STUDIES REGARDING PRODUCTIVE LIFE OF A FRIESIAN COW POPULATION
The purpose of this research was to find some methods to grow up the productive life of cows for a good profitability in the farm. The research was had been conducted on 125 Friesian cows. The results show an average milk production of 4580.70 kg in the first lactation along 305 days, reaching maximum value (5694.84 kg) in the third lactation. The first lactation is 80.43% from the maximum lactation. Is to note the big variability of milk production which is situated between 18 and 22 %. The productive life was of 824.85 days for the cows which finished the production period and the life span of cows was up to 1769.52 days. The cows from this population were milked in average by 2.96 lactation and they were kept in population for about 4.85 years. The average milk production per productive life was 13266.14 kg with 518.42 kg pure fat and 359.90 kg protein and using index was 46.61%.
Key words: Friesian, milk, life span, productive life