Study on pre-laying characteristics of three breeds of commercial layers in the Derived Savannah zone of Nigeria.

This experiment was conducted to study the effect of strains on productive characteristics of three genotypes of commercial pullets: Isa Brown, Bovan Nera and Dominant Black. A total number of 300 day-old chicks (100 chicks per strain) were purchased from local hatcheries. Individual body weight and linear measurements were determined from 0-20 weeks of age. There were highly significant (p < 0.01) strain differences in body weight, body length, thigh length, shank length, breast girth, feed conversion and feed efficiency. Bovan Nera recorded highest body weight, lowest feed conversion ratio and superior feed efficiency at maturity (20th week). Dominant Black on the other hand had lowest body weight, highest feed conversion and very low feed efficiency while Isa Brown recorded intermediate mean values for these traits. It was indicated in this study that regardless of strain, all the traits studied increased in mean values with advancing age of the birds. In addition, positive association between body weight and sexually maturity was established as Bovan Nera with the highest body weight at 20th week laid the first egg. The results also revealed the inverse relationship between feed conversion and feed efficiency. The former declined in mean values as the birds grew older while the latter increased simultaneously but the rate of change differs among strains. Bovan Nera was adjudged good and feed efficient because the strain had the highest mean values in body weight and feed efficiency ratio at maturity (20th week) and could be recommended to farmers for increased productivity, income generation and business sustainability.