Prediction of Response and Inbreeding under Selection Based on Best Linear Unbiased Prediction in Closed Broiler Lines

摘要

A theory for predicting the response and inbreeding under selection with best linear unbiased prediction (BLUP selection) was developed. The derivation was based on the combination of the approximation of BLUP selection by index selection (pseudo-BLUP) and the prediction theory of inbreeding under selection. The derived theory was checked by stochastic simulation. The structure of simulated population was attempted to resemble an actual closed broiler line. Based on the results, the effects on response and inbreeding when using BLUP or phenotypic selection were also examined. On the whole, the derived method gave a good prediction of selection response. Although the rate of inbreeding was seriously under-predicted when the heritability was low, themethod was found to be applicable to the trait with moderate to high heritability. With the heritability 0.34, which was the estimation in the actual broiler line, alternation of selection method from phenotypic to BLUP selection was expected to increasethe cumulative response over 10 generations by 10%, while producing threefold inbreeding. To use BLUP selection in this broiler line, optimization of selection programme in terms of the number of selected birds and the selection intensity should be required.