1Directorate of Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai-600 051, Tamil Nadu, India
2Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy-680 651, Kerala, India
3Department of Animal Genetics and Breeding, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Namakkal-637 002, Tamil Nadu, India
4Department of Animal Husbandry Statistics and Computer Applications, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Namakkal-637 002, Tamil Nadu, India
5Department of Animal Genetics and Breeding, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Namakkal-637 002, Tamil Nadu, India
6Department of Veterinary Microbiology, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Udumalpet-642 126, Tamil Nadu, India
*Corresponding Author: R.S. Kathiravan, Department of Animal Genetics and Breeding, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Namakkal-637 002, Tamil Nadu, India, Email: drrskathiravan@gmail.com
Online published on 31 July, 2023.
Majority of the people believed that, only the native breeds have A2 milk than exotic or crossbred animals. There is no enough research on milk protein variants have been carried out in Indian zebu cattle. Present study was conducted to screen more number of crossbred cattles and buffaloes in Tamil Nadu to identify the frequency of A1 and A2 alleles in the population.
The study was conducted on 68 cattle and 172 murrah/graded murrah buffaloes to explore the polymorphic variants of β-casein gene. Genomic DNA was extracted by phenol-chloroform method. Polymerase chain reaction (PCR) was performed with allele specific primers to amplify a 244 bp long fragment of beta-casein gene and visualized in 2% agarose gel electrophoresis. The population genetic indices were calculated based on the formulas.
In the present study revealed higher level of A2A2 genotype frequency (1.00) and fixation of A2 allele in kangayam cattle and murrah/graded murrah buffalo. The observed frequency of A1A1, A1A2 and A2A2 genotypes were 0.38,0.62 and 0.00 for jersey crossbred and 0.29, 0.71 and 0.00 for HF crossbred cattle. The range of Expected homozygosity (0.50 to 1.00), polymorphism information content (0.30 to 0.38), effective number of alleles (1.00 to 2.00) and level of possible variability realization value (44.54% to 100%) reflected existence of medium genetic variability in studied population.
Allele specific PCR, Buffalo, β-casein gene polymorphism, Cattle
