Assessment of Broiler Breeder Cocks Under Selection for Semen Quality as Influenced by Age and Body weight Changes

Abstract

The study was conducted to assess the semen quality characteristics of broiler breeder cocks under selection at young (22 - 29weeks) and adult (30 - 40weeks) ages in a pedigreed population. Data were collected on a weekly interval for body weight and semen quality characteristics (sperm volume, semen colour, sperm motility, semen pH, sperm concentration and live cell) and semen morphological defects (detached head, coiled tail, bent tail and full head) and were analyzed using the SAS statistical package. Sequel to semen collection, body weights of each cock were taken and recorded. Results obtained for body weight at the two age groups showed a significant (p <0.05) difference with the adult cocks been heavier as the age advanced. The semen quality showed a highly significantly (p<0.01) difference at all ages with the exception of live cells for the adult breeder cocks’ group where the trait showed no significant (p>0.05) difference across weeks. The semen morphological defect of young breeder cocks showed a progressive significant (p<0.01) increase with the highest defect of 21.20% at 27 weeks, while for the adult cocks, the highest defect was recorded at 30 weeks with 23% defect. It can therefore be recommended that for optimum reproductive performance of the broiler breeder cocks under selection, cocks should be introduced into hen pens or used for artificial insemination at about 26weeks of age under favourable conditions that promote optimum quality semen, which can enhance fertility and hatchability for pedigree hatching