Results of Selection for Eight-Week Body Weight in Three Broiler Populations of Chickens

Abstract

RESULTS from single-trait selection experiments are useful in the study of quantitative inheritance in general as well as to gain specific information regarding heredity of the trait studied. Several long-term selection experiments involving body size in laboratory animals have been reported during the past three decades. (MacArthur, 1949; Falconer and King, 1953; Robertson, 1955; Rahnefeld et al., 1963; Roberts, 1966a, b, 1967a, b). However, the published reports regarding response to long term selection for eight-week body weight in chickens are quite limited. The studies reported in this paper deal with the results of selection for eight-week body weight in three broiler populations of chickens. The object was (1) to compare the realized and expected response to selection, and (2) to compare the rates and limits of selection response in different populations. EXPERIMENTAL PROCEDURES Three populations of broiler stocks, designated as G, A, and AG, had been selected for increased eight-week…