Objective: This study was conducted to investigate the effect of MspI polymorphism in the calpastatin (CAST) gene on hematology and selected serum biochemical parameters in Awassi lambs.
Materials and methods: CAST genotypes of 31 Awassi lambs were determined using polymerase chain reaction-restricted fragment length polymorphism method. Hematology, serum biochemical analyses, serum levels of triiodothyronine, thyroxine, and cortisol were determined using routine laboratory procedures.
Results: Two CAST genotypes were detected with frequencies of 0.65 and 0.35 for MN (three major bands of 622, 336, and 268 bp) and NN (two major bands of 336 and 268 bp), respectively. Allele frequencies were 0.49 and 0.51 for M and N alleles, respectively. Animals with MN MspI CAST genotype had significantly (p < 0.05) higher neutrophil percentage and neutrophil to lymphocyte ratio but, significantly (p < 0.05) lower lymphocyte percentage and neutrophil to lymphocyte ratio than NN MspI CAST genotype. Serum T3 and cortisol concentrations were significantly (p < 0.05) higher in MN MspI CAST genotype than the NN MspI CAST genotype.
Conclusion: Results of this study indicate that CAST gene heterozygous individuals are healthier than homozygous individual, which may explain the superiority of the CAST gene heterozygous animals in growth performance.
Keywords: Awassi sheep; calpastatin gene polymorphism; hematology; serum biochemistry; stress.