effect of milking frequency in early lactation on milk production, some blood metabolites and reproductive performance of holstein dairy cow

the objective of this study was to evaluate the effect of different milking frequencies in the first 6 weeks of lactation on milk production and milk constituents, blood metabolic profiles and reproductive performance of fresh dairy cows. the milking frequencies imposed were three times daily milking for 42 days (3x), six times daily milking for the first 21 days of lactation and three times daily subsequently (6x-3x) and six times daily milking for 42 days. for this purpose 21 multiparous holstein dairy cows were allocated to three groups based on bcs, parity, and body weight. results showed that the mean of milk and fcm production was significantly higher for 6x than 3x cows in first and second 21 days and in the entire period. among milk constituent only fat production was affected by milking frequencies. the milking frequency had no effect on mean dmi. weight loss of the cows was higher for 6x cows (-32 kg) than those the 6x-3x (-29 kg) and 3x (-29.1 kg). blood concentration of nefa was affected by milking frequencies and it was significantly higher for 6x compared to 3x. the mean concentration of blood progesterone and reproductive parameters was not affected by milking frequencies. it was concluded that 6 time milking per day in a short term period may inrease holstein dairy cows’ performance without any adverse effect on their reproductive parameters.