Determination of CAST/MspI Gene Polymorphism and its Effects on 180-Day Weight in Meat Production Line of Kazakh Saryarka Lambs

Abstract

The CAST gene has been extensively studied in livestock for meat quality and growth traits. A fat-tailed Kazakh sheep, the Saryarka is characterized by a hardy constitution that allows for year-round grazing. In 2016, two factory lines (for meat and wool production) were created from the Zhanaarka type of the Sаryarka sheep breed. The aim of this study was to investigate the polymorphism of the CAST gene in lambs of the Saryarka meat production line and to evaluate associations between the CAST genotype and live weight in 180-day-old lambs. A total of 60 lambs were genotyped by the PCR-RFLP method. Two genotypes, MM and MN, were identified with frequencies of 0.59 and 0.41, respectively. According to the association analysis, lambs with the MN genotype produced significantly (P<0.01) more live weight (4.48 kg) than lambs with the MM genotype. The study was the first to demonstrate that the Saryarka breed has a genetic variation of the CAST gene and its effects on lamb live weight. Consequently, it can be said that the CAST gene could potentially be a molecular marker for the Saryarka breed to increase lamb production and be integrated into the current selection program for the breed.