Livestock Science最新文献

{"title":"Genetic parameters for litter and carcass traits in Landrace and Yorkshire pigs","authors":"Iasmin Marques Rocha ,&nbsp;Giovanna Maria dos Santos Câmara ,&nbsp;Maria Victória Henrique Genuíno ,&nbsp;Ayrton Fernandes de Oliveira Bessa ,&nbsp;Roney Teixeira ,&nbsp;Luis Artur Loyola Chardulo ,&nbsp;Rogério Abdallah Curi ,&nbsp;Welder Angelo Baldassini ,&nbsp;Guilherme Luis Pereira ,&nbsp;Daniela do Amaral Grossi ,&nbsp;Marcos Eli Buzanskas","doi":"10.1016/j.livsci.2025.105843","DOIUrl":"10.1016/j.livsci.2025.105843","url":null,"abstract":"<div><div>Swine production has focused on improving litter size and carcass traits to enhance productivity. Genetic progress in traits such as the number of piglets born alive (NBA), birth weight (BW), number of piglets weaned (NPW), total teat number (TN), number of days to reach 100 kg (AGE100), backfat thickness (BF), and loin depth (LD) is of great importance for breeding efficiency. The present study aimed to estimate genetic parameters, including heritability and genetic correlations, for the mentioned traits in Landrace and Yorkshire pigs. Genetic parameters were estimated using the restricted maximum likelihood method, considering an animal model. Heritability estimates ranged from 0.06 (NPW) to 0.41 (BW) in Landrace and 0.04 (NPW) to 0.40 (BW) in Yorkshire. Maternal heritability and permanent environmental effects were low, with values between 0.02 and 0.05. The maternal permanent environmental variance ranged between 0.03 and 0.09. Repeatability estimates for all traits ranged from 0.10 (NPW) to 0.49 (BW). All the traits studied showed sufficient additive genetic variability, enabling effective selection in Landrace and Yorkshire pigs. Greater relative responses are expected for BF, BW, NBA, LD, and TN. Selection for BW may yield favorable correlated responses with NPW, TN, and AGE100, while direct selection for TN may enhance sow reproductive performance. Genetic correlations between BF and LD indicated that both traits can be improved simultaneously without unfavorable effects. Although the correlation between NBA and BW was not high, caution is warranted regarding the increase in litter size due to potential negative consequences, such as reduced birth weight and higher piglet mortality. Despite previous investigations on these traits, this study provides updated and robust estimates from a large, consistent, and environmentally controlled population, representing a valuable case study for commercial swine breeding programs.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105843"},"PeriodicalIF":1.9,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418112","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":"A rapid laboratory method for estimating the standardised precaecal digestible amino acids in pig feeds","authors":"Valérie Schumacher ,&nbsp;Markus Rodehutscord ,&nbsp;Karl-Heinz Südekum ,&nbsp;Saskia Kehraus","doi":"10.1016/j.livsci.2025.105841","DOIUrl":"10.1016/j.livsci.2025.105841","url":null,"abstract":"<div><div>Amino acids (AA) are essential nutrients for diverse processes in the pig’s body. The utilisation of AA depends on their digestibility and absorption. Therefore, methods to determine reliably the AA supply to pigs to sustain performance and animal health are critical for precise feed evaluation. The evaluation of AA supply has so far been based on <em>in vivo</em> determination of standardised precaecal digestible (pcd) AA (pcdAA) and <em>in vitro</em> estimates of pcdAA applying time-consuming and complex laboratory methods. The objective of this study was to develop and establish a rapid laboratory method for estimating pcdAA based on the determination of AA insoluble in neutral-detergent (ND) or acid-detergent (AD) (NDIAA, ADIAA). The laboratory method used the same procedure which was previously applied to estimate standardised pcd crude protein (pcdCP). The hypothesis was that the method was similarly suitable to estimate pcdAA. A sample pool of 74 feed ingredients (cereal grains, differently heat-treated legume grains) was available on which <em>in vivo</em> pcdAA were determined in cannulated pigs. Amino acids in feed