Productive longevity of cows in depending on the influence of paratypical factors

Abstract

Highly productive animals are a potentially valuable resource in dairy cattle breeding, while there is a tendency to reduce the time of their economic use. The purpose of the research was to evaluate the productive longevity of cows depending on the influence of paratypical factors. The influence of some paratypical factors on the life expectancy and economic use of cows, as well as their lifelong productivity has been examined in detail in the article. Cows that were culled out of the herd between 2004 and 2024 were selected for the research inclusively, which were distributed depending on their longevity in months. In order to assess the impact of paratypical factors an analysis of the causes of cow abandonment was carried out, cow growth and development indicators, as well as cow productivity indicators and their impact on productive longevity were analyzed. It has been established that the intensive period of increase milk yield of cows during the fi rst lactation negatively affected the duration of economic use. The cows that were most productive and produced for a long time in the herd were relatively late-maturing. Thus, the age of their first fertile insemination was 15.7 months, and the milk yield for the fi rst lactation was 7648 kg of milk. Cows that were less productive but survived to 3–4 lactation were characterized by the age of the fi rst fertile insemination at 15.9–16.4 months and milk yield of 7450–7530 kg. An analysis of the causes of cow culling depending on age revealed specific features for each age group. However, there were also common causes of cows culling such as limb diseases (6.8–11.9 %), digestive system diseases (5.5–10.6 %), animal science defects (5.8–25.6 %), rupture and sprain of ligaments (3.1–12.6 %), difficult calving and complications (5.3–16.1 %), and accidents and injuries were also stable (4.8–7.9 %).