Abstract

The objective of this present study was to investigate relationships between the growth hormone gene restriction fragment length polymorphism (RFLP) and bull sperm characteristics. A total of 89 bulls from two semen evaluation stations were genotyped for the bovine growth hormone (bGH)-AluI polymorphism by polymerase chain reaction and followed by 4% metaphor agaros gel electrophoresis. The overall allele frequencies for two L and V alleles were 0.50, respectively. The relationship between the bGH-AluI polymorphism and semen characteristics was evaluated according 1500 ejaculated records. Five sperm characteristics were analyzed. Sperm characteristics showed significant variability in relation to bGH genotypes. LL bulls had a lower ejaculated volume and higher percentage of live sperm, and VV bulls had higher fresh sperm concentration and minimum effect after cryopreservation. This polymorphism could be further used for semen evaluation process in artificial insemination program in Iranian Holstein bulls.

Key word: Semen characteristics, growth hormone (GH) polymorphism, Holstein bulls.

Abbreviation

GH, Growth hormone; bGH, Bovine growth hormone; RFLP,restriction fragment length polymorphism; Leu, leucine; Val, valine; AI, artificial insemination; PCR, polymerase chain reaction; bp, base pair; dNTP, dinucleotide triphosphate; MgCl₂, magnesium chloride; ng, nano-gram; 1X, one time; kDa,centigrade  kilodalton; GLM, generalized linear model.