Effect of Genotype and Age on Some Morphometric, Body Linear Measurements and Semen Traits in Nigerian Indigenous Chickens
A population of 231 roosters of the Nigerian indigenous chickens of normal feathered frizzle feathered and naked neck genotypes was evaluated for the effect of genotype and age on some morphometric body linear measurements and semen characteristics of three Nigerian chicken genotypes. 20 roosters from each genotype were evaluated for semen characteristics at 24, 28 and 32 weeks of age in relation to body weights and linear body measurements at those ages. Data were obtained and analyzed for body weights, body linear measurements and for the semen characteristics. The analyzed data showed that all the body parameters were significantly (P<0.05) affected both by age and genotypes except wattle width (WW) comb length (CL) and comb height (CH) at 24 weeks of age. Semen characteristics revealed that both age and genotype had significant (P<0.05) effects though semen colour and pH were not significantly (P>0.05) affected at 24 and 28 weeks respectively with superiority in most of the trait in the normal feathered genotype. Correlation estimates showed most traits not significantly (P>0.05) correlated. It is concluded that some level of genetic variations exist in body weight, linear measurements and semen traits in roosters of three genotypes used in this study and they can be used for breeding and artificial insemination purposes for genetic improvement.
Key words: Age, genotypes, indigenous chickens