic fattening pigs raised in large groups. In one typical Danish commercial farm, we compared three adjacent, similarly sized pens. Each pen contained an indoor area and an outdoor run. Each outdoor run was divided by a 1 m-high concrete wall into an unroofed area and an area covered by a roof, where substrate could be allocated. One pen received no material under the roof (control), the second pen received straw, and the third pen received maize silage. The study took place from June 2021 to July 2022 and involved 8 batches of pigs. The population size per pen at arrival was (average ± standard deviation) 384 ± 22 pigs, weighing 37 ± 4.8 kg. Pigs were sent to slaughter when their liveweight was approximately 115 kg, approximately 3 months after insertion. Based on footage, the number of pigs present in each area of the outdoor run, and of these the number of pigs in each body posture (lying; sitting; upright) and the number of pigs displaying activity behaviours when standing (exploring the ground; other behaviours than ground exploration) were instantaneously sampled at 10 min intervals from 09:00 h to 16:00 h on days 1, 7, 21, 35, 49, and 63 relative to the batch insertion. More pigs were seen in the roofed area of the outdoor run when either straw or roughage were allocated. Additionally, provision of straw induced more resting in the roofed area whereas allocation of roughage stimulated more ground exploration in the roofed area compared to control pens. Secondarily, pig's activity and outdoor run use were influenced by temporal effects (i.e., experimental day) and weather variations. Thirdly, a pilot study suggested that pigs compete for access to an enriched roofed area. Our study demonstrated the possibility of meeting the behavioural needs - and improving the welfare – of organics pigs housed indoors with access to outdoor run by providing roughage or bedding materials in a roofed area of the outdoor run.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105554"},"PeriodicalIF":1.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001604/pdfft?md5=e7c19e1fecaf53f52deff68d2eefc513&pid=1-s2.0-S1871141324001604-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Profitability, greenhouse gas emissions and feed-food competition of strategies to exploit compensatory growth in Uruguayan weanling-to-beef systems","authors":"J.M. Clariget ,&nbsp;A.K. Kelly ,&nbsp;G. Banchero ,&nbsp;K. Keogh ,&nbsp;D.A. Kenny ,&nbsp;P. Crosson","doi":"10.1016/j.livsci.2024.105553","DOIUrl":"10.1016/j.livsci.2024.105553","url":null,"abstract":"<div><p>This study evaluates nutritional and management strategies aimed at exploiting compensatory growth (CG) in weanling-to-beef systems in Uruguay. The evaluation encompassed productivity, economic viability, and environmental impact. The Grange Beef System Model, augmented with Uruguayan national technical coefficients, was used. Four weanling-to-beef systems were modeled: 1) forage only with no CG (FNC), 2) forage only with management improvements to exploit CG (forage with CG; FWC), 3) forage with concentrate supplementation during two winter feeding periods (forage with supplementation; FWS), and 4) forage with supplementation during the first winter followed by feedlot finishing (forage with feedlot; FWF). The systems purchased spring-born Angus calves at 8 months of age and 180 kg live weight (LW) and finished with a slaughter weight of 550 kg. FWS system was used as reference with the performance parameters obtained during 5 years of systems experimentation. FNC used the performance parameters of FWS but during winter periods, LW gain was lower due to the absence of concentrate supplementation. FWC used the previous FNC performance parameters, but increased LW gain after the first and second winter restriction period due to improved grazing management practices thereby exploiting CG. FWF is based on the FWS system but instead of moderate supplementation during the second winter (concentrate: 3.0 kg/d/head), steers are feedlot finished (concentrate: 9.5 kg/d/head) exploiting CG due to previous summer-autumn restriction period. FNC and FWC increased age at slaughter, reducing net beef production by 21 and 11 % relative to FWS, respectively. In contrast, FWF reduced age at slaughter, increasing beef production by 93 % compared to FWS. FWS and FNC had similar profitability expressed in net margin; however, FWC and FWF increased net margin by 33 and 107 % compared to the FWS, respectively. FNC and FWC increased greenhouse gas (GHG) emissions intensity per beef produced by 17 and 3 % relative to FWS, respectively; meanwhile, FWF reduced GHG intensity by 10 % relative to FWS. Due to the inclusion of concentrates in the diet for FWS and FWF systems, the only net producers of human edible energy and protein were the forage-only systems (FNC and FWC). In summary, strategically harnessing CG in both pasture and feedlot finishing stages within a weanling-to-beef system in Uruguay successfully increased profitability. Feedlot finishing reduced GHG emissions per beef produced. However, the forage-only farm systems emerged as the only net producers of human-edible energy and protein.