Comprehensive assessment of brood Ayrshire cows based on building models of multiple-factor index of breeding value

Abstract

We present the results of research for application of multiple-factor IPK2 and IPK6 indices to Ayrshire cows which were taken into account such criteria as milk yield, milk quality (fat, protein), conformation, udder form and structure, limb quality, age of the first calving and a calving interval. The absolute index values of the cows were highly variable and ranged widely. A high variability of absolute index values provides more effective assessment and selection of cows by a range of criteria. The research showed that cows with positive complex index values differ from those with negative indices for increased milk yield, fat and protein yield, higher conformation assessment during ranking, better udder and limb structure, as well as better reproductive qualities. If based on the proposed indices, the cow selection allows creating the groups of animals with high selection differential for milk production, conformation, as well as improving the fertility of animals.