THE INFLUENCE OF CERTAIN GENOTYPIC FACTORS ON THE DURATION AND EFFICIENCY OF HOLSTEIN LIFETIME USAGE

Abstract

Extending the duration of economic use of cows and enhance their productivity was and is now an important component of genetic improvement in many countries. The duration and effectiveness of lifetime usage of animals closely related not only to economic efficiency, but also to the selection process, since for both the production and breeding the most valuable animals are those who have these two combined successfully features. Therefore, the aim of our research was to study the effect of different linear affiliation of Holstein cows on the duration and effectiveness of their lifetime productivity, identify the best variants of interline and intrinsically linear selection of parental pairs. Studies conducted on the materials of primary breeding accounting in herds in Vinnytsia, Rivne, Cherkasy, Kirovohrad and Kyiv regions. Retrospective analysis of life expectancy and efficiency of the use of cows was performed by Yu. P. Polupana method. (2010). The analysis involved information about economic use and lifetime productivity of 2902 cows, while all animals were taken into account, first calving of which was in 1996-2008 and who left the herd after finishing the first lactation with duration at least a minimum of 240 days. It was found that in terms of duration and effectiveness of productive use indices of daughters from different bulls were different. By the life duration, productive use, number of lactations in life and the best lifetime performance were the daughters of bull Rok 373840409, and worse – Dzhokus 113080315. Rok 373840409, Lord 661287, E. Samb 3035115974, Bg. Rodeo 27642626161 and V. Astronomer 2160431 turned to be improvers by these features. The best by duration of economic usage and by lifetime productivity were animals of Treyt lines 1629391, Valiant 1650414 and Eleveysh 1491007 and cows whose mothers belonged to line R. Sayteyshn 267150 and R. Sovrin 198998. Worse than the aforementioned indices were cows of J. Besn line 5694028588 and animals whose mothers came from a line of Adem 26781. Identify the best variants to combine parental pairs with interline and intrinsically linear selection may contribute to lengthening the duration of productive use of cows and increase their lifetime productivity. Analysis of interline selection of animals showed that the most successful combination was when cows belonged to Bell lines, and bulls – to Eleveyshn line. Animals from this combination had the longest used in the herd (4,43 lactations) and they had the highest lifetime productivity (38671 kg of milk). The second position by studied parameters got cows from the combination of Starbuck-Eleveyshn (3,77 lactations and 28150 kg of milk). Long term usage and high lifetime productivity is well combined by animal from the cross of Eleveyshn-Bell lines (3,53 lactations and 22906 kg of milk). In addition, animals from cross of Valiant-Bell lines characterized by higher figures of usage duration and animals from the cross of Starbuck-Bell lines, Starbuck-Chif and Valiant-Bell had high lifetime yield. The most unsuccessful were all combinations when the mother belonged to line of Adem. Animals from these crosses were used in herds in less than 2 lactations, and their lifetime yield was 11584-13341 kg. By intrinsically linear selection in terms of duration and effectiveness of lifetime usage animals from Eleveyshn line were the best. The duration of use of these animals was 3 lactations and their lifetime yield – 24176 kg. The highest degree of impact on the studied parameters of duration and effectiveness of lifetime usage had animals with origin by the father – 51,6-55,2 %. The impact of the father line, depending on the index, was within 16,7-18,0 %, the mother line – 10,3-11,4 %.