EFFECTS OF BREED AND SEASON ON THE SEMEN CHARACTERISTICS OF THE COCK IN THE HUMID TROPICS

Abstract

The effects of breed and season on the semen characteristics of the cock were studied using adult cocks of two breeds, barred Plymouth Rock (exotic) and the Nigerian indigenous breeds (local). Breed significantly influenced body weight and the semen quality
characteristics in favour of the exotic cocks except semen pH, which remained sliglltly alkaline and total sperm abnormality. Generally sperm cuncentration and output were depressed in the rainy season. Neither breed nor season affected sperm AChE, total protein
and phospholipid content while sperm LDH tended to be higher in the rainy season. Also AChE was significantly related to semen volume, sperm motility and sperni output while sperm protein was related to sperm LDH. The increase in the semen quality characteristic in the dry season could be related to the increase in daylength although the results generally indicate a successful all-year-round mating of breeder hens in our environment.