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105553"},"PeriodicalIF":1.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001598/pdfft?md5=6dd28a03b027172d5d225ff50bee7038&pid=1-s2.0-S1871141324001598-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amino acid supplementation and substitution of soybean meal in crude protein- and phosphorus-reduced diets for grower-finisher pigs: Effects on performance and modelled environmental impact","authors":"Reinhard Puntigam ,&nbsp;Mario Müller ,&nbsp;Manfred Weber ,&nbsp;Stefan Josef Hörtenhuber","doi":"10.1016/j.livsci.2024.105556","DOIUrl":"10.1016/j.livsci.2024.105556","url":null,"abstract":"<div><p>Pigs’ N and P excretions are partially lost as NH₃ or phosphate, resulting in potential environmental pollution and health risk for humans and animals. A study was conducted to investigate if supplementation of microbial phytase and free amino acids (AA) allows to decrease monocalcium phosphate (MCP) and solvent extracted soybean meal (SBM) in N- and P-reduced diets, and if these feeding strategies decrease environmental impacts while maintaining growth performance and meat quality traits. The impacts on greenhouse gas emissions (global warming, GW) and on acidifying emissions were modelled. Therefore, a total of 192 mixed-sexed pigs (body weight, BW: 32.6 ± 0.3 kg) were randomly allocated to 4 dietary treatments (4 pens per treatment and 12 pigs per pen, 48 pigs per treatment). Three-phase feed, supplemented with individual AA to maintain appropriate digestible AA to Lys ratios, were fed. The control treatment (CON) was formulated to contain 185 to 150 g kg^-1 CP (as-fed). In the ‘low reduction’ treatment (LRT) and the ‘high reduction’ treatment (HRT), SBM and thus CP contents were reduced (LRT: 185 to 123 g kg^-1; HRT: 161 to 123 g kg^-1; as-fed). In the ‘alternative protein’ treatment (APT), SBM was completely replaced with rapeseed meal and faba beans to achieve CP contents of 169 to 123 g kg^-1_, close to HRT. Monocalcium phosphate was not supplemented in all treatments after the starter period (60 kg BW). Average daily gain (ADG) and gain to feed-ratio (G:F) did not differ between CON and other treatments during the overall grower-finisher period. Pigs of HRT and APT showed less lean compared to pigs of CON, being correspondent with the reduced loin muscle of those animals (<em>P</em> &lt; 0.05). The meat quality traits did not differ between treatments although SBM per pig was markedly reduced or totally replaced (16, 13, 6.5, and 0 kg SBM per pig in CON, LRT, HRT, and APT, respectively). Nitrogen excretion was reduced (<em>P</em> &lt; 0.05) by 13, 20, and 12% in LRT, HRT, and APT, respectively, compared to pigs fed the CON diet. Phosphorus excretion was reduced by 23, 25, and 5% in LRT, HRT, and APT, respectively, compared to CON. Consequently, the lower N intake reduced acidification and GW impacts by up to 14% and 7%, respectively. Results indicate that CP- and P-reduced diets for grower-finisher pigs are effective in lowering N and P releases into the environment, while growth performance and meat quality traits are maintained.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105556"},"PeriodicalIF":1.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001628/pdfft?md5=2ef575e6c274d927bb88d58ab7dc0f57&pid=1-s2.0-S1871141324001628-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure to natural stray currents of low voltage affects the behaviour and some stress biomarkers of weaned piglets","authors":"Théo Nicolazo ,&nbsp;Elodie Merlot ,&nbsp;Charlotte Teixeira Costa ,&nbsp;Caroline Clouard ,&nbsp;Arnaud Lebret ,&nbsp;Céline Chevance ,&nbsp;Valérie Normand ,&nbsp;Justine Jeusselin ,&nbsp;Gwenaël Boulbria","doi":"10.1016/j.livsci.2024.105555","DOIUrl":"10.1016/j.livsci.2024.105555","url":null,"abstract":"<div><p>With the modernisation of pig breeding facilities, pigs may be exposed to both on-farm and off-farm sources of