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 yield and milk composition in 421 Romanian Black and White cows from the South-eastern Romania. Milk yield, milk fat yield, 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 (<25, 25-28, 28-31, 31-34, and >34 month), and 2 farms in order to study the 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 337.8 kg lactose. Milk production was significantly different in the two farms. Parity has a significant effect on the milk production; only differences between first lactation and third lactation, as well as second lactation and third lactation were statistically significant. When the age at first calving was lower or equal to 28 months, the milk production was significantly lower compared with production obtained from cows that calved at 31 months of age or later. It was concluded that the three studied factors had a significant effect on the milk production.