Small Ruminant Research最新文献

{"title":"Use of real-time ultrasound measurements of fat thickness and longissimus thoracis muscle characteristics for predicting body fat depots in crossbred hair ewes","authors":"José Carlos García-Cigarroa ,&nbsp;Armin Abelardo Luna-Mendicuti ,&nbsp;Jorge Rodolfo Canul-Solís ,&nbsp;Luis Enrique Castillo-Sanchez ,&nbsp;José Herrera-Camacho ,&nbsp;Einar Vargas-Bello-Pérez ,&nbsp;Alfonso J. Chay-Canul","doi":"10.1016/j.smallrumres.2024.107400","DOIUrl":"10.1016/j.smallrumres.2024.107400","url":null,"abstract":"<div><div>This study aimed to predict body fat depots using ultrasound measurements (USM) of fat thickness and <em>longissimus thoracis</em> muscle characteristics in crossbred hair ewes. A total of 24 animals with a mean body weight (BW) of 37 ± 4 kg and a body condition score of 2.39 ± 0.49 were used. USM was recorded 24 h before slaughter and included: subcutaneous fat thickness (SFT), area (LTMA), amplitude (LTA), and depth (LTD) of the <em>l. thoracis</em> muscle and kidney fat thickness (µKFT). After slaughter, the internal fat (IF) was separated, classified, and weighed as mesenteric (MF), omental (OF), or pelvic fat (PF). The left half was then separated into subcutaneous and intermuscular fat (CF), and the muscle and bone tissues were weighed separately and adjusted to take account of the whole animal. Total body fat (TBF) was determined to be the IF plus the CF weights. LTA and LTMA correlated poorly to moderately with fat depots (0.37 ≤ r ≤ 0.74, P &lt; 0.05). Other than CF, µKFT showed poor to moderate correlation with the other depots of body fat (0.44 ≤ r ≤ 0.75, P &lt; 0.05). The regression model used to predict MF had r² of 0.87 (RSD=0.14 kg) and included BW and LTMA (P&lt;0,05). OF and PF were predicted with r² of 0.55 and 0.44, respectively, including µKFT (RSD = 0.20 and 0.17 kg). IF was predicted by empty BW, LTMA, and µKFT with r² as 0.81 (RSD=0.30 kg). For TBF, EBW and LTMA explained 72 % of its variation (RSD= 0.59 kg). USM of fat thickness and <em>l. thoracis</em> muscle characteristics can improve the accuracy of predicting body energy reserves in crossbred hair ewes.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107400"},"PeriodicalIF":1.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662975","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":"The effect of an antioxidant supplement based on selenium, electrolytes, and vitamins on relieving transportation stress in goats","authors":"C. Devaraj,&nbsp;V. Sejian,&nbsp;C.G. Shashank,&nbsp;M.V. Silpa,&nbsp;R. Bhatta","doi":"10.1016/j.smallrumres.2024.107392","DOIUrl":"10.1016/j.smallrumres.2024.107392","url":null,"abstract":"<div><div>This study aimed to evaluate the efficacy of an antioxidant supplement (Transcare) based on selenium (Se), electolytes, and vitamins to relieve transportation stress in Nandidurga goats. Thirty 8–10-month-old Nandidurga female goats were randomly divided into two groups: non-supplemented (NS) (n=15) and supplemented (S) (n=15). S goats received orally antioxidant powder at a dose of 0.7 g/kg BW, dissolved in 10 mL drinking water, 45–60 min before the seven-hour trip. The antioxidant supplementation influenced <em>(P &lt;</em> 0.05) respiration rate and pulse rate after transport, head and shoulder temperature, mean corpuscular hemoglobin before transport, lymphocytes after transport, monocytes after transport, cortisol, aldosterone, tri-iodothyronine, thyroxine, glucose, HSP70, HSP90, and HSP27 after transportation. Antioxidant supplementation decreased transportation stress in Nandidurga goats.Thus, oral antioxidant supplementation proved beneficial and promising in alleviating transportation stress. Therefore, promoting such supplements among resource-poor farmers may help reverse the financial loss experienced due to transportation stress in goats.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107392"},"PeriodicalIF":1.