{"title":"Validation of gestational age by developing formulae and assessing embryonic and fetal development by ultrasonic fetometry in Bangladeshi crossbreed (Jamunapari × Black Bengal) goats","authors":"Khadija Begum , Md Ahaduzzaman , Azizunnesa","doi":"10.1016/j.smallrumres.2025.107629","DOIUrl":"10.1016/j.smallrumres.2025.107629","url":null,"abstract":"<div><div>The study was designed to estimate the gestational age (GA) and determine the appropriate parameters related to gestational stages in Jamunapari cross breed goats (Jamunapari × Black Bengal), conducted at Chattogram district, Bangladesh. For this purpose, six different gestational parameters [gestational sac diameter (GSD), gestational sac length (GSL), crown- rump length (CRL), trunk diameter (TD), bi-parietal diameter (BPD) and placentome diameter (PD)] were checked by ultrasonography at different stages of pregnancy. Goats (n = 150) were used for pregnancy diagnosis by trans-abdominal ultrasonography. Pregnancy was confirmed by the presence of amniotic fluid, fetal heartbeat, fetal ribs, femur, trunk etc. The gestational age was estimated statistically (EGA) and compared to actual GA (AGA). GSD, GSL, PD and CRL were significantly different between estimated and actual gestation age while PD did not vary significantly up to the second trimester of pregnancy. At early stage of pregnancy, GSD, GSL and CRL did not show significant variation between estimated and actual gestational age. PD and BPD in mid pregnancy while TD in late pregnancy were not significantly different between EGA and AGA. Significant relations were detected between actual pregnancy stage and certain parameters at different stages of pregnancy. The EGA, when calculated with a margin of ±1–5 days, did not significantly vary in estimating the expected date of delivery (EDD) across all measured parameters, except for TD when subtracting 1–5 days. The study concludes that GSD, GSL, and CRL are highly reliable for estimating gestational age in the first trimester; BPD, TD, and PD are reliable in the second trimester; and TD is most reliable in the third trimester. The EDD may vary by ±1–5 days when using the derived equations for all six parameters, but it may vary by ±4 days specifically when using TD measurements.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107629"},"PeriodicalIF":1.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270366","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}
Lorena Jamila Alves Ferreira Guimarães , Letícia Steves dos Santos , Tatiane Pacheco Barenco de Oliveira , Raymundo Rizaldo Pinheiro , Maria Leonora Veras De Mello , Juliana Patrão de Paiva , Carla Holandino , Argemiro Sanavria , Nathalie Costa da Cunha , Mário Felipe Alvarez Balaro
{"title":"Homeopathic intervention enhances osteoarthritis management and productivity in dairy goats with Small Ruminant Lentiviruses: A triple-blind, placebo-controlled study","authors":"Lorena Jamila Alves Ferreira Guimarães , Letícia Steves dos Santos , Tatiane Pacheco Barenco de Oliveira , Raymundo Rizaldo Pinheiro , Maria Leonora Veras De Mello , Juliana Patrão de Paiva , Carla Holandino , Argemiro Sanavria , Nathalie Costa da Cunha , Mário Felipe Alvarez Balaro","doi":"10.1016/j.smallrumres.2025.107628","DOIUrl":"10.1016/j.smallrumres.2025.107628","url":null,"abstract":"<div><div>Small ruminant lentiviruses (SRLV) impact productivity, health, and welfare. With no effective treatments available, homeopathy offers a safe, low-cost, residue-free alternative. This study evaluated two distinct homeopathic protocols, a homeopathic nosode (Gnosode) and a homeopathic complex of plant/mineral origin (Ghomeopathic), using a triple-blind, placebo-controlled design in SRLV-infected goats. Forty-two Saanen goats with SRLV-confirmed chronic osteoarthritis and weight loss were randomly assigned to three groups: SRLV nosode (Gnosode; n = 14), homeopathic complex (Ghomeopathic; n = 14), or placebo (Gplacebo; n = 14). Treatments were administered orally (1 mL/day) for 90 days. Monthly assessments included clinical exams, joint ultrasound, and milk production records. Both homeopathic groups showed significant improvements (p < 0.05) in body condition score, weight, articular index and joint width compared to placebo. Ultrasound revealed lower carpal joint lesion measures in treated groups, including reduced distance from the joint capsule to the subchondral space, area, and perimeter of lesions (p < 0.05). Homeopathic treatments improved clinical and ultrasound outcomes, as well as productive parameters, in SRLV-infected goats. These results suggest homeopathy as a promising tool for managing chronic osteoarthritis and weight loss associated with SRLV.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107628"},"PeriodicalIF":1.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269325","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}
