Effect of Breed, Month of the Year and Age of Bulls on Semen Quality of Bos Taurus Bulls in a Tropical Environment

Abstract

Ejaculates from 48 bulls comprising equal numbers of Aryshire, Fresian, Guernsey and Jersey breeds at an artificial insemination station in Kenya were analysed. The effect of age, breed and month of the year on semen volume, spermatozoa concentration and motility were studied.

The second ejaculate volumes, concentrations and motility were significantly higher (p<0.01) than the first ones. Age and breed of bulls contributed significantly to variations in ejaculate volumes, spermatozoa concentration and motility (p<0.01). The month of the year did not significantly affect semen quality.