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662619","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":"The relationship of anogenital distance with fertility and anti-müllerian hormone in Awassi and Cukurova meat ewes","authors":"Metehan Kutlu ,&nbsp;Halef Doğan ,&nbsp;Murat Durmuş","doi":"10.1016/j.smallrumres.2024.107390","DOIUrl":"10.1016/j.smallrumres.2024.107390","url":null,"abstract":"<div><div>The aim of the present study was to determine the relationship of anogenital distance (AGD) with fertility and the serum concentrations of estrogen and anti-müllerian hormone in Awassi and Cukurova meat ewes. Fifty five Cukurova meat ewes and 46 Awassi ewes were used in the study. Before sponge insertion, AGD of all ewes were measured with a digital caliper. For each breed, they were divided into two AGD categories: short AGD group and long AGD group. A sponge containing 60 mg medroxyprogesterone acetate was applied intravaginally on day 0, and remained <em>in situ</em> for 12 days. On the 12th day, sponges were removed and eCG (500 IU per ewe) was administered intramuscularly. Blood samples were collected from all ewes on day 0 and at the onset of estrus. Estrous rate, conception rate, pregnancy rate, lambing rate, multiple birth rate, litter size and male rate were calculated in all groups and breeds. No significant difference were detected in the parameters between the groups (<em>P</em>&gt;0.05). It is stated that AGD was found not to affect AMH or estrogen levels (<em>P</em>&gt;0.05); however linear regression showed a positive correlation (<em>P</em>=0.03) between AGD and estrogen on the day of estrus in the Awassi ewes. It is stated that AGD is not associated with fertility in Awassi and Cukurova meat ewes, but there is a relationship between AGD and estrogen level in Awassi ewes.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107390"},"PeriodicalIF":1.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578075","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":"Comparison of the efficacy of Sandwich ELISA with PCR for detecting Peste des Petits Ruminants in sheep and goats","authors":"Abdul-Hakeem A. Sheet ,&nbsp;Safwan Y. Al-Baroodi ,&nbsp;Mohammad O. Dahl","doi":"10.1016/j.smallrumres.2024.107387","DOIUrl":"10.1016/j.smallrumres.2024.107387","url":null,"abstract":"<div><div>The primary objective of this study was to investigate the diagnostic performance of sandwich ELISA compared to the RT-PCR technique in detecting Peste des Petits Ruminants (PPR) infection in clinically diseased sheep and goats. A secondary objective was to compare the results of N-gene- and F-gene-based RT-PCR in identifying PPR infection. Blood samples and nasal swabs were collected from 400 animals (335 sheep and 65 goats) exhibiting clinical signs of PPR in different flocks in Nineveh governorate, Iraq. Serum samples were tested using s-ELISA, whereas nasal swabs were tested using RT-PCR. The analysis indicated that s-ELISA, N-gene RT-PPR, and F-gene RT-PCR had 43 %, 40 %, and 34 %, respectively, positive results. The diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic odds ratio of s-ELISA were 0.93, 94 %, 92 %, 88 %, 96 %, and 185, respectively. A total of 25 (16 %) samples positive with N-gene RT-PCR tested negative with F-gene RT-PCR. In conclusion, although we performed RT-PCR using nasal swabs and s-ELISA using serum samples, s-ELISA can be a practical test alternative to RT-PCR for detecting PPR infection in serum samples from sheep and goats observing clinical signs of the disease.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107387"},"PeriodicalIF":1.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662700","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 mutation in myostatin exon 3 on growth and carcass characteristics of Savak Akkaraman sheep","authors":"Bulent Kar ,&nbsp;OZ Bahar ,&nbsp;Ferit Can Yazdic ,&nbsp;Altug Karaman","doi":"10.1016/j.smallrumres.2024.107386","DOIUrl":"10.1016/j.smallrumres.2024.107386","url":null,"abstract":"<div><div>The <em>myostatin</em> gene (<em>MSTN</em>) is one of the main regulatory genes involved in muscle growth and development in many animals. This study aims to determine the variations in the exon 3 region associated with <em>MSTN</em> expression in Savak Akkaraman sheep and analyze their relationship with growth characteristics. Molecular analyses (RLFP, Real-Time PCR and DNA sequencing) were performed using DNA and RNA isolations from 70 different sheep blood and meat samples. As a result of the study, exon 3 region analysis was performed using NgomIV, <em>Alu</em>I, <em>Dra</em>I, <em>Hae</em>III and <em>Msp</em>I restriction endonucleases to determine the genetic diversity in Savak Akkaraman sheep breed. Two