Effect of season on Ejaculate Quality of three phenotypes of Nigerian Local Cocks

Abstract

Twenty four (24) adult Nigerian local cocks comprising 8 normal, 8 frizzle and 8 naked-neck were subjected to two ejaculations per week for seven weeks in each season (early rain, lale rain, early dry and late dry seasons) using the massage technique. Ejaculates were subjected to both physical and chemical evaluations. Results showed a significant (P<0.01) seasonal effects between phenotypes in reaction time. In all the seasons, naked-neck and frizzle cocks had higher (P<0.01) ejaculate volume, sperm motility and total sperm than normal cocks. A highly significant (P<0.01) phenotype by season interaction was observed with naked-neck producing better quality ejaculates during the dry season when compared to other phenotypes. Significant (P<0.05) differences were noted in the percent abnormal sperm among the seasons. There were no significant season by phenotype interactions (P>0.05) in most of the chemical parameters (Na+1, K+1, Ca2+, Mg2+, and total protein) evaluated. However, a gradual increase in seminal protein was observed among the phenotypes with a peak during late dry season. The cations (particularly sodium, potassium and calcium) and chloride constituents of ejaculates were significantly lower during the late dry season than at most other seasons. From these results it was concluded that the naked-neck and frizzle cocks appear superior to the normal cocks in semen output and quality under the humid tropical environment.