The life expectancy of ukrainian brown dairy breed cows depending on linear estimation of the udder morphological characteristics

Abstract

The Estimation of dairy cattle cows by morphological characteristics of the udder is an important element in the system of linear classifi cation of dairy cattle. This is due to the existence of a correlation between the linear characteristics of the udder and indicators of milk productivity and longevity of cows. Studies on the impact of assessing the linear characteristics of the exterior on the life expectancy of dairy cows are motivated and relevant. The exterior type of fi rst-born cows was evaluated according to the method of linear classifi cation in the leading farms of Sumy region for breeding Ukrainian brown dairy breed. According to the descriptive method of the 9-point scale, the fi ve most important morphological features of the udder in terms of selection and technological signifi cance were studied. They are:an anterior attachment, posterior attachment height, central ligament, udder depth and anterior teat location. The signifi cant infl uence of udder morphological features on the life expectancy of cows was established. Each of the evaluated linear traits aff ects the life expectancy of a cow with diff erent relative variability of estimates within a particular sex. As for the evaluating of the anterior attachment of the udder, the diff erence between the cows, rated at 1 and 8 points, was 681 days (P <0.001). The diff erence between the low (1 point) score for the height of the attachment of the udder at the back and the highest (9 points) was 610 days (P <0.001). Animals (17.3%) with a grade for the condition of the central ligament of the udder below average (1–4 points) were used from 2436 to 2156 days. Meanwhile, cows with the highest score of 9 points diff ered in longevity – 2786 days, exceeding cows with scores of 1–4 points by 350–630 days (P <0.001). Cows with the highest udder relatively to the hocks, with a score of 8, have the diff erence in life expectancy 597 days (P <0.001), compared to animals with the most lowered udder. Cows with a score for the location of the front teats had 5 points and lived longer by 156–484 days (P <0.001), compared with cows with a score of 1–4 points. Key words: Ukrainian brown dairy breed, udder, linear type traits, life expectancy.