genotypes (MM and Mm) were detected for <em>MSTN/MspI</em> and a monomorphic mm genotype indicating the conserved exon 3 region for <em>MSTN/HaeIII</em>. Additionally, four new Single Nucleotide Polymorphisms (SNPs) were detected at different positions (164th, 204th, 347th, and 441th) in the working exon region. Two of these SNPs (204th T→G: isoleucine→ methionine and 347th C→A-G: proline→glutamine-arginine) caused amino acid changes. In expression studies, it was determined that <em>MSTN</em> gene expression was higher in female sheep than in male sheep (p&lt;0.05). The MM genotype (<em>MSTN/MspI</em>) was significantly associated with increased weight gain and <em>MSTN</em> expression, while TT genotype at SNP 204 and GG genotype at SNP 347 was found to be associated with meat yield and growth traits (p&lt;0.05). As a result, the genetic differences and functional effects of the new genotypes determined in this study may shed light on breeding strategies aiming to increase meat production.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107386"},"PeriodicalIF":1.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578074","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":"Evaluation of pregnancy toxemia in goats: Metabolic profile, hormonal findings, and redox balance","authors":"Murat Uzti̇mür ,&nbsp;Cennet Nur Ünal","doi":"10.1016/j.smallrumres.2024.107385","DOIUrl":"10.1016/j.smallrumres.2024.107385","url":null,"abstract":"<div><div>Pregnancy toxemia entails the development of hyperketonemia due to the negative energy balance that occurs in the last trimester of pregnancy in dairy goats. There are a limited number of studies on new diagnostic biomarkers and the pathophysiology of pregnancy toxemia in goats. This study assessed the hormones spexin and irisin and redox biomarker and metabolic profile changes in goats with pregnancy toxemia. The study included 36 hair goats, with 12 in the subclinical pregnancy toxemia (SPT) group, 12 in the clinical pregnancy toxemia (CPT) group, and 12 in the control group (CG). Spexin, irisin, and insulin hormone concentrations were determined by ELISA, while metabolic profile parameters were evaluated with an automatic chemical analyzer and redox balance by spectroscopy. In the goats with pregnancy toxemia, serum levels of spexin, irisin, insulin, and glucose were significantly lower than those of CG goats. The SPT group had significantly higher ischemia-modified albumin concentrations than CG goats, while the CPT group had significantly lower native thiol concentrations compared to CG animals. The concentrations of beta-hydroxybutyric acid and non-esterified fatty acids in the groups with pregnancy toxemia were significantly higher than those of control animals. In the diagnosis of pregnancy toxemia, spexin had sensitivity of 90 %, specificity of 95 %, and an area under the curve value of 0.988, while irisin had sensitivity of 90 %, specificity of 91 %, and an AUC value of 0.979. In this study, both spexin and irisin hormones showed excellent performance in the diagnosis of pregnancy toxemia. In addition, pregnancy toxemia was found to cause increased oxidative stress and significant changes in metabolic and endocrine metabolism in goats. Measuring these biomarkers in both healthy dairy goats and those with pregnancy toxemia may contribute significantly to the management and diagnosis of herd health.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107385"},"PeriodicalIF":1.6,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554447","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":"Estimates of genetic parameters and genetic trends for growth traits in Menz sheep under community-based breeding programs","authors":"Shanbel Besufkad ,&nbsp;Shenkute Goshme ,&nbsp;Aschalew Abebe ,&nbsp;Asfaw Bisrat ,&nbsp;Ayele Abebe ,&nbsp;Tesfaye Zewdie ,&nbsp;Chekol Demis ,&nbsp;Erdachew Yitagesu ,&nbsp;Derib Aydefruhim ,&nbsp;Zeleke Tesema ,&nbsp;Solomon Gizaw ,&nbsp;Tesfaye Getachew ,&nbsp;Barbara Rischkowsky ,&nbsp;Mourad Rekik ,&nbsp;Berhanu Belay ,&nbsp;Maria Wurzinger ,&nbsp;Johann Sölkner ,&nbsp;Aynalem Haile","doi":"10.1016/j.smallrumres.2024.107384","DOIUrl":"10.1016/j.smallrumres.2024.107384","url":null,"abstract":"<div><div>The main objectives of this study were to estimate genetic and phenotypic parameters for growth