Restricted Selection Indices for Milk Yield and Growth of Kid Goats in Iraq

Abstract

Genetic improvement of local goats for milk and meat in Iraq is required to cope with the growing demands of the human population. Restricted selection index (RSI), which maximizes genetic gain in chosen traits while keeping others at zero level, is presented in Lin (1985). Also, it is known that the rate of improvement is directly related to the accuracy with which the goats are ranked, the intensity of selection, the amount of genetic variation available in the trait, and the generation interval. The objective of this study was : 1) to estimate VCV of the studied traits ; 2) to compute genetic gain when selection was on total milk yield (TMY) alone ; 3) to apply RSI for TMY in association with the kid goat weight at 6 months (WT6M),and 4) to construct RSI for increasing WT6M and kid goat weight at 12 months (WT12M) with restriction on kid goat weight at 18 month (WT18M).