Marykutty Thomas , Jinty Sukumaran , P.M. Rojan , M.R. Akhila , J. Saalom King , K.A. Bindu
{"title":"Mitogenomic characterization and phylogenetic insights into Attappady Black goats of South India: Evidence of matrilineal affinity with Iranian bezoars","authors":"Marykutty Thomas , Jinty Sukumaran , P.M. Rojan , M.R. Akhila , J. Saalom King , K.A. Bindu","doi":"10.1016/j.smallrumres.2025.107627","DOIUrl":"10.1016/j.smallrumres.2025.107627","url":null,"abstract":"<div><div>Attappady Black goats, reared by tribal communities in South India, have adapted to extensive grazing in mountainous forest ecosystems, undergoing natural selection-driven evolution. However, their genetic origins and phylogeographic history remain largely unexplored. In this study, we report the first complete mitochondrial genome sequence of Attappady Black goats to elucidate their matrilineal ancestry, genetic diversity and evolutionary relationships. The 16,641 bp mitogenome exhibits the typical caprine mitochondrial architecture, comprising 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and two ribosomal RNAs (rRNAs). A total of 20 single nucleotide polymorphisms (SNPs) were identified in the coding region, including three non-synonymous SNPs, with two located in the cytochrome c oxidase subunit III (COX3) gene and one in NADH dehydrogenase subunit 6 (ND6), suggesting potential functional implications. Additionally, a novel homoplasmic dinucleotide deletion was detected in the 16S rRNA gene. While most tRNAs exhibited a conserved cloverleaf secondary structure, tRNA-Lys lacked a complete D-arm and tRNA-Ser displayed a truncated D-arm, indicative of lineage-specific structural adaptations. Phylogenetic analysis revealed a closer matrilineal affinity of Attappady Black goats with Iranian bezoars than with other domestic goat breeds, suggesting a distinct evolutionary lineage. These findings provide valuable insights into the mitogenomic diversity, structural adaptations and evolutionary history of Attappady Black goats, contributing to a deeper understanding of caprine domestication and phylogeography.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107627"},"PeriodicalIF":1.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269326","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":"Income over loss: How management systems lower mortality and increase farm incomes from small ruminants in urbanizing Africa","authors":"Faizal Adams , Amos Mensah , Ebenezer Donkor , Ayat Ullah , Antoinette Simpah Anim-Jnr , James Osei Mensah , Seth Etuah , Gifty Boakye Appiah","doi":"10.1016/j.smallrumres.2025.107626","DOIUrl":"10.1016/j.smallrumres.2025.107626","url":null,"abstract":"<div><div>Small ruminant (sheep and goat) production is often promoted as low-labor and low-investment, yet empirical evidence on how management systems affect performance in urban and peri-urban contexts remains limited. This study investigates the determinants of management system choice among livestock farmers and evaluates the causal effects of these systems on mortality rates and farm income. Using data from 400 randomly sampled farmers in Ejisu and Juaben (Ashanti region, Ghana) during April–May 2024, we employed a multinomial logit model to analyze system adoption drivers. A multinomial treatment effect model further isolated the causal impacts of management systems on outcomes. Results indicate that 50.5 % of farmers use free-range systems, 30 % semi-intensive, and 20 % intensive systems. Key determinants for adopting semi-intensive or intensive systems over free-range include: gender, education, herd size, extension service access, primary occupation, religious affiliation, marital status, engagement in non-farm businesses, and market proximity. Critically, semi-intensive and intensive systems significantly reduced mortality rates and increased farm income compared to free-range systems. These findings demonstrate that targeted investments in livestock infrastructure (e.g., housing), veterinary services, extension support, and technical training can enhance productivity and economic returns for smallholders. To ensure sustainable urban small ruminant production, policies must be context-specific, accounting for the distinct requirements of each management system. Additionally, the extensive or free-range systems could be improved by adopting animal tethering on communal lands to reduce mortality rates.