Candidate genes related to reproductive traits of Hereford and Braford bulls

Abstract

This study emphasized the importance of using candidate genes in predicting semen quality in bulls that can be used in cow-calf production. The aim of this study was to evaluate some candidate genes related to reproductive traits in Braford and Hereford bulls. All bulls (n=188) were submitted to breeding soundness evaluations at 24, 28, 32, and 36 months of age. The microsatellite markers ILSTS002 and BMS3004 associated with the luteinizing hormone-? (LH?) gene, IDVGA-51 to leptin (LEP) gene, HEL5 and AFZ1 within the IGF-IR gene, and two SNP markers (LHR and FSHR) associated with the LHR and FSHR genes, respectively, were evaluated by the amplification of DNA products. The variation in the IDVGA-51 allele 177-185 showed polymorphic information content (PIC) associated with sperm motility and vigor traits in Hereford bulls. Hereford animals showed PIC of 0.36 to 0.75% along with expected heterozygosity (H) of 0.49 to 0.78%. Braford bulls that indicated the ILSTS002 allele 137-175 and AFZ1 allele 113-119 showed PIC associated with major and minor defects, respectively. The PIC ranged from 0.28 to 0.78%, with an expected H of 0.35 to 0.81%. AFZ1 allele 121-127 had the highest minor defects and ILSTS002 allele 125-135 showed the highest major defects from ejaculated semen in Braford bulls. In addition, IDVGA-51 allele 175 showed lower motility and vigor in Hereford bulls. The markers AFZ1 (IGF-IR) and ILSTS002 (LH?) in Braford and IDVGA-51 (LEP) in Hereford bulls were effective in verifying the reproductive traits of the bulls.

Keywords

• Molecular markers
• Single nucleotide polymorphisms
• Microsatellites
• Genetic variability
• Braford and Hereford breeds.