UDC 636.082
DOI: DOI: 10.36871/vet.zoo.bio.202311017

Authors

Sergey V. Anistenok,
Olga V. Tulinova,
Russian Research Institute of Farm Animal Genetics and Breeding – Branch of the L. K. Ernst Federal Research Center for Animal Husbandry, Tyarlevo village, Russia

Abstract

The analyzed sample included data on milk yield, BV of milk yield and inbreeding of 672 cows with different reasons for culling with an average milk yield for the 1st lactation of 8601 kg of milk, which is –124 kg less than their peers, and quality indicators of 3,97 % fat and 3,32 % protein. All cows are divided into 13 classes due to retirement. On average, the inbreeding coefficient for the sample is 3,50 % with a variation in groups from 2,16 to 4,59 %. The most inferior in terms of milk yield for the 1st lactation were cows with the cause of retirement low productivity and culling (–415 kg), diseases of the udder (–222 kg) and legs (–144 kg), gynecological diseases and barrenness (–134 kg). The relationship of inbreeding with absolute indicators and BV of productive traits is low, but negative with milk yield (–0,022 and –0,014, respectively) and positive with fat content (+0,053 and +0,036, respectively) and milk protein content (+0,048 and +0,027, respectively). Using a one-way ANOVA, a high and significant effect of the breeding method and the degree of inbreeding on the milk yield and the reasons for the disposal of the analyzed animals was revealed (35,1 and 24,8 %, respectively). The distribution of cows culled for various reasons, depending on the method of breeding and the degree of inbreeding, showed that among them there are more cows crossed (59,7 %) compared to intraline (40,3 %) and the proportion of culling in the first group is higher due to gynecology and barrenness (19,1 vs. 18,5 %), diseases of the limbs (14,8 vs. 12,9 %), metabolic diseases (15,6 vs. 12,2 %). When considering the degree of inbreeding, regardless of the method of breeding, it was revealed that most of the sample are cows with a moderate degree of inbreeding (63,2 %), and 28,3 % with closely related, and in the group of moderately inbred cows for the main reasons for disposal, the proportion of animals is greater by 1,4–6,6 %. Thus, the conducted studies confirm that when selecting pairs, it is necessary to take into account not only the method, but also the degree of inbreeding in the proband.

Keywords

inbreeding coefficient, breeding method, power of influence, reasons for culling, productivity of cows