Genetic Variability of C67A, A148C, and A64G Polymorphisms in Beta-Casein, Kappa-Casein, and Beta-Lactoglobulin Milk Protein Genes in Borgou Cattle

The study of genetic polymorphism represents a valuable tool for the selection and genetic improvement of livestock production, as it enables the identification of molecular markers favorably associated with traits of interest. This study aimed to analyze polymorphisms in three genes that determine the technological properties and physico-chemical characteristics of cow’s milk, including kappa-casein (κ-casein), beta-casein (β-casein), and beta-lactoglobulin (β-lactoglobulin). Genomic DNA extracted from 90 blood samples from Borgou cattle was used to amplify target gene fragments. PCR products were genotyped using the RFLP technique with the restriction enzymes DdeI, HindIII, and HaeIII for the β-casein, κ-casein, and β-lactoglobulin genes, respectively. Results revealed three genotypes for each locus- A1A1 (0.04), A1A2 (0.22), and A2A2 (0.74) for the C67A polymorphism of β-casein; AA (0.03), AB (0.59), and BB (0.38) for the A148C polymorphism of κ-casein; and AA (0.03), AB (0.19), and BB (0.78) for the A64G polymorphism of β-lactoglobulin. The predominant allelic frequencies A2 (0.85) for β-casein C67A, B (0.67) for κ-casein A148C, and B (0.87) for β-lactoglobulin A64G suggest that this cattle breed harbors underexploited genetic potential. Given the benefits associated with these alleles, it would be appropriate to conduct further studies on a larger sample, including a correlation analysis with milk technological and cheese-making properties, to use them in marker-assisted selection to improve milk production in Benin.