Maximising the Milking Capacity of an Automatic Milking System

Automatic milking offers the farmer the opportunity to milk the cows without human intervention. An important feature of automatic milking systems is the possibility to increase the number of milkings per cow per day. However, a high milking frequency does not necessarily contribute to a high output capacity in kg of milk per day, because of the more or less fixed handling time of the automatic milking system for each milking and the decreasing amount of milk per milking at short intervals. Data between October ′97 and September ‘99 from the Waiboerhoeve high-tech farm with a single unit automatic milking system were used to analyse. The average interval period between two consecutive milkings was 9.2h (SD 3.3). Respectively 14.9% and 17.7% of the milkings had an interval of 6 hours or shorter, or longer than 12 hours. Machine on time was on an average of 12.6 minutes per cow per day (SD 5.4). The overall average flow rate was 2.51 kg/min (SD 0.8) at a yield of 11.8kg (SD 4.3) per milking. The overall average flow rate could be modelled by: 2.51 kg/min + 0.05 * (Yield - 11.8). However regressions coefficients differed for low flow rate cows and high flow rate cows. Milk flow rate and yield have a large impact on capacity in kg per day. Average handling time per milking visit was 2.23 minutes. Flow rate has a positive effect on both numbers of milkings and capacity. Increasing the yield per milking will decrease the milking frequency in the herd, but will increase the capacity in kg per day for the automatic milking system. Increasing the handling time by 0.5 minutes per milking visit will lower the milking capacity per day by 5 to 8%. Cows should be prevented from being milked less than twice a day. Farm management should be focused on cow management, feeding, housing conditions and animal health in order to maximise the capacity of an automatic milking system and to minimise the costs per kg of milk produced.