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107626"},"PeriodicalIF":1.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223128","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":"Machine learning-based prediction of pre-weaning lamb survival using animal-, housing-, and management-related factors","authors":"Bulent Ekiz, Pembe Dilara Kecici, Hulya Yalcintan, Alper Yilmaz","doi":"10.1016/j.smallrumres.2025.107625","DOIUrl":"10.1016/j.smallrumres.2025.107625","url":null,"abstract":"<div><div>The aim of the study is to classify lambs that will survive or die before weaning by using animal- and farm-related factors as predictors through machine learning (ML) algorithms, and to identify potential risk factors associated with lamb mortality in housed management systems. Survival records from birth to weaning of a total of 5539 lambs were analysed from ten farms, which reared Kivircik sheep. To predict whether the lambs will survive from birth to weaning, Decision Tree (DT), Random Forest (RF), K-Nearest Neighbors (KNN), Naïve Bayes (NB), Boosting, Logistic Regression (LR), Support Vector Machine (SVM) and Multilayer Perceptron (MLP) classifiers were tested. The survival of lambs in the raw dataset was 91.7 %. The highest accuracy (0.925) in classifying living or dead lambs was obtained by Boosting algorithm, while the second highest performance (accuracy of 0.897) was shown by RF. NB, LR, and SVM algorithms achieved relatively lower classification accuracies, ranging between 65 % and 67 %. According to the Boosting algorithm, birth weight was identified as the variable with the highest relative influence with 43.4 %. It was followed by birth month (12.2 %), number of ewes per shepherd (11.2 %), floor space per ewe (10.0 %), and birth rank group (7.0 %). In conclusion, Boosting algorithm demonstrated high classification accuracy in predicting lamb survival. Moreover, the strong predictive influences of birth weight, number of ewes per shepherd, floor space per ewe, and birth rank group indicate the importance of focusing on gestational nutritional management, husbandry conditions, and overall herd management practices in developing intervention strategies to reduce lamb mortality in housed management systems.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107625"},"PeriodicalIF":1.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160354","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":"Replacement of soybean meal with camelina meal in diet of fattening lambs: Influence on feed intake, performance and ruminal fermentation parameters","authors":"Zahra Jooshakipour , Daryoush Alipour , Mohammad Javad Abarghuei , Hassan Aliarabi","doi":"10.1016/j.smallrumres.2025.107621","DOIUrl":"10.1016/j.smallrumres.2025.107621","url":null,"abstract":"<div><div>This study evaluated the effects of replacing soybean meal (SBM) with different levels of camelina meal (CM) on feed intake, growth performance, nutrient digestibility, ruminal fermentation, and estimated microbial nitrogen synthesis (EMNS) in fattening Grey Shirazi lambs. Thirty-two lambs (95.0 ± 10.0 days old; body weight of 28.5 ± 1.3 kg) were individually housed for 83 days. Experimental diets were Con (control, diet without CM), CM33 (diet containing 33 % DM of CM instead of SBM), CM66 (diet containing 66 % DM of CM instead of SBM) and CM100 (diet containing 100 % DM of CM instead of SBM). The DM, EE, NDFom, ADFom and ADL contents of CM were higher than in SBM and the ash, CP, NFC and ME contents were lower than those of SBM. There was a tendency for increased dry matter intake (DMI) and final BW in lambs nourished with the CM33 diet compared to the control diet (L = 0.053 and Q = 0.013 respectively). The highest values of gain and average daily gain (ADG) were observed in lambs consuming the CM33 diet (Q = 0.012 and Q = 0.0012). The 66 % CM diet enhanced feed conversion ratio (FCR) (Q = 0.041). Lambs fed the 33 % CM diet exhibited greater DM and OM digestibility than other groups (DM: L = 0.014, Q = 0.028; OM: L = 0.109, Q = 0.028). The pH, total VFA, butyrate, isobutyrate, valerate, and isovalerate levels did not differ between lambs fed SBM and different levels of CM (P > 0.05). No significant variation was detected