Small Ruminant Research最新文献

{"title":"Development and validation of 10 K liquid chip for Inner Mongolia cashmere goat","authors":"Qi Xu ,&nbsp;Haijiao Xi ,&nbsp;Dongmei Shen ,&nbsp;Tao Zhang ,&nbsp;Jinquan Li ,&nbsp;Rui Su ,&nbsp;Qi Lv ,&nbsp;Yanjun Zhang ,&nbsp;Ruijun Wang ,&nbsp;Na Wang ,&nbsp;Baichuan Liu ,&nbsp;Dong He ,&nbsp;Zhiying Wang","doi":"10.1016/j.smallrumres.2025.107598","DOIUrl":"10.1016/j.smallrumres.2025.107598","url":null,"abstract":"<div><div>The aim of this study was to design and develop a 10 K low-density liquid chip for cashmere goats using targeted capture sequencing technology. The functional sites of this chip combine SNPs significantly related to early growth traits, cashmere traits, and horn traits of Inner Mongolia cashmere goats, as well as some sites from the 70 K chip. The background sites were determined based on the principles of uniformity of sites on chromosomes and maximizing minor allele frequency. Finally, a low-density liquid chip containing 10,000 SNP sites was synthesized, comprising 997 functional sites and 9003 background sites, all of which are evenly distributed across each chromosome.The chip was validated using 37 DNA samples from Inner Mongolia cashmere goats. The results showed that the average detection rate of sites in the test samples was 99.63 %. All SNP sites were annotated, with 64 % located in intergenic regions. The development and validation of the 10 K liquid chip for cashmere goats demonstrate its potential for application in molecular breeding of cashmere goats, which is expected to further promote the industrial development of this species.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107598"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921712","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 treating Searsia lancea with polyethylene glycol on performance of Boer goats fed Cenchrus ciliaris based diet","authors":"Onke Hawu,&nbsp;Khuliso E. Ravhuhali,&nbsp;Hilda K. Mokoboki,&nbsp;Cornelia K. Lebopa","doi":"10.1016/j.smallrumres.2025.107582","DOIUrl":"10.1016/j.smallrumres.2025.107582","url":null,"abstract":"<div><div>This study examined the effect of treating <em>Searsia lancea</em> with incremental levels of polyethylene glycol (PEG) on growth performance, blood parameters, and apparent nutrient digestibility of Boer goats fed grass hay. Twenty-five (25) male Boer goats with an average weight (27 ± 2 kg) were allocated to dietary treatments offered in a complete randomized design (CRD). Dietary treatments were <em>Cenchrus ciliaris</em> at 60 % grass mixed with 40 % PEG-treated <em>S. lancea</em> at 0, 5, 10, 15, and 20 g/kg DM leaves. The dry matter (DM) intake exhibited positive linear and quadratic effects (P = 0.002 and P = 0.021). There was a positive quadratic effect (P &lt; 0.05) on the intake of ash, CP, NDF, and ADF. The average daily gain (ADG) exhibited positive linear responses (P = 0.039) in response to incremental levels of PEG. The mean corpuscular hemoglobin concentration (MCHC) showed negative linear and quadratic effects (P = 0.008 and P = 0.003). Creatinine (P = 0.005) and calcium (P = 0.005) showed linearly positive effects. Nutrient digestibility showed positive linear and quadratic responses (P &lt; 0.05). Treating <em>S. lancea</em> with incremental levels of PEG improved growth performance and digestibility while not compromising the overall health status of Boer goats. The optimal level of PEG was determined to be 15.4 g/kg for the final weight, the weight gain, the average daily gain, and the feed conversion ratio based on quadratic responses.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107582"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770798","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":"Assessing chronic stress in sheep using wool cortisol: A comparative study of transhumant and intensive systems","authors":"Sezen Ocak Yetişgin ,&nbsp;Uğur Şen ,&nbsp;Hasan Önder ,&nbsp;Ceyhun Yücel ,&nbsp;Büşra Akça ,&nbsp;Hüseyin Mert Yüksel ,&nbsp;Ömer Faruk Yılmaz","doi":"10.1016/j.smallrumres.2025.107617","DOIUrl":"10.1016/j.smallrumres.2025.107617","url":null,"abstract":"<div><div>Chronic stress profoundly affects livestock welfare, productivity, and resilience, yet its dynamics across different production systems remain insufficiently understood. This study investigates chronic stress in Karayaka sheep within three distinct production systems—long-distance transhumance (LDT), short-distance transhumance (SDT), and intensive systems (IS)—using wool cortisol