traits in Menz sheep under community-based breeding programs (CBBPs). Data used in the study were collected from five Menz CBBPs villages during 15-year period (2009–2023). Studied growth traits were birth weight (BW), weaning weight (WW), six-month weight (6 MW), yearling weight (YW), Average daily gain from birth to weaning (ADG1), average daily gain from weaning to six months (ADG2) and average daily gain from six months to yearling (ADG3). Fixed effects were estimated using the GLM procedure of SAS 9.4. Genetic parameters were estimated fitting different univariate animal models using Average Information Restricted Maximum Likelihood (AI-REML) procedure with WOMBAT software. The most appropriate model for each trait was determined applying likelihood ratio tests. Model including only direct additive genetic effect was the most appropriate model for BW, YW, ADG2 and ADG3, whereas model including direct additive and maternal additive genetic effect without taking into account covariance between them was the most appropriate for WW, 6 MW and ADG1. Based on the most appropriate models, direct heritability of BW, WW, 6 MW, YW, ADG1, ADG2 and ADG3 were 0.29 ± 0.01, 0.45 ± 0.01, 0.46 ± 0.02, 0.42 ± 0.02, 0.44 ± 0.01, 0.75 ± 0.02 and 0.21 ± 0.02, respectively. The estimated maternal heritability were 0.04 ± 0.01, 0.02 ± 0.01 and 0.02 ± 0.01 for WW, 6 MW and ADG1, respectively. Additive coefficient of variance were ranged from 9.53 % for BW to 33.02 % for ADG2. Moderate to higher estimates of direct heritability and additive coefficient of variation (CV_A₎ in the current study indicates higher potential for genetic improvement of studied traits through direct selection. The genetic trend for the Menz sheep's six-month weight in Molale CBBPs village reveals a promising annual growth rate of 0.20 kg. Optimizing the ongoing breeding program into specializing-sire producer groups and applying intensive selection on the sub-nucleus flock could improve the efficiency of the breeding program. Genetic correlations among the studied traits were ranged from −0.50 for ADG-ADG2 to 0.98 for WW-ADG1. Genetic correlation between 6 MW and other studied traits was positive and moderate in magnitude. To achieve optimum genetic gain, the implemented selection criteria for Menz sheep (6 MW) should be continued.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"241 ","pages":"Article 107384"},"PeriodicalIF":1.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593857","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":"Behavioural and neuroendocrine responses in alpacas (Vicugna pacos) to the shearing procedure","authors":"Monika Budzyńska ,&nbsp;Joanna Kapustka ,&nbsp;Anna Stępniowska","doi":"10.1016/j.smallrumres.2024.107383","DOIUrl":"10.1016/j.smallrumres.2024.107383","url":null,"abstract":"<div><div>Shearing is a necessary procedure which can cause stress in alpacas. Reactions to stressful situations can include behavioural and physiological changes in an animal's effort to maintain homeostasis. There has been limited investigation on stress mechanisms in terms of behaviour and physiological changes in alpacas, with a focus on heart rate and cortisol in faeces and saliva. This study aimed to determine alpaca behaviour and the concentrations of selected neuroendocrine indicators (cortisol, dopamine, noradrenaline, serotonin, thyroxine) at: pre-shearing (3 days before shearing), on the day of shearing and post-shearing (5 and 10 days after shearing). This study examined 20 alpacas. Compared with the behaviour observed before shearing, shearing performed by the standing method caused only an acute behavioural stress response on the day of shearing and no change 5 and 10 days after shearing. Higher stress activity during shearing was not strongly correlated with the intensity of their everyday reactions to the environment. In contrast, noradrenaline increased and thyroxine decreased after the shearing procedure, changes indicative of mid-term stress symptoms. There were significant correlations between some behavioural and neuroendocrine indicators, confirming the involvement of cortisol, serotonin and noradrenaline in the mechanisms of alpaca behavioural regulation.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"240 ","pages":"Article 107383"},"PeriodicalIF":1.