Genetic conditionality of optimization of live weight at early insemination of heifers

Abstract The article describes a model for estimating the genotype of cattle developed and tested on actual livestock. The model is a selection index that takes into account the live weight of young animals aged 6 and 9 months. The average and high correlation between the indicators of live weight of young animals aged 6 and 9 months, lim rP 0.49…0.63 end rG 0.38…0.58. The Accuracy of genotype estimation (RJH) using the developed model is 0.57…0.66. The expected genetic improvement in live weight when using the index was 1.29…2.40 kg at the age of 6 months and 0.94…2.20 kg at the age of 9 months. The model allows for an early assessment of the breeding value of young animals aged 6-9 months at the level of short-term breeding programs for dairy cattle herds. In conjunction with the index assessment of ancestral indicators, it can be used in the formation of elite groups of young animals.