ingredients and in ND or AD residues of feed ingredients were determined by an HPLC method. The concentrations (g/kg dry matter) of ND- and AD-soluble AA (NDSAA, ADSAA) were calculated by difference to total AA in feed. For the estimation of the concentrations of <em>in vivo</em> pcdAA for total AA and the entire dataset (<em>n</em> = 74), a linear relationship was established between the concentrations of NDSAA or ADSAA and the <em>in vivo</em> pcdAA: y = 0.823 (standard error [SE] 0.018) x + 10.52 (SE 4.420), where y represents the <em>in vivo</em> pcdAA (g/kg dry matter) and x represents the NDSAA (cereal grains) or ADSAA (protein feeds) value (g/kg dry matter). The coefficient of determination (R²) of this equation was 0.968 and ranged from 0.895 to 0.984 for the 17 individual AA. This study shows that <em>in vivo</em> pcdAA values can be estimated following the same standardised and rapid laboratory procedure previously established for pcdCP, based on chemical analyses, namely determination of NDIAA and ADIAA, from which NDSAA and ADSAA values are calculated.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105841"},"PeriodicalIF":1.9,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466250","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":"Frequency of the beta-carotene oxygenase 2 (BCO2) allele associated with the yellow fat phenotype in rabbits: insights into the spread of a genetic alteration in a wide variety of breeds and populations","authors":"Valeria Taurisano ,&nbsp;Anisa Ribani ,&nbsp;Samuele Bovo ,&nbsp;Giuseppina Schiavo ,&nbsp;Francesca Bertolini ,&nbsp;Michele Schiavitto ,&nbsp;Luca Fontanesi","doi":"10.1016/j.livsci.2025.105842","DOIUrl":"10.1016/j.livsci.2025.105842","url":null,"abstract":"<div><div>In various animal species, the accumulation of carotenoids that are not completely metabolized leads to yellow fat pigmentation. In rabbits, the yellow-fat phenotype was described by classic genetic studies at the beginning of the last century to be determined by a simple Mendelian recessive allele at the <em>Yellow</em> locus, in linkage with the <em>Albino</em> coat colour locus. More recent studies reported that a deletion of three nucleotides at codon 248 of the beta-carotene oxygenase 2 (<em>BCO2</em>) gene (delAAT) is the causative mutation for the yellow-fat defect when in a homozygous state. In this study, we genotyped the <em>BCO2</em> polymorphic site in 1041 rabbits from 41 breeds and populations, including albino rabbit breeds. Considering the overall genotyped population, the frequency of the delAAT allele was 11.96%. Homozygous delAAT/delAAT rabbits had a frequency of 3.55%, while the heterozygous rabbits had a frequency of 16.81%. In 12 out of 41 breeds/populations, all rabbits analysed were homozygous for the wild-type allele, while in 29 the mutated allele segregates. Only one breed, Lynx (with a pale silver-blue coat colour and yellow-red shades), was fixed for the delAAT allele, suggesting its potential functional role in determining the yellow-red secondary tint that characterises this breed. Comparing the molecular genetic results with the genetic information reported in earlier literature, the frequency of the mutated allele decreased over the last 80 years, probably due to culling of the carriers for the negative effect on carcass quality, due to the preference of consumers for white fat in rabbit meat.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105842"},"PeriodicalIF":1.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364636","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":"Review: Strategies to stimulate piglet creep feed intake before weaning","authors":"Malene Hald ,&nbsp;Thomas S. Bruun ,&nbsp;Trine F. Pedersen ,&nbsp;Mette S. Hedemann","doi":"10.1016/j.livsci.2025.105840","DOIUrl":"10.1016/j.livsci.2025.105840","url":null,"abstract":"<div><div>Stimulating creep feed intake in piglets is increasingly important due to larger litter sizes, which raise piglet requirements to levels above the sow milk production. Although intake is typically low during the initial weeks, piglets show exploratory behavior (nosing, rooting, and chewing) from the first week of