Polymorphism in exon 3 of myostatin (MSTN) gene and its association with growth traits in Indian sheep breeds

•Exon 3 of myostatin (MSTN) gene studied in Madras Red and Mecheri sheep breeds of Tamil Nadu, India.•Identification of single nucleotide polymorphism (SNP) by restriction digestion.•Sequencing of PCR products and detection of SNP at G5622C locus of exon 3 of MSTN gene.•Genotyping by PCR-RFLP and association study with growth traits by Leasts-square analysis.•Possible use of SNP at G5622C locus of exon 3 of MSTN gene as a potential marker for selection in Madras Red sheep breed.