Exterior indices UDC and FLC as indicators of the reasons for culling of Ayrshire cows

Abstract

Research is focuses on the possibility of using udder dairy composite (UDC) and feet and legs composite indices (FLC) as indicators of the reasons for the culling of Ayrshire cows based on the results of their exterior assessment after the first calving. The processing included data on the exterior assessment and the reasons for their cull of 855 first calving cows. Almost all the correlation coefficients of indices with the classification assessment of exterior features were positive and reliable. The UDC is most correlated with the classification of the udder (0.614***) and the total score (0.535***), the least — with the dairy strength (-0.126***). The FLC is highly correlated with the classification of legs (0.940***), with the total score(0.529***), low negative and unreliable with a dairy strength (-0.033). The indices are interconnected at 0.223***. The ranking of UDC and FLC by level revealed an incomplete coincidence of the point complex assessment of some signs of the exterior. The ranking of UDC by level revealed an increase in the scoring classification of all signs of the exterior, the FLC has a mismatch. In culling cows due to limb diseases the FLC was negative (-0.44 ± 0.31) and low compared to other groups. The value of UDC with diseases of the udder is -0.06 ± 0.08. In other animals, these were neutral or positive values. Cows with negative values of both indices were identified in each group of diseases. For example, in groups with udder disease and metabolic disorders, the number of such cows is almost the same 26.0 and 26.3%, and with diseases of the reproductive organs and legs — 20.7 and 22.2%. The force of influence of the indices on retirement is η2UDC=42.0***% (F=7.6) and η2FLC=40.0***% (F=13.2). Studies have revealed predicted retirement rates with UDC and FLC data.