Selecting Lambs under Farm Flock Conditions

Abstract

Four indexes for selecting lambs of Shropshire breeding were developed. These contain one or more of the three characters studied body weight, staple length and face covering. Each of the indexes was directed toward selecting for the same aggregate genotype containing the genie values of these three characters as well as grease fleece weight.The genie values of these four characters were weighted by their respective relative economic values per se and in relation to other characters which contribute to profit in the sheep enterprise. The index equivalent to body weight of the lamb at weaning minus twice face covering score is the one suggested as the most practical for farm use. Face covering is scored on a scale from one to seven with one equal to open face and seven closed face. Estimates of economic values, phenotypic and genetic correlations and heritabilities are given. Copyright © . .