Construction of a predictive index to create new high-value genotypes of cows

Abstract

The purpose of this study is to develop a predictive index APIndex for animals of the domestic AYRshire dairy cattle population using a genetic and mathematical model. The processing included phenotypic data of 65,753 cows from 34 breeding farms in 8 regions of the Russian Federation. According to the basic model of the I AYR index, developed in our previous studies, the proband AI AYR and parents were assessed: SIAYR — for fathers of bulls, DIAYR — for mothers of cows using our own estimates of the breeding value EBV using the BLUP AM method. Using one-way analysis of variance ANOVA, significant influences of the index assessment factors of fathers and mothers on the dependent variable of the proband index value were established, which amounted to 20.9% and 17.7%. As a result of calculating the strength of influence and regression coefficients, a predictive index for the proband was developed, which allows one to evaluate the offspring even before obtaining their phenotypic data. The quality of the developed predictive index model was confirmed by high reliable correlation coefficients with AIAYR (r = 0.807, p ≤ 0.001), SIAYR (r = 0.889, p ≤ 0.001) and DIAYR (r = 0.515, p ≤ 0.001). Thus, the constructed index APIndex can be used as a tool for predicting the index assessment of animals and obtaining new highly valuable genotypes and eliminate unwanted individuals using identified negative scores.