Exploration of Neuropeptide Y Gene Variants and its Association with Growth, First Lactation Reproduction and Production Traits in Sahiwal Cattle

Background: Neuropeptide Y (NPY), a 36-AA neurotransmitter involved in the control of appetite, feeding and energy homeostasis. The bovine NPY gene is located on chromosome 4 and consists of four exons. Earlier studies have reported that genes involved in feed intake regulation, energy production and energy regulation may affect different growth and production traits in cattle. Information associating NPY SNP to reproduction and production traits in dairy cattle is, however, limited. Hence, the present study was planned to explore SNPs in NPY gene and its possible association with reproduction and first lactation production traits in Sahiwal cattle. Methodology: DNA samples were isolated from blood that has collected from hundred and three Sahiwal cows. Three regions of NPY were amplified using designed primer pairs. The sequencing of the targeted regions was done in 103 Sahiwal cows. Least squares analysis of variance was carried out for unequal and non-orthogonal data using the technique described by Harvey ( 1990) to study effect of non-genetic factors. Significance of differences based on genotypes effect of growth, reproduction and production traits were tested by general linear models. Result: Sequence data analysis revealed two transversions in NPY gene. For these identified nucleotide variations, positions were A72073973C (intron 3) and C72068620A (intron 3). This is the first report of the presence of NPY gene polymorphism in purebred Bos indicus of Indian origin. For SNP A72073973C, performances of animals with homozygote AA genotype exhibited significantly higher milk production (P <= 0.01) and growth performance (P <= 0.05) than heterozygote genotype. Heterozygous genotype exhibited superior performance for the SNP C72068620A which was found to be significantly associated (P <= 0.05) with 18M wt, WFS, WFC, FCI and FL305DMY.