Paul Oludare Adetunji* and Safiriyu Idowu Ola
This study was carried out to evaluate the reproductive performance of three plumage varieties of Noiler cocks, with a view to helping both the farmers and breeders in selecting the best performing variety for rearing and further genetic improvement. Eighteen cockerels of three plumage colours (brown, black and barred) were divided into 2 replicates with 3 birds per replicate. The study lasted for 38 weeks (Feb.-Nov., 2019). Data were taken on the onset of puberty parameters (age at first sperm cell and puberty) from 16-22 weeks of age, semen quality parameters (semen volume, semen concentration, sperm output, sperm motility and sperm abnormalities) from 26-52 weeks of age and sexual ornaments’ morphometry (Comb Length-CL, Comb Height-CH, Wattle Length-WL, Wattle Height-WH and Inter Pubic Distance-IPD) from 16-24 weeks of age. Data on onset of puberty and semen quality parameters were subjected to Analysis of Covariance (ANCOVA) with body weight at puberty as a covariate while morphometry measurements were subjected to Spearman correlation analysis. The result showed that the plumage colour influenced (p<0.05) the onset of puberty in the cockerels with lower age at puberty, 155.29±2.41 days and 160.09±2.41 days recorded in brown and black cockerels, respectively compared to their barred counterpart, 167.23±2.41 days. Black cocks had the highest (p<0.05) semen volume (0.84±0.03ml) and sperm output (3.47±0.13×109/ejaculate) among the varieties. The CL and CH positively and significantly (p<0.05) correlated with semen quality parameters (r = 0.34 to 0.76), negatively related to the onset of puberty (r = -0.28 to -0.50) in brown and black cocks and IPD positively correlated with semen volume (r = 0.19 to 0.38) in all the cocks. It was concluded that all the three plumage varieties of Noiler cocks in this study produced semen of acceptable quality and volume and thus could be used for reproductive purposes. The CL, CH and IPD may be used to predict onset of puberty and some semen quality characteristics in the tested varieties of Noiler cocks.