in ruminal NH<sub>3</sub>-N production between lambs fed the CM33 or CM66 diets and those receiving the control diet. Lambs fed the 33 % CM diet showed a trend toward lower ruminal NH₃-N compared to those fed the control diet (L = 0.002, Q = 0.024). In lambs fed the 33 % CM diet, acetate concentration (C = 0.037), acetate:propionate ratio (C = 0.028), and methane production (C = 0.024) decreased, while propionate concentration increased (C = 0.022) compared to the control diet. Lambs receiving the CM33 diet exhibited a higher EMNS than those fed the control diet (Q = 0.038 and C = 0.011). Regarding SMB, CM inclusion at varying levels significantly diminished protozoal counts and subfamilies of <em>Entodiniinae</em> and <em>Diplodiniinae</em> (L < 0.0001). The population of <em>Isotricha</em> (L = 0.011<em>)</em> and the subfamily of <em>Ophrioscolecinae</em> (L = 0.002) decreased only in the CM100 diet compared to the control diet. This study demonstrates that CM can replace SBM up to 100 % of dietary DM in lamb diets without compromising performance, with 33 % inclusion yielding optimal improvements in efficiency and sustainability. These findings, coupled with camelina's agronomic advantages in water-limited conditions, suggest that CM represents a sustainable alternative to SBM in ruminant production systems.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107621"},"PeriodicalIF":1.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223258","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}
Assemu Tesfa , Mengistie Taye , Aynalem Haile , Zerihun Nigussie , Dina Najjar , Shigdaf Mekuriaw , Suzanne van Dijk , Shimels E. Wassie , Andreas Wilkes , Dawit Solomon
{"title":"Systematic review on the impacts of community-based sheep breeding programs on animal productivity, food security, women's empowerment, and identification of interventions for climate-smart systems under the extensive production system in Ethiopia","authors":"Assemu Tesfa , Mengistie Taye , Aynalem Haile , Zerihun Nigussie , Dina Najjar , Shigdaf Mekuriaw , Suzanne van Dijk , Shimels E. Wassie , Andreas Wilkes , Dawit Solomon","doi":"10.1016/j.smallrumres.2025.107622","DOIUrl":"10.1016/j.smallrumres.2025.107622","url":null,"abstract":"<div><div>This systematic review was conducted to appraise the impact of community-based sheep breeding programs in Ethiopia on animal genetic improvement, household food security, women’s empowerment, and to identify integrative climate-smart interventions. The review includes 51 documents from databases such as PubMed, AJOL, CAB Direct, Web of Science, and Google Scholar, together with grey literature and institutional reports. Community-based breeding programs (CBBP) in Ethiopia provide a participatory approach that empowers farmers by addressing the limitations of crossbreeding and nucleus breeding programs. CBBP have brought significant improvements in growth and reproductive traits, food security, and women empowerment. Compared to baseline values, the intervention resulted in a 3.63 %, 5.6 %, 7.58 %, and 7.25 % improvement in birth weight, weaning weight, six-month weight, and yearling weight, respectively. Besides, litter size was improved by 0.09, and lambing intervals and age at first lambing were reduced by 21.31 days and 75.68 days, respectively. These gains has got translated into improved household livelihoods and food security through increased income from the sale of improved animals. Since 2019, seven women-led CBBPs comprising 486 members have been established, enhancing women’s participation in small ruminant breeding. For the implementation of small ruminant breeding, including CBBPs, 16 stakeholders with 34 linkages were identified. However, apart from research centers, kebele experts, and projects such as the International Center for Agricultural Research in the Dry Areas (ICARDA), most institutions have contributed little, largely due to unclear institutional frameworks. This gap has resulted in the malfunctioning of several CBBP villages. Despite notable achievements, the program continuous to face technical, financial, and institutional challenges persist. Strengthening CBBPs through the integration of climate-smart strategies remains critical for ensuring long-term sustainability and reducing greenhouse gas emissions.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107622"},"PeriodicalIF":1.