COMPARATIVE STUDIES OF THE REPRODUCTIVE CAPACITY OF NIGERIAN AND EXOTIC POULTRY BREEDS

1. TESTIS AND SEMEN CHARACTERISTICS

Résumé

THE study involved 48 adult cocks from four breeds namely, White Rock (WR), Rhode Island Red (RIR), White Leghorn (WL) and Nigerian indigenous breed (NIB). They weighed between 1 -26kg at the beginning of the experiment. The WR cock had the heaviest paired testis Weight (25.06g) while NIB had the lightest (16.549). These weights accounted for 1.04% and 1.22% of the liveweight respectively while the specific gravity of the testis from these two breeds was 1.048. The volume (0.63ml vs 0.33ml) and progressive motility of the spermatozoa (63.34 vs 58.12%) were highest in the WR and lowest in the NIB while sperm concentration (3.03 vt 2.43 x 10') was highest also in the WR but lowest in the WL. These semen characteristics were significantly influenced by breed and time of ejaculation except with the volume in which the time effect was Insignificant. The WR semen had the lowest sperm abnormalities (10.13% while RIR had the highest (13.14%). The results however Indicate that the WR cocks ejaculated the largest quantity and best quality semen, followed in order by RIR, NIB and WL