life. Supporting this behavior in conventional farrowing environments can promote early feed engagement. This review highlights strategies to enhance creep feed intake, including housing and creep feeder design, feeding practices, feed characteristics, and management. Creep feeder design and sow confinement (crated vs. loose) affect piglet interaction with feed. Introducing solid feed between 5 and 10 days after farrowing is recommended. The physical form of creep feed (e.g., meal, pellets, crumbles, thermally processed, or liquid) plays a key role. Pellet diameter is especially important; larger pellets (≥ 8 mm) stimulate feeding behavior. Sensory properties (taste, smell, texture) are less critical in attracting piglets. While dietary complexity can influence intake, high-complexity diets do not always outperform low complexity diets, even though these may contain less ingredients and less refined ingredients. Flavor additives, either in the sow’s diet or the creep feed, may improve palatability and familiarity. Increasing the weaning age is the most efficient tool to increase creep feed intake and reduce the proportion of non-eaters at weaning. In conclusion, a multifactorial approach integrating these elements may be most effective in optimizing early feed consumption and adapting to solid feed before weaning.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105840"},"PeriodicalIF":1.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363932","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":"Genetic parameters and genomic predictions for economically important traits in Montana® composite cattle using different models","authors":"Flávia Cristina Bis ,&nbsp;Eduarda da Silva Oliveira ,&nbsp;Caroline Assis Almeida ,&nbsp;Elisângela Chicaroni de Mattos Oliveira ,&nbsp;Letícia Pereira ,&nbsp;Rafael Espigolan ,&nbsp;Joanir Pereira Eler ,&nbsp;Luís Telo Da Gama ,&nbsp;Rafael Nuñez Dominguez ,&nbsp;José Bento Sterman Ferraz ,&nbsp;Fernando Baldi","doi":"10.1016/j.livsci.2025.105839","DOIUrl":"10.1016/j.livsci.2025.105839","url":null,"abstract":"<div><div>This study assessed the impact of breed effects, heterosis, and recombination on genomic predictions for growth, reproduction, and body composition traits in Montana® cattle. The database included 124,547 records for Birth Weight (BW), 111,103 for Weaning Weight (WW), 87,740 for Weight at 12 months (W12), 49,249 for Post-weaning Weight Gain (WG), 87,740 for Scrotal Circumference (SC), and 44,873 for Muscularity (MUSC), with 3911 genotyped animals from the Montana® composite program. Models M1 to M5 included fixed effects of contemporary group, embryo transfer, and cow age at calving (linear and quadratic). The effects of direct and maternal breed composition, heterozygosity, and recombination varied across models. From model M2 onward, covariates for biological type, heterosis (direct, maternal, specific), and recombination (direct, maternal, specific) were added. All genomic analyses used the ssGBLUP method, and the LR (Linear Regression) validation method was used to assess predictive ability and model effect influence. Heritability estimates ranged from 0.19 to 0.22 for WW, 0.15 to 0.20 for WG, 0.36 to 0.37 for BW, 0.23 to 0.29 for W12, 0.28 to 0.29 for SC, and 0.17 to 0.19 for MUSC. The most parameterized models showed the best fit by AIC, with M5 best for WW, W12, WG, and SC; M4 for BW; and M3 for MUSC. Model M1 showed the best prediction ability for WW and W12, with the highest accuracies (0.407 and 0.456), best dispersions (1.01 and 0.897), and lowest biases (0.098 and 0.068), respectively. For WG, M1 had the highest accuracy (0.452), M5 the best dispersion (0.940), and M4 the lowest bias (0.028). For BW, M5 showed the highest accuracy (0.452), M4 the best dispersion (1.001), and M3 the lowest bias (-0.006). For SC, M1 had the highest accuracy (0.501), M3 the best dispersion (1.004), and M4 the lowest bias (0.092). For MUSC, M4 had the highest accuracy (0.415) and lowest bias (0.057), while M2 showed the best dispersion (0.979). More parameterized models provided a better fit for variance component estimation. In general, genomic predictions with M1 displayed the highest accuracies for WW, W12, WG, and SC, and lower bias for most traits.