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223127","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":"Molecular characterization and phylogenetic analysis of Pulex irritans (Siphonaptera: Pulicidae) fleas collected from sheep in Sivas Province, Türkiye","authors":"Zuhal Önder , Batuhan Aşkım Arslanhan , Sümmani Çifci","doi":"10.1016/j.smallrumres.2025.107624","DOIUrl":"10.1016/j.smallrumres.2025.107624","url":null,"abstract":"<div><div>Flea infestation in sheep is a significant public health concern due to their widespread distribution worldwide and the transmission of flea-borne diseases. In this study, we aimed to identify and molecularly characterize <em>P. irritans</em> collected from sheep, using morphological, molecular, and phylogenetic analysis. Flea samples were collected from sheep on six farms in Sivas Province, Türkiye, between April and September 2024. The flea specimens were morphologically identified using identification keys. After total genomic DNA extraction and Polymerase Chain Reactions (PCR), the PCR products were sent for sequencing. This morphological study indicated that from the 250 adult fleas collected from sheep, 223 specimens (110 female and 113 male) belonged to the human flea, <em>Pulex irritans.</em> Also<em>,</em> mt-COI gene region Blast analysis results confirmed that all samples were <em>P. irritans</em>. Additionally, molecular analysis revealed a high sequence similarity (99.8 %) with <em>P. irritans</em> isolates from Iran and Australia, which are available in GenBank. Considering the relatively high frequency of presence of this ectoparasite in the sheep, further studies focused on the possibility of being a vector of pathogens and their distribution between these animals and humans are recommended. The results of this study can be used to identify flea-borne disease risks and develop effective control measures.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"253 ","pages":"Article 107624"},"PeriodicalIF":1.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160452","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}
Juan Alberto Quintero-Elisea , Héctor Armando Olguín-Arredondo , José Vicente Velázquez-Morales , César Cortez-Romero , Antonia Henández-Trejo , Jessica Beatriz Herrera-Ojeda , Gaspar Manuel Parra-Bracamonte
{"title":"Follicular development in Pelibuey ewes in different seasons determined by ultrasonography","authors":"Juan Alberto Quintero-Elisea , Héctor Armando Olguín-Arredondo , José Vicente Velázquez-Morales , César Cortez-Romero , Antonia Henández-Trejo , Jessica Beatriz Herrera-Ojeda , Gaspar Manuel Parra-Bracamonte","doi":"10.1016/j.smallrumres.2025.107623","DOIUrl":"10.1016/j.smallrumres.2025.107623","url":null,"abstract":"<div><div>The aim of the present study was to evaluate estrous behavior and follicular development in Pelibuey ewes at different seasons of the year. One hundred and twenty ewes were synchronized with intravaginal progestogen sponges maintained for 12 days. The day 0 (day sponges were removed), the onset and interval to estrus were detected and follicular development was measured over four consecutive days. The variables evaluated were: the time of onset of estrus, interval to estrus and number of follicles. To determine the effect of the season on the response variables, a Chi-square test and an analysis of variance were performed for a randomized complete block design. The results indicate that season affected (P < 0.01) the incidence of estrus; it was the highest in autumn and winter (100 %) and lowest in spring (70 %). Season also influenced (P < 0.01) the number of small (class 1) follicles on Day 1 and the number of large (class 3) follicles on Day 3. In each case, follicle number was higher (P < 0.01) in spring compared with the other seasons. It is concluded that the estrous activity and follicular dynamics in Pelibuey sheep is manifested largely during the winter season. Furthermore, onset of estrus and follicle class number are significantly related to seasonal effects. The reproductive activity is observed in Pelibuey ewes during all the year.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"252 ","pages":"Article 107623"},"PeriodicalIF":1.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157951","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}
G. Halakoo , Yansari A. Teimouri , M. Mohajer , Y. Chashnidel
{"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 , Yansari A. Teimouri , M. Mohajer , 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 < 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":"2025-09-19","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}