Alcune considerazioni sulla situazione riproduttiva negli allevamenti di bovine da latte in provincia di Milano

The 6-month study involved 244 farms and 21 780 Italian Friesian cows. The distribution of cows in parities 1-8 was 29.0, 23.3, 17.7, 12.2, 7.8, 4.8, 2.8 and 1.4% resp. The calving interval averaged 401.2 days, the service period 117.6 days, and the number of inseminations per conception 1.8. The Fertility Status Index, as proposed by Esslemont [ British Veterinary Journal 133, 346] averaged only 33.6%. The CR, insemination index and service period were all significantly better on smaller compared with larger farms, and on farms with lower rather than higher milk yield.