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105839"},"PeriodicalIF":1.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364637","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":"Effect of pre-weaning nutrition on the epigenetic and transcriptomic regulation of mammary gland development in Holstein heifers","authors":"Ewelina Semik-Gurgul ,&nbsp;Klaudia Pawlina-Tyszko ,&nbsp;Artur Gurgul ,&nbsp;Tomasz Szmatoła ,&nbsp;Justyna Rybińska ,&nbsp;Iwona Furgał-Dzierżuk ,&nbsp;Barbara Niwińska","doi":"10.1016/j.livsci.2025.105838","DOIUrl":"10.1016/j.livsci.2025.105838","url":null,"abstract":"<div><div>Dairy calves require a balanced diet that ensures adequate nutrient intake to support optimal growth and physiological development, which may subsequently influence future lactational performance and reproductive capacity through favourable epigenetic modifications in body tissues. This study aimed to investigate the impact of pre-weaning nutritional strategies on the epigenome and transcriptome of the mammary gland tissues in Holstein heifers. Twelve Holstein-Friesian heifer calves were included in the experiment. During their first two weeks of life, all calves received a milk replacer (MR) that met their nutritional requirements, along with unlimited access to concentrate feed and water. At 14 ± 1 days of age, the calves were randomly assigned to one of two feeding treatments. The applied diets involved restricted milk replacer intake (R, <em>n</em> = 6) and ad libitum milk replacer intake (AL, <em>n</em> = 6). Feeding treatments lasted for 48 days, after which all calves were euthanised at 62 ± 1 days of age. Mammary parenchyma (PAR) and mammary fat pad (MFP) tissues were collected and analysed using RRBS, miRNA-seq, and RNA-seq approaches. When comparing two diets, 268 differentially methylated sites (DMSs) were identified in the PAR, and 288 DMSs were found in MFP tissue. The obtained data allowed identification of four differentially expressed miRNAs (DE miRNAs) in PAR and 35 DE miRNAs in MPF tissue. Furthermore, transcriptomic analysis revealed that mammary fat pad tissue reacted to varying diets with a higher number of differentially expressed genes, indicating that parenchyma tissue is less responsive to nutritional changes. Based on integrative omics analysis, specific genes were identified in MFP tissue, whose expression levels were correlated with the level of CpG methylation and miRNA expression, revealing enriched biological processes. However, several important limitations should be considered when interpreting these results, including the relatively small sample size and the absence of long-term follow-up. These findings suggest that pre-weaning feeding strategies have a significant influence on the epigenetic regulation of gene expression, potentially determining the future lactation potential of dairy heifers.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105838"},"PeriodicalIF":1.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321710","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":"A diet containing Cyberlindnera jadinii yeast as a protein source demonstrates comparable benefits to a formic acid and probiotic supplemented diet in post-weaning piglets","authors":"Özgün C Onarman Umu ,&nbsp;Henning Sørum ,&nbsp;Anne Stine Ekker ,&nbsp;Peng Lei ,&nbsp;Purushothaman Kathiresan ,&nbsp;Charles McLean Press ,&nbsp;Kari Ljøkjel ,&nbsp;Liv Torunn Mydland ,&nbsp;Nils Petter Kjos ,&nbsp;Margareth Øverland","doi":"10.1016/j.livsci.2025.105835","DOIUrl":"10.1016/j.livsci.2025.105835","url":null,"abstract":"<div><div>The increasing demand for sustainable protein sources in livestock production necessitates the evaluation of novel feed ingredients that can reduce environmental impact while maintaining animal health and performance. The effects of replacing soybean meal with <em>Cyberlindnera jadinii</em>, a locally produced microbial yeast protein, in the diet of post-weaning piglets under commercial production conditions were analyzed. A total of 840 piglets were enrolled in a field experiment conducted over 3 consecutive production