Relationship between reproductive capacity and productive longevity of cow

Abstract

One of the most critical tasks of modern dairy farming is to extend the time of productive use of cows. Studies have shown that the studied herd’s economic benefit ranged from 1005 to 3693 days and averaged 1864. The lifetime milk yield of the cows averaged 20746 kg and lifetime milk fat was 735.4 kg. On the first day of economic use, 10.2 kg of milk was obtained, and on the first day of lactation, the figure was significantly higher at 20.8 kg. The most extended use period for a cow was found to be 1903 days. The average open days were 91-120 days. The highest lifetime productivity was obtained from this group of animals, which was 21909 kg of milk. A further reduction or increase in the length of open days was accompanied by a decrease in economic use and a decrease in the productive life of the cows. When open days were too long (more than 120 days), the productive life of the cows was reduced to 1875 days, and milk productivity was also reduced to 20562 kg of milk. According to the research results, the abundant lifetime life of cows increases with the duration of inter calving period from 11 to 13 months from 14939 to 26582 kg. It was found that productive life milk yield and milk fat decreased with a more extended period between calvings. The age of the first calving had no significant effect on the duration of economic use of the cows. Individuals with first calving at 30 months of age and more excellent than 1993.2 days were best on this trait. However, the highest productive life was shown by animals whose age at first calving was 26-27, 9 months.