stray voltages. Data from ruminant species suggest that exposition to stray voltages may be a source of stress and impair animal welfare, but data are scarce for pigs. The aim of this study was to evaluate the impact of stray currents of voltages under 0.5 Volts in pig housing on piglet behaviours and some biomarkers after weaning. Two replicates of 820 piglets were reared in a farm naturally exposed to stray voltage for seven weeks. The difference in electrical potential between the floor and each drinker and feeder was measured every two weeks. Piglets exposed to high-voltage drinkers (HVD &gt; 125 mV) spent more time orally manipulating pen mates (<em>P</em> = 0.0031). They also spent more time lying inactive with open eyes (<em>P =</em> 0.0027) and less time nosing pen mates (<em>P =</em> 0.043), but these effects were influenced by the voltage in feeders (<em>P =</em> 0.0021 and <em>P =</em> 0.024, respectively). Piglets exposed to high-voltage feeders (HVF &gt; 50 mV) spent less time lying with their eyes closed (<em>P</em> = 0.024) and more time aggressing pen mates (<em>P</em> = 0.0081). Fifty days after entering the farm, blood hydroperoxide concentration was higher in piglets exposed to HVD (<em>P</em> = 0.039). The increase in socio-negative behaviours and oxidative stress in pigs exposed to stray voltages in pig housing suggested that stray voltages might have moderate detrimental consequences for piglets in post-weaning facilities.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105555"},"PeriodicalIF":1.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001616/pdfft?md5=1b29e743ee56e4e45523edb08e368d03&pid=1-s2.0-S1871141324001616-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142020704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of supplementing a feedlot diet with microalgae (Chlorella vulgaris) on the performance, carcass traits and meat quality of lambs","authors":"I.U. Gadzama ,&nbsp;L.C. Hoffman ,&nbsp;B.W.B. Holman ,&nbsp;A.V. Chaves ,&nbsp;S.J. Meale","doi":"10.1016/j.livsci.2024.105552","DOIUrl":"10.1016/j.livsci.2024.105552","url":null,"abstract":"<div><p>This study evaluated the effect of different levels of fresh microalgae (<em>Chlorella vulgaris</em>) in a feedlot diet on the performance, carcass traits, and meat quality of lambs. Forty-five, four-month-old wether lambs were randomly assigned to one of three dietary treatments: 1) CONTROL, without algae; 2) MEDIUM, with 0.5 % dry matter (DM) algae; or 3) HIGH, with 1 % DM algae added to a basal diet consisting of barley hay and commercial feedlot pellets in a 41:59 ratio. The lambs were fed for 98 days and then slaughtered. Microalgae supplementation did not affect (<em>P</em> ≥ 0.09) growth performance, wool quality, rumen fermentation parameters, carcass weight, dressing percentage, or subcutaneous fat thickness of the lambs. However, microalgae supplementation at 0.5 % DM increased (<em>P</em> ≤ 0.05) the concentration of alpha-linolenic acid (ALA; C18:3n-3), arachidic acid (C20:0), and total omega-3 long-chain (n-3 LC) fatty acids in the <em>longissimus lumborum et thoracis</em> (LTL) muscle of lambs, compared to the CONTROL. Intramuscular fat (%) was similar between the CONTROL and the MEDIUM group (av. 3.65 %), but was lower (<em>P</em> = 0.044) in the HIGH group (3.1 %). Therefore, our results indicate that adding 0.5 % DM microalgae to lamb diets can increase the levels of alpha-linolenic acid and total n-3 LC PUFA in fresh lamb meat without affecting lamb performance or carcass characteristics.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105552"},"PeriodicalIF":1.8,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871141324001586/pdfft?md5=76e5bab73867f63393248d71da19cfa4&pid=1-s2.0-S1871141324001586-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the effects of black pepper extract on the growth performance of grower pigs","authors":"Jian Ying Zhang ,&nbsp;Huan Wang ,&nbsp;Jing Hu ,&nbsp;In Ho Kim","doi":"10.1016/j.livsci.2024.105548","DOIUrl":"10.1016/j.livsci.2024.105548","url":null,"abstract":"<div><p>This study aimed to evaluate the effects of black pepper (BP) extract on growth performance, nutrient digestibility, serum total protein, blood urea nitrogen (BUN), creatinine, counts of <em>Lactobacillus</em> and <em>Escherichia coli (E. Coli)</em>, back fat thickness, lean meat percentage (LMP), and fecal gas emission in grower pigs. A total of 160 crossbred grower pigs [(Landrace × Yorkshire) × Duroc] with an average initial body weight (BW) of 25.31 ± 1.29 kg were used