periods. Piglets were allocated to 2 dietary treatments: a control diet containing soybean meal, formic acid products and a probiotic, and an experimental diet where <em>C. jadinii</em> yeast replaced 45% of the dietary protein. Growth performance, fecal consistency, and gut microbiota composition were evaluated over a 4 wk post-weaning period. Piglets fed the yeast-based diet exhibited an overall lower average daily gain (ADG; <em>P</em> &lt; 0.01) and average daily feed intake (ADFI; <em>P</em> &lt; 0.01) compared to those on the control diet, while feed conversion ratio (FCR) remained similar between groups. No differences in fecal consistency or clinical signs of diarrhea were observed, indicating maintained gut health despite reduced feed intake. Microbiota profiling revealed dietary effects on microbial diversity and composition in both the ileum and colon. Notably, the yeast-fed piglets showed greater relative abundances of <em>Lactobacillus johnsonii, Streptococcus gallolyticus</em>, and members of the Prevotellaceae family, while the control-fed piglets had greater abundances of <em>Lactobacillus amylovorus</em> and <em>Blautia hansenii</em>. These findings indicate that <em>C. jadinii</em> yeast can partially replace soybean meal and formic acid in weaner pig diets without compromising health status, although some reduction in growth performance was observed. The altered gut microbiota, including enrichment of beneficial taxa such as <em>L. johnsonii</em>, suggests functional modulation of gut health, supporting the potential of yeast-based proteins as a sustainable feed strategy in pig production systems.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105835"},"PeriodicalIF":1.9,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321715","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":"Effect of heat stress and feed restriction on performance, carcass traits, and meat quality of growing rabbits","authors":"Emanuele Pontalti ,&nbsp;Marco Cullere ,&nbsp;Zsolt Szendrő ,&nbsp;Zsolt Matics ,&nbsp;Zsolt Gerencsér ,&nbsp;Bianca Palumbo ,&nbsp;Antonella Dalle Zotte","doi":"10.1016/j.livsci.2025.105836","DOIUrl":"10.1016/j.livsci.2025.105836","url":null,"abstract":"<div><div>The effects of heat stress and feed restriction were evaluated on a total of 180 weaned rabbits divided into three experimental groups (60 animals/group): 2 groups were fed <em>ad libitum</em> and reared under different temperatures (20 °C – 20AD and 30 °C – 30AD), while a third group was housed under controlled temperature (20 °C) but pair-fed to 30AD rabbits, thus feed restricted (20FR). During the trial, both 30AD and 20FR groups exhibited reduced growth performance, including body weight and daily weight gain (both, <em>P</em> &lt; 0.001), although feed conversion ratio improved (<em>P</em> = 0.016). The reference carcasses of 20FR and 30AD rabbits were lighter and leaner (both, <em>P</em> &lt; 0.001) than that of 20AD rabbits, while the slaughter yield decreased only in 20FR rabbits (<em>P</em> = 0.001). Regarding meat physical traits, 20FR rabbits exhibited the highest pHu (<em>P</em> &lt; 0.001) and the lowest total losses (<em>P</em> &lt; 0.001), whereas the meat-to-bone ratio decreased in both 20FR and 30AD groups (<em>P</em> = 0.007). As for meat proximate composition, protein and lipid contents were lower (<em>P</em> = 0.008 and <em>P</em> = 0.0002, respectively) in 20FR and 30AD rabbits, while water content was greater (<em>P</em> &lt; 0.001) compared to 20AD rabbits. At the lipid level, higher TBARS (<em>P</em> = 0.001) were found in both 20FR and 30AD groups. The 20FR and 30AD groups showed some differences in their carcass and meat quality traits, however the majority of changes induced by chronic heat stress were mostly attributed to the reduced feed intake.