Effect of breed, age and period of production on bovine semen quality used for artificial insemination

Various factors are believed to influence quality of semen in breeding bulls. The main objective of this study was to evaluate how breed, age and time of semen production are relevant in the production of good quality semen used for Artificial Insemination. A total of 16,827 ejaculates from 187 bulls (Holstein Frisian = 114, Jersey = 35, Borena = 12, 50%HF × 50%Borena = 5, 75%HF × 25%Borena = 15 and Fogera = 6) were collected and examined at the National Animal Genetic Improvement Institute (NAGII). All these factors (breed, age and period of production) had significant (p ≤ 0.05) effect on semen volume, colour, concentration, mass activity, individual motility and production doses/ejaculate. All these semen quality measures were significantly (p ≤ 0.05) minimal in 50%HF × 50%Borena crosses and all of them except concentration were observed superior in HF. Excluding ejaculate volume and production doses, all the semen quality measures were recorded better in the first two age classes (less than 2 and 2 to 4 years of age classes). Significance differences in ejaculate volume, concentration, mass activity, and individual motility were observed among production periods; these disparities could be due to the variation in managemental practice and efficiency of implementing the protocol in selecting candidate bulls for the time period. In conclusion, breed, age and period of semen production have significant effect on bovine semen characteristics.     Key words: Borena, cross breeds, Fogera, Holstein Frisian, Jersey, semen characteristics.