in a 42-day feeding trial. Pigs were randomly assigned to four experimental treatments. The basal diet was composed of soybeans and corn to meet or exceed the NRC (2012) recommendations. The dietary treatments included: basic diet, basic diet + 0.025 %, 0.05 %, and 0.1 % BP extract. There were eight replicates per treatment, each comprising five pigs (three gilts and two barrows). All data were subjected to statistical analysis using general linear model procedures (SAS 2001, SAS Institute Inc., Cary, NC, USA), with the pen serving as the experimental unit. The results indicated a linear improvement in BW and average daily gain of pigs during days 1–28, 28–42, and the overall period with increasing levels of BP extract in the diet. The apparent total tract digestibility (ATTD) of crude protein (CP) and lean meat percentage (LMP) increased linearly with BP treatment at the end of the experiment (<em>p</em> &lt; 0.05). In addition, total protein, BUN, and creatinine levels were not affected by the BP extract (<em>p</em> &gt; 0.05). Some fecal microbes, such as <em>Lactobacillus</em> and <em>E. coli</em>, did not change considerably when pigs were fed BP extract (<em>p</em> &gt; 0.05). No apparent response to faecal gas emission of NH₃, total mercaptans, or H₂S was observed in relation to the BP extract in the pig diet (<em>p</em> &lt; 0.05). Dietary supplementation with 0.1 % BP extract improved growth performance by increasing the ATTD of CP and improving LMP without adverse effects in grower pigs.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105548"},"PeriodicalIF":1.8,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-genome sequencing of Ganzi horse reveals the genetic diversity and provides unique insights into its plateau adaptation","authors":"Jiale Han,&nbsp;Meixuan Lu,&nbsp;Cong Li,&nbsp;Minhao Sun,&nbsp;Qiaoyan Hu,&nbsp;Yidan Li,&nbsp;Halima Jafari,&nbsp;Zhaofei Wang,&nbsp;Pengcheng Zhao,&nbsp;Ruihua Dang","doi":"10.1016/j.livsci.2024.105549","DOIUrl":"10.1016/j.livsci.2024.105549","url":null,"abstract":"<div><p>Ganzi horse is distributed in the Ganzi Tibetan Autonomous Prefecture. As we all know, this region on the southeast of the Tibetan Plateau is characterized by low oxygen levels, low atmospheric pressure, and intense ultraviolet light. The extreme environment causes the genomic variation of plateau animals for environmental adaptation. At present, the genetic diversity and the genetic basis of high-altitude adaptation of Ganzi horses remain unclear. Here, an extensive genetic analysis was conducted utilizing whole-genome sequencing data from 145 individual horses. The analysis of autosomal genetic diversity confirmed that Ganzi horses had experienced low intensity artificial selection and had high genetic diversity. Examination of mitochondrial DNA information from whole-genome sequencing data revealed multiple maternal origins for Ganzi horses. Further, four different selective scanning methods were used to identify positive selected genomic regions and genes associated with high-altitude adaptation. We identified genes associated with altitude adaptation at selection windows in Ganzi horses, such as <em>EPAS1, ABTB2, RHOQ</em>, and <em>TMEM247</em>. Notably, <em>EPAS1</em> and <em>OR52A1J</em> gene exhibited high select signal values, different nucleotide diversities, and haplotype patterns, and missense mutations in <em>EPAS1</em> (<em>A</em> &gt; <em>T</em>) and <em>OR52A1J</em> (C &gt; T) were found to be more frequent in high-altitude horses. Moreover, our research illuminated significant gene flow between Ganzi and Chaidamu horses, which may be related to the formation of Ganzi horses. In general, these findings not only enhance our understanding of this unique native breed but also further our understanding of Ganzi horse's high-altitude adaptation.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105549"},"PeriodicalIF":1.