Effect of Body Condition Score and PCR-RFLP Polymorphism of Prolactin Gene on Semen Characteristics of Buffalo Bulls(BubalusBubalis)

THIS WORK aimed to evaluate effect of body condition score on semen characteristics of buffalo bulls and identify the genetic polymorphisms of prolactin (PRL) gene as bases for selection of bulls with good breeding value.The study was performed on 60 buffalo bulls aged 2-8 years. The bulls were classified according to body condition score (BCS) into two groups. The first group of bulls was between 2 to 3 scores (n 33), while the second group was between 3 to 4 scores (n 27).Three semen collections were obtained from each animal at 15-day intervals and evaluated for volume, individual motility, live sperm % and chromatin integrity. DNA was extracted from semen for genotyping of PRL gene XbaI locus of regulatory region using PCR-RFLP technique. The results showed that, body condition score had no significant effect on semen characteristics. XbaI PCR-RFLP of PRL gene showed genetic polymorphism in 678 bp PCR fragment including two genotypes AA and BB.The genotype AA (678 bp) had high frequencies (91.67%) while the genotype BB (231 and 447 bp) had low frequencies (8.33%). There were no association between the two genotypes of prolactin gene and the studied semen parameters. It could be concluded that, BCS of buffalo bulls had no effect on semen quality. The presence of genetic polymorphism in prolactin XbaI locus of buffalo bulls may acts as a genetic marker using large number of animals.