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529868","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":"Influence of additive and maternal effects on growth traits in Deccani sheep through Bayesian inference","authors":"Yogesh B. Kandalkar ,&nbsp;Yogesh C. Bangar ,&nbsp;Poonam ,&nbsp;Rakesh Nehra ,&nbsp;Ravindranath G. Nimase","doi":"10.1016/j.smallrumres.2024.107381","DOIUrl":"10.1016/j.smallrumres.2024.107381","url":null,"abstract":"<div><div>The aim of this study was to estimate genetic parameters for growth traits in Deccani sheep using Bayesian inference. A dataset comprising pedigree information and growth trait records from 2590 Deccani animals, born to 127 sires and 836 dams between 2011 and 2020, was analyzed. The growth traits considered included birth weight (BWT), weaning weight (WWT), and weights at six (SWT), nine (NWT), and twelve (YWT) months of age. Genetic evaluation employed six univariate animal models incorporating direct and maternal effects, implemented through THRGIBBS1F90 and POSTGIBBSF90 programs. Fixed factors adjusted in the analysis included year of birth, sex of lamb, season of lambing, and dam’s age and weight at lambing. Bayesian estimates of direct heritability, under the best model, revealed values of 0.14±0.05, 0.13±0.01, 0.20±0.04, 0.15±0.06, and 0.18±0.05 for BWT, WWT, SWT, NWT, and YWT traits, respectively. Corresponding maternal heritability estimates were 0.07±0.02, 0.08±0.01, 0.02±0.01, 0.10±0.02, and 0.17±0.06. Negative genetic correlations between additive and maternal genetic effects ranged from -0.99 to -0.70, while maternal permanent environmental influences were negligible. Positive and moderate to high genetic correlations among growth traits suggest potential relationships between them. These findings suggested selection based on WWT because it is measured early in life, and has high correlation with other body weight especially SWT trait.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"240 ","pages":"Article 107381"},"PeriodicalIF":1.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529734","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 for Mycoplasma ovipneumoniae nasal DNA copy number provide progress to promote domestic and bighorn sheep coexistence on public lands","authors":"Carrie S. Wilson ,&nbsp;J. Bret Taylor ,&nbsp;Michelle R. Mousel ,&nbsp;Stephen N. White ,&nbsp;Lindsay M.W. Piel ,&nbsp;Hailey Wilmer ,&nbsp;Brenda M. Murdoch","doi":"10.1016/j.smallrumres.2024.107382","DOIUrl":"10.1016/j.smallrumres.2024.107382","url":null,"abstract":"<div><div>Discord between domestic sheep producers and bighorn sheep conservationists primarily involves concerns over the transmission of <em>Mycoplasma ovipneumoniae</em> between domestic and wild sheep. To discern if selective breeding within the Rambouillet could serve to reduce transmission, a genetic approach utilizing an existing phenotype was evaluated for additive genetic variance. The phenotype employs the measure of nasally shed bacterial DNA, or <em>M. ovipneumoniae</em> nasal DNA copy number (MONCN). Following estimation of the additive genetic variation associated with MONCN, the heritability and repeatability for this trait was calculated. The level of MONCN was measured at least three times per year at the U.S. Sheep Experiment Station (USSES) from ewes ranging from 1 to 7 years of age. Repeated measures animal models were evaluated from 320 ewes with a total of 1223 samples (mean = 3.8 per ewe). The MONCN values ranged from 0 (non-detected) to 71,654 copies per 2 μl of extracted nasal swab DNA. Four genetic models were evaluated with the categorical model having the highest heritability (0.12 ± 0.09) and repeatability (0.60 ± 0.05). Fixed effects included season/year (n = 9) and ewe age (n = 7). Outcomes from this research resulted in heritability estimates from which breeding values can be estimated to select USSES ewes and rams for reduced MONCN. This research provides a practical approach that can be immediately implemented to manage domestic sheep to be more compatible with bighorn sheep on public lands, providing positive welfare benefits for both species.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"240 ","pages":"Article 107382"},"PeriodicalIF":1.6,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433461","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}