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105836"},"PeriodicalIF":1.9,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321711","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":"Refining Irish breeding goals for sustainable suckler systems through the incorporation of an enteric methane emissions trait","authors":"Clodagh V. Ryan ,&nbsp;Deirdre C. Purfield ,&nbsp;David Kenny ,&nbsp;Paul Crosson ,&nbsp;Ross D. Evans","doi":"10.1016/j.livsci.2025.105837","DOIUrl":"10.1016/j.livsci.2025.105837","url":null,"abstract":"<div><div>Genetic selection presents a long-term opportunity to reduce enteric methane emissions in beef cattle. This study evaluated the effect of incorporating an enteric methane production trait into the Irish Terminal Index, an index that is typical of global terminal-type indexes and quantified its impact on methane output and other economically important traits. At present, the Irish Terminal Index incorporates a Carbon sub-index based on life cycle assessment in an effort to reduce farm carbon emissions. Selection index scenarios were modelled to reflect an index with no environmental consideration, the current status quo, the inclusion of a direct enteric methane trait and finally the impact of changes in carbon pricing. Genetic parameters were derived from a national multi-breed dataset of 1508 beef animals with enteric methane phenotypes. Selection based on the current index which includes a lifecycle carbon weighting, increased daily enteric methane emissions by up to 2.14 g/day, while the inclusion of a direct enteric methane trait reversed the response, with predicted reductions of 0.22g/day and 4.20 g/day depending on carbon price. Associated changes included a 13.81 kg increase in carcass weight response and a 0.33 kg reduction in feed intake per animal under the highest environmental weighting (Carbon valued at €160/tonne and a direct enteric methane trait). Scaled to the national herd, this would equate to an annual reduction of approximately 27,400 tonnes of carbon dioxide equivalent and an opportunity cost of 1311 tonnes of carcass output. Selection direction remained favourable across all production traits, with minimal impact on calving, docility, and conformation traits. These results demonstrate that enteric methane can be incorporated into the national breeding goal with measurable reductions in emissions and limited trade-offs in economically relevant performance traits.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105837"},"PeriodicalIF":1.9,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364635","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":"Calf presence in the cow herd: Associations with growth, health, and herd horn status in a cow-calf contact system","authors":"Romane Gillet ,&nbsp;Marie Schneider ,&nbsp;Kerstin Barth","doi":"10.1016/j.livsci.2025.105834","DOIUrl":"10.1016/j.livsci.2025.105834","url":null,"abstract":"<div><div>Prolonged cow-calf contact in dairy farming is receiving considerable attention. However, research on systems that allow calves to access the whole dairy herd has been limited. This study investigated the time that German Holstein calves spent daily within the dairy herd of their dams, its association with calf growth and health, and the effect of herd (horned vs. polled). The calves with whole-day contact (WDC, <em>n</em>= 23) could enter the herd at any time during the day, except during milking; the calves with daytime contact (DTC, <em>n</em>= 26) had only access between morning and evening milking. Calves with no herd contact (NOC, <em>n</em>= 42) served as a control. Calves were weighed weekly and their health status was assessed. Between the 2nd and 11th weeks of life, the time spent in the cow herd decreased in WDC calves (h d^-1, horned WDC: - 10.9, polled WDC: - 3.7, <em>P</em>&lt; 0.001), but did not differ in DTC calves (<em>P</em>&gt; 0.1). More time in the herd was associated with higher growth rates (<em>P</em>= 0.003). However, no effect of the herd was observed on calf growth or health. WDC calves had the highest growth rate compared to DTC and NOC (g d^-1, 991 ± 36, 718 ± 35, 869 ± 28, respectively, <em>P</em>&lt; 0.05). Unrestricted access to the cow herd resulted in individual variation in the time calves spent within the herd, with no observed effects on growth or health.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"302 ","pages":"Article 105834"},"PeriodicalIF":1.9,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321712","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}