Study regarding the influence of parity, age at first calving and farm management on the milk yield and composition in Romanian Black and White cows

The aim of the paper was to study the effects of parity, age at first calving and farm management on the milk yieldand milk composition in 421 Romanian Black and White cows from the South-eastern Romania. Milk yield, milk fatyield, milk protein yield, and milk lactose yield were studied. Cows were divided into three classes for parity (1, 2,and 3+), five classes for age at first calving (34 month), and 2 farms in order to studythe effect of these factors on milk production. Average milk production in farm 1 was 5487.9 kg milk, 200.5 kg fat,189.5 kg protein, and 261.2 kg lactose, while in farm 2 was 6701.4 kg milk, 271.1 kg fat, 234.1 kg protein and 337.8kg lactose. Milk production was significantly different in the two farms. Parity has a significant effect on the milkproduction; only differences between first lactation and third lactation, as well as second lactation and third lactationwere statistically significant. When the age at first calving was lower or equal to 28 months, the milk production wassignificantly lower compared with production obtained from cows that calved at 31 months of age or later. It wasconcluded that the three studied factors had a significant effect on the milk production