Swine Genetic Evaluation and Selection Programs12

Abstract

Summary Swine selection procedures which utilize not only each animal’s performance but also performance of relatives can potentially increase the rate of genetic improvement by increasing the accuracy of selection. Four criteria are: (1) accurate evaluation of both young and old males and females, (2) timeliness of data analysis and summarization, (3) ability to account for possible biases including prior genetic selection and assortative mating, and (4) practical considerations concerning computer memory requirements and cost. Best linear unbiased prediction (BLUP) procedures provide accurate predictions of genetic merit by simultaneously predicting breeding values and adjusting for fixed effects. Simplified BLUP procedures including the reduced animal model (RAM) with recursive prediction or SHORT-CUT BLUP provide accurate genetic evaluation with reduced computer memory requirements. Multivariate BLUP can be simplified or reduced by the use of canonical transformations. The use of multivariate BLUP genetic evaluations in conjunction with quadratic bioeconomic objectives should result in the selection criteria which will maximize selection response. Seedstock producers should select their replacements relative to the intended use of their descendants in commercial crossbreeding systems. For this reason, three indexes are suggested: a terminal sire, general, and dam-breed (maternal) objective. With the implementation of a comprehensive genetic program, alternative selection programs including the intense selection of dams for a maternal objective can further increase genetic progress.