ESTERASE GENOTYPES AND PERFORMANCE TRAITS IN MEAT-TYPE CHICKENS

Abstract

The genotypes at a serum esterase locus were determined for 3208 female meat-type chickens. These birds belonged to three generations of six strains on which records of body-weight and reproduction traits were kept. Allelic frequencies among strains were compared and then a study was made of the relationship between esterase genotype and the following traits: body weight at five ages, age at first egg, survivor egg production, rate of egg production (%), egg weight, fertility and hatchability. Allelic frequencies did not differ in two of three years between replicate control strains but were significantly different in seven of nine comparisons between selected and control strains. Analysis of variance of paired comparisons of genotypes on a within dam family basis revealed only five of the 106 comparisons to be significant. No heterotic effects were indicated. It was concluded that the esterase genotypes studied do not have a major influence on the traits investigated.