Laying performance of six pure lines of chickens and four commercial hybrids at the Agassiz Research Centre

Abstract

The Agassiz Research Centre keeps six pure lines of high-producing but non-commercial layers. Egg production, body weight, feed consumption and efficiency, and several characteristics of the eggs were measured to 60 wk of age and compared with those of four commercial white- and brown-egg hybrids. Egg production from 20 to 60 wk was highest for the four commercial hybrids, with no difference between them, and was 6 to 11% lower for the pure line white-egg layers, and 7 to 13% lower for the pure line brown-egg layers. The pure line and hybrid white-egg layers had similar body weights, but the pure line brown-egg layers weighed more than the commercial brown-egg hybrid. Feed efficiency was similar for the four hybrids and was generally better for the hybrids than the pure lines, based largely on higher egg production rather than increased feed consumption. The difference between industrial hybrids and the pure lines studied can be attributed to the selection that has been applied as well as to heterosis. Key words: Chicken, genetic resources, Agassiz layer lines