A Comparison on Polymorphism of Beta-lactoglobulin Gene in Bos indicus, Bos taurus and Indicine×Taurine Crossbred Cattle

The study was carried out on eight Bos indicus cattle breeds namely, Sahiwal, Tharparkar, Nimari, Khilari, Deoni, Amritmahal, Hariana and Hilly cattle; two Bos taurus cattle breeds namely, Jersey and Holstein Friesian and Indicine${\times}$Taurine crossbred cattle to find out the polymorphic pattern of beta-lactoglobulin gene. The polymorphism at beta-lactoglobulin gene was detected by conducting PCR-RFLP studies on 398 bp fragment spanning over 104 bases of exon IV and 294 bases of intron IV. Two alleles A and B and three genotypes AA, AB and BB were observed in all the cattle breeds. The frequency of B allele was comparatively higher than that of A allele. The allelic frequency of A varied from 0.20 to 0.30 in Bos indicus cattle breeds and 0.19 to 0.34 in Bos taurus breeds while in crossbred cattle the frequency was estimated as 0.21. The weighted frequency of A allele was highest in Indian cattle and lowest in crossbred cattle while the frequency in taurine cattle was found to be in between indicus and crossbred cattle. The non-significant differences of allelic frequency amongst Bos indicus, Bos taurus and crossbred cattle was observed. The effect of genotype on fat percentage was also found to be non-significant in cattle.