Does the change in sperm motility during the production period differ between high and low motility groups?

Persistence of the semen quality and sperm function is one of the important factors in flock fertility preservation. The aim of this study was to assess the trends of semen and sperm parameters in selected cocks with superior and inferior sperm motility from Iranian native and Arian commercial line. Roosters were grouped into high (HML) and low motility (LML) at the early experiment (27 week). The trends for semen and sperm parameters were monitored during an eight-month period (30-60 weeks). Sperm motility in all groups showed an acceptable range (58-87%). The sperm motility trend of indigenous group was dissimilar to the commercial line. The trend line in the LML group from the indigenous roosters was ascending for the sperm motility, while the HML group showed a descending trend. Sperm concentration in both groups had a descending trend during the period of semen production. Sperm parameters, such as VAP, VSL, VCL, ALH and STR differed in the HML and LML groups in both strains (P < 0.05). In conclusion, selection of roosters based on the sperm motility at the early breeding is not sufficient for maintaining a desirable sire attributes and flock fertility. Therefore, increasing the rooster to hen ratio amid the production period may be a good managerial suggestion for maintaining the hen fertility and flock hatch rate.