Medycyna Wet. 62 (6), 611-616, 2006
Olechnowicz J., Lipiński M., Jaśkowski J. M. |
Main issues in robotic milking of cows |
The time needed for cow udder preparation before robotic milking depends on the length of the preceding interval in milking and is related to the extent of udder filling. The greater this extent, the more time required for milking preparation. In multibox robots this may be as long as 2 minutes from the time of teat stimulation to the beginning of milking and causes merely a temporarily decline in the concentration of oxytocin in blood and an insignificant increase of residual milk. Robotic milking results in an increase in the frequency of milked cows, although this is rarely higher than 3 and on average ranges from 2.6 to 2.8; on the other hand, cows visit the robot between 4.9 to 6.9 times per day, and failure to attach the teat cup ranges from several to 15%. In this study the daily yield milk was intermediate (27.1 kg) between the milk production of twice (24.4 kg) and thrice milked cows (30.3 kg). After the introduction of robotic milking (especially in first 3 months) a significant increase of somatic cells (from 246 000/ml to 302 000/ml) and total bacterial amount (from 7.4 × 103/ml to 14.6 × 103/ml) was observed in the milk. During the following months the freezing point of the milk obtained in the process of robotic milking increased by about 0.007oC compared with milk obtained in the traditional manner. The content of free fatty acids in cow milk from robotic milking was also higher (-0.588 mmol/100 g fat) compared with cows milked twice (-0.893 mmol/100 g fat) and three times (-0.722 mmol/100 g fat). Significantly lower frequencies of teat skin redness traits appeared in robot-milked cows (3.9 and 6.6%) but they displayed a significantly higher frequency of dry teat skin traits (26.3 and 3.6%) than that occurring in traditionally milked cows, which additionally displayed a higher frequency of extended teat canals in the front teats rather than rear teats. Milk leakage from teats occurred more often in robotic milking (39%) than in cows conventionally milked and housed in a free-stall barn (13.2%) or a tie-stall barn (9.7%). Combining robotic milking together with grazing the cows during the summer period may be a possible method of achieving a high standard of welfare for the animals. |
Keywords: robot milking, cows, somatic cells |