concentrations as a non-invasive biomarker. Wool samples were collected from 45 ewes and 30 lambs over an eight-month period (October, December, January, February, March, May, July, and September) to evaluate cortisol accumulation as a reflection of chronic stress. Cortisol levels were analyzed using ELISA immunoassay after steroid extraction. The results revealed significant impacts of production systems and sampling periods on cortisol concentrations (P &lt; 0.05). The marginal mean of wool cortisol was higher (P &lt; 0.05) in SDT production systems (5.49 ± 0.20 pg/mg) compared with IS (4.85 ± 0.20 pg/mg). Seasonal variations were prominent, with cortisol peaking during winter months (January–February) and declining in March (P &lt; 0.05). Notably, cortisol concentrations decreased during high-altitude summer grazing but spiked post-migration (May). Lambs exhibited lower cortisol levels (5.11 ± 0.17 pg/mg) compared with adult sheep (5.34 ± 0.17 pg/mg). Statistical analysis underscored significant interactions between production systems, sampling periods emphasizing the interplay of environmental stressors and animal physiology. These findings highlight the linkage of stress to environmental transitions and the critical need for adaptive management strategies tailored to production systems to reduce chronic stress and improve animal productivity and to advance sustainable livestock management.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107617"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044288","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":"Biochar and tannin interactions in sheep nutrition: Digestion, ruminal fermentation and nitrogen utilization in alfalfa silage-based diets","authors":"Amir Mokhtarpour","doi":"10.1016/j.smallrumres.2025.107587","DOIUrl":"10.1016/j.smallrumres.2025.107587","url":null,"abstract":"<div><div>The synergistic effects of biochar and tannin on intake, nutrient digestibility, rumen fermentation parameters, and nitrogen balance were investigated in sheep. Twenty eight adult Baluchi male sheep were randomly allocated to four dietary treatments in a completely randomized design with a 2 × 2 factorial experiment with two levels of biochar (0 and 2 %) and two levels of tannin (0 and 2 %) produced from pistachio by-products over a 28-day period. Additives were added to fresh alfalfa and ensiled for 60 days. The treatments did not significantly influence dry matter intake (DMI) or crude protein (CP) intake (P &gt; 0.05). Significant improvements were observed in CP and NDF digestibility with biochar supplementation, while tannin showed a potential trend (P = 0.06) in decreasing NDF digestibility. Ammonia nitrogen (NH₃-N) concentration increased (P &lt; 0.05) in biochar fed sheep, while tannins reduced (P &lt; 0.05) ammonia-N levels and shifted nitrogen excretion patterns. There was a tendency for higher ruminal total volatile fatty acid (VFA) concentrations with biochar supplementation (P = 0.06), whereas tannin treatment numerically decreased total VFA (P = 0.09). Sheep receiving biochar-supplemented diets exhibited a tendency for elevated acetate levels (P = 0.08) and a significant increase in butyrate proportions (P &lt; 0.05). Notably, significant interactions were found for propionate concentration and acetate to propionate ratio, indicating potential synergy. Biochar enhanced total cellulase activity predominantly in the particulate phase (p &lt; 0.05), while tannin generally reduced cellulase activity across multiple phases (p &lt; 0.05). It can be concluded that biochar and tannins exert independent effects on nutrient digestibility, rumen fermentation, and nitrogen metabolism, with biochar primarily enhancing fiber digestibility and microbial activity, while tannins reduce ammonia nitrogen concentrations and proteolysis.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107587"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827809","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":"Duddingtonia flagrans against anthelmintic resistant gastrointestinal nematodes in goats","authors":"Gabriel da Silva Correia ,&nbsp;Giancarlo Bomfim Ribeiro ,&nbsp;Gleice Cerqueira Estrela de Sousa ,&nbsp;Ially de Almeida Moura ,&nbsp;Jackson Victor Araújo ,&nbsp;Fábio Ribeiro Braga ,&nbsp;Lorendane Millena de Carvalho ,&nbsp;Wendell Marcelo de Souza Perinotto","doi":"10.1016/j.smallrumres.2025.107599","DOIUrl":"10.1016/j.smallrumres.2025.107599","url":null,"abstract":"<div><div>This work aimed to evaluate the efficacy of <em>Duddingtonia