REASONS FOR HOLSTEINIZED BLACK-AND-WHITE AND HOLSTEIN CATTLE DISMISSION DEPENDING ON THE INBREEDING LEVEL

Abstract

The aim of the study is to investigate the influence of the inbreeding level on the causes of culling. The paper presents the results of the analysis of the influence of the inbreeding level on the causes of cul-ling in the population of Black-and-White and Holstein cattle in the Moscow Region (n = 31,835). The inbreeding coefficient (Fx) was calculated using the Wright-Kislovsky formula. Three groups were formed: the first (n = 25,320) included those with Fx = 0.2–1 %, the second (n = 6,214) with Fx = 1.01–6.25 %, and the third (n = 301) with Fx = 6.27–31.25 %. A systematic increase in the percentage of culling due to limb disease, gynecological diseases, other non-infectious diseases, bronchopneumonia, udder injuries, salpingitis, necrobacteriosis, abortion, and old age is noted. A wave-like increase in the reasons for leaving by groups was noted: metabolic disorders from 7.57 % in the first to 7.64 % in the third group; gynecological diseases – from 6.37 to 7.31; zoobrac – from 5.46 to 5.65; mammary gland diseases – from 4.30 to 6.65; low productivity – from 2.94 to 3.32; limb injuries – from 0.49 to 1 %. The percentage of exterior defects increased from 0.15 % in the first group to 0.21 % in the second, abomasum displacement, rumen acidosis, invasive diseases and pyometra also tended to increase and amounted to 0.07 and 0.13 %; 0.06 and 0.08; 0.04 and 0.08; 0.004 and 0.02 %, respectively. It can be concluded that the increase in the level of inbreeding affected the percentage of cows culled on dairy complexes in the Moscow Region. A reliable difference was noted between all groups according to the Bartlett test and Cochran's Q test at a significance level of α = 0.05.