Heritability Estimates of Differences in Arbitrary Embryonic Mortality Traits in Turkeys

Abstract

INTRODUCTIONSPECIFIC embryonic abnormalities in Broad Breasted Bronze turkeys which contributed to low hatchability were classified into eight groups which are referred to as traits in this paper. References to these traits or similar abnormalities in chickens and turkeys are shown in Table 1.The objective of this study was to determine the differences in the rates, relative to unhatched fertile eggs, at which these specific traits could be changed by artificial selection which was accompanied by inbreeding. Rapid changes would indicate the traits more responsive to selection.MATERIALS AND METHODSFour different strains of Broad Breasted Bronze turkeys were introduced as eggs to the University of Missouri Turkey Research Farm in 1957 and for the next six years the usual mass selection for increased body weight and improved body conformation was practiced. No attempts were made to keep the strains pure.A new objective was initiated in 1963. It…