flagrans</em> against anthelmintic resistant gastrointestinal nematodes strains in goats. For this, 128 mixed meat breed animals from four different farms within the municipalities of Cruz das Almas, Cachoeira, Iaçu and Santa Bárbara, Bahia, Brazil, were used. Four groups were formed (G1 — ivermectin, G2 — levamisole, G3 — albendazole and G4 - control) to assess the susceptibility to anthelmintics, using the fecal egg count reduction test. Furthermore, coproculture was performed to identify the genera of nematodes. Quantitative coproculture was performed, in two groups: treated (<em>D. flagrans’</em> chlamydospores added) and control (without chlamydospores). All populations showed low sensitivity to the treatment with the anthelmintics. The genera <em>Haemonchus</em> showed a higher prevalence, followed by <em>Trichostrongylus</em> and <em>Oesophagostomum</em>. <em>D. flagrans</em> treatment resulted in high reduction values for helminth larvae: 95.5 %, 96.1 %, 93.2 %, 92.8 % for the populations from Cruz das Almas, Cachoeira, Iaçu and Santa Bárbara, respectively. Resistant nematode strains tested were sensitive to <em>D. flagrans</em> fungi when administered to in vitro fecal cultivations, suggesting that this feed additive may be of importance fighting against anthelmintic resistant nematode strains.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107599"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864344","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":"Development of a genetic reference flock: Benchmarking of industry and U.S. Sheep Experiment Station Rambouillet sires","authors":"Carrie S. Wilson ,&nbsp;J. Bret Taylor ,&nbsp;Thomas W. Murphy ,&nbsp;Ronald M. Lewis ,&nbsp;Whitney C. Stewart ,&nbsp;David R. Notter","doi":"10.1016/j.smallrumres.2025.107580","DOIUrl":"10.1016/j.smallrumres.2025.107580","url":null,"abstract":"<div><div>The Rambouillet breed is important throughout the U.S. because of its value in both lamb and fine wool production. The objective of this research was to benchmark performance of industry and U.S. Sheep Experiment Station (USSES) sires in an extensive rangeland production system in the development of a national genetic reference flock. Between 2015 and 2018, 13 Rambouillet (“industry Rambouillet”) and nine Merino-influenced Rambouillet (“industry Merino cross”) rams were incorporated into the USSES breeding program. The performance of their progeny was compared to 27 USSES Rambouillet rams. The final dataset included 1240 progeny records, with 313 from industry Merino cross, 294 from industry Rambouillet, and 633 from USSES Rambouillet sires. Significant differences among the three sire groups (<em>P</em> &lt; 0.05) were found for 13 of the 18 production traits. Generally, wool quality traits favored the industry Merino cross progeny over the USSES Rambouillet progeny. Growth and survival traits were similar among the three groups. When estimated breeding values from national genetic evaluation were compared for the sire groups, five of the nine measures and an economic index (U.S. Western Range Index) differed (<em>P</em> &lt; 0.05). Wool traits generally favored the industry Merino cross sires, the economic index favored the USSES Rambouillet sires, and the growth traits were similar and did not differ among the groups. Incorporating industry sires into the USSES flock allowed benchmarking of their progeny, broadening of the genetic base, and permitting development of a national genetic reference flock for use in future research.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107580"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749487","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":"Effects of different soybean and canola seed supplementation under varying concentrate levels on growth performance, lipid metabolism, and gene expression in fattening Afshari lambs","authors":"Somayeh Pashaei ,&nbsp;Taghi Ghoorchi ,&nbsp;Ahad Yamchi ,&nbsp;Reza Mirshekar ,&nbsp;Mostafa Bokharaeian","doi":"10.1016/j.smallrumres.2025.107614","DOIUrl":"10.1016/j.smallrumres.2025.107614","url":null,"abstract":"<div><div>This study evaluated the effects of dietary supplementation with ground soybean and canola seeds on growth performance, blood metabolites, carcass traits, hepatic lipid metabolism, and related gene expression in Afshari lambs. Fifty male lambs (18.8 ± 2.7 kg, 3 months old) were assigned to ten treatments based on a 2 × 2 × 2 factorial design plus two control groups. The treatments included two concentrate levels (high: 11.3 MJ ME/kg DM, 16.4 % CP; and low: 9.6 MJ ME/kg DM, 14 % CP), two oilseed inclusion rates (5 % and 10 %), and two oilseed sources (sunflower and canola), along with non-supplemented control groups for each concentrate level. Over 98 days, feed intake, body weight, feed conversion ratio, and protein efficiency ratio were recorded. Blood samples were collected every 28 days for biochemical profiling. At slaughter, carcass and organ weights were measured, liver triglycerides quantified, and hepatic expression of PPARα, CPT1, and Lipin1 assessed by qPCR. High-concentrate diets significantly increased final body weight, average daily gain, feed intake, and carcass weight (P &lt; 0.001), with minimal effects of oilseed type or inclusion on these traits. Serum albumin, triglycerides, lipoproteins, and alkaline phosphatase exhibited dynamic responses to diet and time, reflecting shifts in protein and lipid metabolism. High concentrate intake upregulated PPARα (P &lt; 0.05), whereas low concentrate diets enhanced Lipin1 and CPT1 expression (P &lt; 0.001). Liver triglyceride accumulation was greatest in high-concentrate, 10 % oilseed treatments (P &lt; 0.001), indicating that energy density, more than oilseed inclusion, governs hepatic lipid deposition. Distinct regulatory patterns were consistently observed across dietary treatments: soybean supplementation in low-concentrate diets (LS10) specifically enhanced CPT1 expression, whereas canola inclusion in high-concentrate rations (HC10) predominantly stimulated PPARα activation. These results establish that metabolic networks are independently influenced by both dietary energy density and lipid source composition Balancing concentrate level and oilseed inclusion can optimize growth efficiency and liver health in intensive lamb production.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107614"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044287","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":"Copper nanoparticles as a strategic nutritional intervention to enhance periparturient health, immunity and productivity in heat-stressed goats","authors":"Ali Afzal ,&nbsp;Naima Mahreen","doi":"10.1016/j.smallrumres.2025.107588","DOIUrl":"10.1016/j.smallrumres.2025.107588","url":null,"abstract":"<div><div>Climate-induced heat stress critically impairs the productive performance of small ruminants, especially during the periparturient period. This study evaluated the effects of copper nanoparticle (CuNPs) supplementation on physiological, biochemical, immunological, and productive responses in Beetal goats and their offspring under summer heat stress. Thirty pregnant goats were randomly allocated to three groups: control (no CuNPs), S1 (10 mg CuNPs/kg DM), and S2 (20 mg CuNPs/kg DM), monitored from 15 days prepartum to 45 days postpartum. CuNPs supplementation significantly improved thermoregulation and physiological stability. The S2 group exhibited pronounced reductions in rectal temperature, pulse rate, respiration rate, and plasma cortisol levels, alongside enhanced rumen motility, compared to the control group (P &lt; 0.05), indicating better heat stress adaptation. Biochemically, CuNPs elevated total plasma protein, globulin, and immunoglobulin levels (IgA, IgG, IgM) in both goats and their neonatal kids, while reducing plasma cholesterol concentrations (P &lt; 0.05). Hepatic and renal function markers—including AST, ALT, ALP, creatinine, and uric acid—were significantly lower in the S2 group compared to S1 and control group (P &lt; 0.05), reflecting improved organ health under thermal stress. Antioxidant status was markedly enhanced in CuNPs-treated animals, with increased activities of SOD, POD, CAT, and total antioxidant capacity (TAC) in both generations (P &lt; 0.05). Milk quality and yield were also improved; the S2 group produced colostrum and milk with higher protein, fat, total solids, copper content, and antioxidant capacity (P &lt; 0.05). Importantly, kids born to CuNPs-supplemented dams exhibited significantly higher birth weights and postnatal growth rates compared to controls (P &lt; 0.05), with the S2 group showing the most pronounced improvements, followed by S1. These findings suggest that dietary CuNPs, particularly at 20 mg/kg DM, effectively mitigate heat stress, improving health, immunity, antioxidant capacity, and productive performance in periparturient goats and their offspring.