Pasture management in two high performing automatic milking systems

Achieving high voluntary cow movement is one of the major challenges when adopting an automatic milking system (AMS) within a pasture based dairy system. An analysis of two commercial dairy farms with excellent cow flow was undertaken to capture a more detailed understanding of how these farms were achieving regular voluntary cow movement and target milking frequencies. Data was collected throughout January and February 2013 on two farms, located in North-West Tasmania (Farm A) and Western Gippsland Victoria (Farm B). The farms were milking on average 207 and 166 cows respectively, with three Lely A3 robots, 3 way grazing and no irrigation. On Farm A, daily pasture allocation (pre-grazing biomass – 1500) varied significantly (p<0.05) from 4 kg DM/cow for block B and C to 2 kg DM/cow for block A, which resulted in a variation in the percentage of feed allocated per hour of active access of 2.2-5.5%. This corresponded with a more uniform milking distribution over a 24 hour period, achieving between 21 and 25 milkings/hour. Farm B’s pasture allocation was not significantly different (p=0.091) between blocks, however the percentage of feed allocated per hour of active access did vary between 3.3-6.0%. This resulted in more variable milking distribution over a 24 hour period of between 9-22 milkings/hour. Thus, it is concluded that high voluntary cow movement in an AMS can be achieved by varying the quantity and timing of pasture allocation.