Pasture-based automatic milking sys

Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between
milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation
of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow
traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were
randomly assigned to two treatment groups (n = 90/group) with a 22 Latin square design. Each group was either offered treatments of
kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental
period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over
treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean 18
L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and
consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture
allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation)
relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest
that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an
allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of
alternative forages. (Key Words: Automatic Milking System, Cow Traffic, Pasture, Soybean)