The Role of DGAT1-AluI  and CAST-MspI Polymorphisms in Early Growth Traits of Morkaraman Lambs

Farm animals' birth weight and postnatal live weight gain (LWG) are essential for offspring survival and meat yield. This study investigated the relationship between DGAT1-AluI and CAST-MspI polymorphisms, DGAT1-AluI and CAST-MspI genotypic interaction and LWG in Morkaraman lambs. A total of 514 Morkaraman lambs were genotyped for DGAT1-AluI and CAST-MspI polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. The TT genotype in the DGAT1-AluI  polymorphism consistently exhibited higher birth weight and weights at 30th, 60th and 90th days compared to the other genotypes. At the MM genotype, CAST-MspI showed an association between the 30th and 60th and weaning weights. In this study, we found that the M allele for the CAST-MspI polymorphism positively influenced growth performance in sheep. However, the TT genotype in the DGAT1-AluI was associated with even better growth performance. On the other hand, we determined for the first time that the TTMN genotype interaction in the DGAT1 × CAST genes serves as a robust genetic marker for weight gain at birth and on the 30th, 60th and 90th days. In conclusion, it is suggested that the DGAT1 × CAST gene TTMN genotype interaction, identified for the first time in this study, may serve as a novel and effective marker for body weight gain in the Morkaraman sheep breed.