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107588"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827810","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":"Energy and protein requirements for maintenance and growth in female hair sheep","authors":"Caio Julio Lima Herbster ,&nbsp;Antonio de Sousa Brito Neto ,&nbsp;Marcos Inácio Marcondes ,&nbsp;Luciano Pinheiro da Silva ,&nbsp;Evandra da Silva Justino ,&nbsp;Izabelle Auxiliadora Molina de Almeida Teixeira ,&nbsp;Stefanie Alvarenga Santos ,&nbsp;Ronaldo Lopes Oliveira ,&nbsp;Elzania Sales Pereira","doi":"10.1016/j.smallrumres.2025.107578","DOIUrl":"10.1016/j.smallrumres.2025.107578","url":null,"abstract":"<div><div>This study aimed to estimate the energy and protein requirements for ½ Santa Ines × ½ Dorper females hair sheep. Twenty-eight females (19.50 ± 1.43 kg initial BW) were allocated in a completely randomized design with three feeding levels (<em>ad libitum</em>, 280 and 620 g/kg DM feed restriction) to a 60:40 ratio of roughage and concentrate, with a gain of 150 g/day for the <em>ad libitum</em> animals. At the beginning of the trial, four females were slaughtered as a baseline group to estimate the initial empty body weight and the initial body composition of the remaining animals. When the experiment reached day 135, all the animals were slaughtered. The net energy requirement for maintenance (NE_m) was estimated through regression analysis of heat production on metabolizable energy intake. The net energy requirement for gain (NE_g) was estimated by regressing retained energy on empty body weight gain (EBWG). NE_m was estimated at 0.323 MJ/kg^0.75 EBW/day, and the efficiency of metabolizable energy utilization for maintenance was 0.64. The NE_g increased as body weight increased. The metabolizable protein requirement for maintenance was 3.18 g/kg^0.75 EBW/day. The net protein requirements for gain decreased as body weight increased. This study highlights the importance of updating information on nutritional requirements recommendation Committees, including studies on female hair sheep, to improve the models for estimating nutritional requirements and the productive efficiency of the animals. Models generated allow for estimating body composition and energy and protein requirements for ½ Santa Ines × ½ Dorper females hair sheep.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107578"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749816","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":"Performance and feed efficiency of heat-stressed lambs of different genotypes in response to dietary lipid sources and residual feed intake status","authors":"G. Halakoo ,&nbsp;Yansari A. Teimouri ,&nbsp;M. Mohajer ,&nbsp;Y. Chashnidel","doi":"10.1016/j.smallrumres.2025.107620","DOIUrl":"10.1016/j.smallrumres.2025.107620","url":null,"abstract":"<div><div>Although supplementing dietary lipids is a common strategy to mitigate heat stress in livestock, its efficacy may depend on an animal's genetics and inherent metabolic efficiency (Residual Feed Intake; RFI). This study investigated whether performance responses to different lipid sources are co-dependent on the genotype and RFI status of heat-stressed lambs. Initially, 48 male lambs from four genotypes were evaluated for RFI. From this group, 32 lambs, classified as Low-RFI (LRFI) or High-RFI (HRFI), were selected and used in a 2 × 4 factorial arrangement to assess their response to four diets under HS: a control (no fat) and diets supplemented with Calcium Salts of Fatty Acids (CSFA), Beef Tallow (BT), or Canola Oil (CO). The results confirmed the central role of RFI: LRFI lambs were more resilient, exhibiting 12 % lower dry matter intake (P = 0.03), superior nutrient digestibility (P &lt; 0.05), and greater residual weight gain (P = 0.03) compared to HRFI lambs. While all lambs benefited from lipids (highest ADG with CSFA, P = 0.01), a crucial RFI × lipid interaction (P = 0.02) emerged. The results showed that the animal's efficiency status dictated the optimal fat source: CSFA was best for LRFI lambs, while CO was optimal for HRFI lambs. Based on the results, it appears that an animal's response to nutritional support under heat stress is dependent on both its inherent metabolic efficiency (RFI) and genetic makeup. It appears, therefore, that incorporating the RFI trait into sheep selection programs could substantially elevate the strategic importance and efficacy of tailored nutritional interventions.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107620"},"PeriodicalIF":1.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157953","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}