Lamb meat, which is consumed as widely as pork, beef and poultry, has a very important place in red-meat consumption worldwide. Sheep can survive without consuming green fodder in geographies with poor pastures and very harsh continental climate conditions. In lambs reared for meat purposes, the average daily weight gain (ADG) from birth to weaning and their live weight at weaning are crucial economic traits that affect the profitability of breeders. Additionally, lamb live weight at weaning age could be vital for the lamb's subsequent live weight gain and survival rate. Therefore, improving the live weight at weaning age is desired to increase lamb meat production. However, information on animals' genetic background that affects the weaning weight is limited in many sheep breeds. The aim of this study was to investigate the association of the rs427117280 single nucleotide polymorphism (SNP) on chromosome 2 (OAR2) with live weight gain at different time points (live weight at birth and on the 30th, 60th and 90th days post-birth) in indigenous sheep breeds (Akkaraman, Şavak Akkaraman, Morkaraman, Karayaka and İvesi) in Türkiye. In total, 1973 lambs were genotyped using Custom TaqMan SNP genotyping assays for the rs427117280 SNP. Association analysis showed that lambs with a GG genotype had the highest weight on the 90th day (BW90) and the highest ADG from birth to the 90th day (ADGB-90) (P≤0.01). It was concluded that rs427117280 could be considered as a candidate quantitative trait nucleotide (QTN) for the BW90 and ADGB-90 traits. Therefore, these findings suggested that variation in the rs427117280 SNP might be used as novel genetic marker for improving pre-weaning and weaning growth traits in sheep.

In this study, it was aimed to investigate the relationship between three SNP on the BRCA1 gene and subclinical mastitis, as well as milk yields during four lactation periods in Holstein breed cattle. The animal material of the study consisted of 151 Holstein cows reared under the same care and feeding conditions. Complete DNA was isolated from blood samples by using phenol: chloroform: isoamyl alcohol method. Genotyping of G22231T, T25025A and C28300A SNPs on the BRCA1 was done by the PCR-RFLP method. Subclinical mastitis of animals was determined in milk samples by California Mastitis Test (CMT). In the study, CMT data, four lactation periods’ milk yields, and proportional distributions of SNP genotypes were calculated. Statistical significance of the data was determined by the Pearson chi-square test. The relationship between C28300A SNP, which was monomorphic, and subclinical mastitis has not been analyzed. In the samples examined, the difference between the proportional distribution of SNP genotypes of G22231T and T25025A in subclinical mastitis and healthy groups was not found statistically significant (P>0.05). As a result of the Chi-square (χ2) analysis conducted, it was observed that the Holstein cattle were in the Hardy-Weinberg equilibrium in terms of G22231T and T25025A SNPs. Considering the physiological processes in which the BRCA1 gene is involved, it was thought that these genes and SNPs should be evaluated with more samples in studies on resistance to mastitis.

Understanding the genetic factors that influence meat yield is crucial due to the economic importance of average daily live weight gain (ADWG) in livestock. This study investigates the relationship between the c.*188G>A SNP in the 3′‐UTR region of the akirin 2 gene and growth traits in Zavot cattle, focusing on the gene's role in muscle development. Genotyping of the c.*188G>A SNP was conducted using polymerase chain reaction–restriction fragment length polymorphism analysis, revealing frequencies of 0.09 for AA, 0.75 for AG and 0.16 for GG genotypes, respectively. Our findings demonstrate a significant association between this SNP and ADWG, as well as percentage. These results suggest that the c.*188G>A SNP within akirin 2 could serve as a valuable DNA marker for predicting ADWG and percentage traits in Zavot cattle.