EVALUATION OF SEMEN CHARACTERISTICS INFLUENCED BY BREED, AGE AND ESTIMATION OF THE GENETIC PARAMETERS FOR SEMEN QUALITY TRAITS OF NIGERIAN INDIGENOUS CHICKENS RAISED IN HUMID TROPICS

Abstract

Much focus has been on other productive traits while less attention had been paid to semen traits in both commercial and local breeds of chicken. The reproductive traits of improved Nigeria local chicken were evaluated using three genetic groups (GG) identified as GG1 (normal feathered x normal feathered), GG2 (naked necked x naked necked), and GG3 (naked necked x normal feathered). A total of 45 cocks (15 cocks from each genetic group) were used and study lasted for 8 months. Semen traits evaluated include: semen volume and pH, sperm concentration, morphology, motility, proportion alive and viability. Data were analysed using multivariate analysis for the semen traits and genetic parameters were estimated using pooled data from the genetic groups. The result showed that genetic group significantly (p<0.05) influenced all semen traits except semen volume, pH and sperm viability. Age of cocks also affected (p<0.05) semen quality. Positive and highly significant (P<0.01) moderate to very strong phenotypic correlations ranging from 0.29 (semen volume and semen pH) to 0.94 (active motility and live sperm) were found among the semen traits. Repeatability estimates were high for semen pH, normal morphology, sperm concentration and semen volume indicating that selection of cocks based on these traits can be done with single or few observations. Based on the present findings, the three genetic groups studied could be used as parent stocks for local chicken poultry production in Nigeria.