Effect of Calving Interval on Milk Yield and Quality Evolution during Lactation in Dairy Cows

Researches were made on 125 lactations from Romanian Black Spotted cows, aimed at studying the evolution of the interval between calving on milk quantity and quality. Data were recorded and statistically analyzed by means of ANOVA / MANOVA determining the average values and dispersion indices. Based on averages parameters of lactation curves were calculated using the mathematical model proposed by Wood, called the incomplete gamma function. The interval between calving significantly influenced (p 0.05) lactation curve aspect for the percentage of dry defatted from milk for the daily growth rate (parameter c) between calving interval 351 to 450 days and of over 450 days (0.00008). Also we’ve met significant differences (p 0.05) for the initial concentration of the percentage of total solids in milk for parameter “a ” from the interval between calving up to 350 days and calving interval 351-450 days (0.80101)