Abstract

This study aimed to link the genetic variants of the sperm tail gene SPEF2 and both individual and mass motility to evaluate semen in the Iraqi Holstein bulls. This study was conducted in the College of Agriculture, University of Basrah, and the fields of the Artificial Insemination Centre of the Department of Livestock in the Abu Ghraib area/Ministry of Agriculture (25 km west of Baghdad), for the period from 11/15/2022 until 4/15/2023. The sequencing results were compared with the highest match rate in NCBI due to the occurrence of several different mutations, and the highest percentage of matching was with Chinese bulls that belong to the classification Bos taurus (Accession No. KF733182). The study's results clearly indicate a significant correlation between the polymorphism of the SBF2 gene and the rate of motility (individual and mass) in the Iraqi Holstein bulls. Therefore, this gene may be considered a molecular marker for selecting highly fertile bulls.