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-wide assessment of runs of homozygosity to estimate inbreeding in a closed Nellore herd","authors":"Angela Bittencourt ,&nbsp;Andréa Alves do Egito ,&nbsp;Paula Adas Pereira Suniga ,&nbsp;Gustavo Garcia Santiago ,&nbsp;Rafael Monteiro dos Santos ,&nbsp;Eduardo Penteado Cardoso ,&nbsp;Lucas Lima Verardo ,&nbsp;Marcos Vinicius Gualberto Barbosa da Silva ,&nbsp;Fabio Luiz Buranelo Toral","doi":"10.1016/j.livsci.2024.105547","DOIUrl":"10.1016/j.livsci.2024.105547","url":null,"abstract":"<div><p>The objective of this study was to compare the inbreeding coefficients estimated from pedigree data (F_PED), traditionally used for internal monitoring by herds and breeding programs, with genomic estimates through the genomic relationship matrix (F_GRM) and runs of homozygosity (F_ROH). Besides, we used the genotype data to obtain the linkage disequilibrium (LD), population effective size (Ne), runs of homozygosity (ROH) islands and functional analysis of the genes presented in ROH islands. Male calves and sires from a closed Nellore herd (Lemgruber line) were genotyped with the Z-chip v2 (Neogen, Lincoln, Nebraska, USA) that contains approximately 30 thousand SNP markers. After quality control, 1088 animals and 21,351 SNPs remained for analysis. Runs of homozygosity (ROH) segments were identified in all analyzed animals, with an average number of 57.93 and average length of 2.95 Mb. We observed a higher occurrence of ROH up to 9 Mb, suggesting a proper mating scheme, which corroborate with LD and Ne analysis results. Estimates of F_PED, F_GRM and F_ROH ranged from 0 to 0.2856, from 0.0705 to 0.3686 and from 0.0229 to 0.2762, respectively. Low to moderate correlations were observed between F_PED and F_GRM (0.17, <em>P</em> &lt; 0.001); F_PED and F_ROH (0.20, <em>P</em> &lt; 0.001) and F_GRM and F_ROH (0.92, <em>P</em> &lt; 0.001). Nevertheless, considering our results we were successful in use runs of homozygosity for estimating autozygosity in a closed Nellore herd. Besides, from ROH islands, we were able to identify a candidate gene (HTR1A) for docility in this Nellore herd.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105547"},"PeriodicalIF":1.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partitioning of energy intake in broiler breeders from 27 to 63 weeks old","authors":"Guilherme Ferreira da Silva Teofilo ,&nbsp;Freddy Alexander Horna Morillo ,&nbsp;Damilola Uthman Kareem ,&nbsp;Rony Riveros Lizana ,&nbsp;Lucas Pimentel Bonagurio ,&nbsp;Rosiane de Souza Camargos ,&nbsp;Jacob Van Milgen ,&nbsp;Marcos Macari ,&nbsp;Nilva Kazue Sakomura","doi":"10.1016/j.livsci.2024.105535","DOIUrl":"10.1016/j.livsci.2024.105535","url":null,"abstract":"<div><p>Describing the energy partition during the production phase of broiler breeders helps to define the energy requirements of breeders. This study aimed to determine the energy intake partition for maintenance, tissue growth, and egg production in broiler breeders during the laying phase. An energy and nitrogen balance study was carried out in a respirometry chambers with fifty Cobb 500 broiler breeders from 27 to 63 weeks old. Every four weeks, 5 birds were individually housed in a respirometry chamber and fed according to the guidelines. Feed intake (<strong>FI</strong>), excreta, and egg output were recorded daily. O₂ consumption (<strong>VO₂</strong>) and CO₂ production (<strong>VCO₂</strong>) were measured under feeding and fasting conditions to calculate total and fasting heat production (<strong>THP</strong> and <strong>FHP</strong>, respectively). The collected data were used to calculate the retained energy (<strong>RE</strong>) in the egg and body as protein or fat by using energy balance calculations. Linear regressions were used to fit the collected data as a function of age. The measured apparent metabolizable energy corrected for zero-nitrogen retention <strong>(AMEn</strong>, kJ/kg feed) was higher than formulated. The FI and apparent metabolizable energy intake (<strong>AMEi</strong>) showed the highest values at 31 and 35 weeks (<em>P</em> &gt; 0.05). Linear regression was not significant (<em>P</em> &gt; 0.05) for FHP, THP, heat increment (<strong>HI</strong>), egg mass, and RE in the egg as fat and as protein, suggesting that these parameters remained constant as the bird aged. The RE in the body as protein increased (<em>P</em> &lt; 0.005), while the RE in the body as fat decreased (<em>P</em> &lt; 0.0001) as the birds aged. Variation in the AMEi influenced RE in the body (<em>P</em> &lt; 0.05) but not in the egg (<em>P</em> = 0.109). It can be concluded that net energy for maintenance does not change during the laying phase and represents an expenditure of 267.1 kJ/kg^0.75 per day in broiler breeders under a feed-controlled program. As expected, energy is primarily used for maintenance and egg production in the net energy system, with excess energy stored preferentially as fat rather than protein.</p></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"288 ","pages":"Article 105535"},"PeriodicalIF":1.8,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142020703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}