Effect of lactation stage and milking frequency on milk yield from udder quarters of cows
The aim of the study was to analyse daily milk yield from udder quarters of automatically milked primiparous and multiparous cows during lactation and with changing milking frequency. The daily milk yield of udder quarters was higher in multiparous than in primiparous cows. At the same time, differences were observed, especially in front and rear quarters, and also in left and right quarters. The front quarters (LF and RF) of primiparous cows produced an average of 6.75 and 6.71 kg milk, and those of multiparous cows by 0.78 and 0.51 kg milk more, respectively. Higher daily milk yield was characteristic of rear quarters: 8.22 kg (left) and 7.71 kg (right) in primiparous cows, and 10.06 and 10.47 kg in multiparous cows, respectively. With advancing lactation (from ≤100 to >300 days), the milk yield of all quarters was found to decrease. The lowest decrease was in left front quarters (by 3.40 kg) and the highest in right rear quarters (by 4.35 kg). This relationship was most evident in cows entering lactation (in the first lactation period of ≤100 days). As milking frequency increased, the milk yield of individual quarters increased markedly. In front quarters, left and right quarters showed similar milk yields for milking frequency of less than 2.50 times/day and more than 2.80 times/day. A similar relationship was observed for rear quarters. The contribution of front and rear quarters to daily production was 45.8–54.2% in primiparous cows and 41.8–58.2% in multiparous cows.
Keywords: Milk, multiparous, primiparous, quarter milking