Heritability and Correlation Analyses of Egg Weight, Egg Shape and Egg Number in Chickens

Abstract

INTRODUCTION THE objective of the present study is to provide additional information on the heritabilities of egg weight, egg number and egg shape and the genetic and environmental relationships between the three traits. The management schedules, housing and feeding were the same during the three year period in which the data were collected but variations in ambient conditions and disease exposure occurred. It was possible, therefore, to determine the effects of variable inter-year milieux on the interrelationships of the three characteristics. Data will be presented which indicate that when natural selection is antagonistic to artificial selection, the genetic and environmental correlations between certain traits may be altered. DATA The data were collected from the University of British Columbia production flocks of New Hampshire and Single Comb White Leghorn chickens during the years of 1953–54 (1), 1954–55 (2) and 1955–56 (3). The egg weight and egg shape data . . .