|Teaching old cows new tricks
Automatic milking is an
exciting technological innovation facing the dairy industry in New
Zealand, with the potential to affect farming lifestyles and boost
This technology is quite well-established in Europe, where it's fairly
straightforward to train cows to move from an indoors feedlot to a
robotic milking system. However, in New Zealand, with its pasture-based
farming systems, things are not quite so simple. Tania Blackmore
whose PhD research is examining how best to help cows find their way to
the milking robot, comments that "It's not so easy to ensure that
individual animals flow smoothly from the paddock to the shed and back
to fresh pasture." Automatic milking requires cows to find their
own way to the milking shed, without being driven by humans and often
on their own, without herd-mates to follow. This means they are faced
with learning how to do this, as well as a range of new behaviours
distinctly separate from conventional milking.
This cow is wearing
a transponder (blue box) on its left foreleg, so that its movements
through the automatic milking system can be tracked by computer.
With existing research indicating that cows can perceive the colour yellow, a Waikato University research project
looked at whether cows could learn to approach a yellow stimulus
("sign" as a visual cue to the correct path that they should follow.
Firstly, cows learned to distinguish between yellow and grey signs,
learning to approach only the yellow stimulus. Why? Because it
was associated with a food reward (an example of operant conditioning).
A cow learns to associate the yellow sign with a food reward.
Cows then successfully
learned to follow the yellow sign when it was randomly located in
simple mazes. Finally, cows used the yellow sign to learn the correct
path in a series of more complex mazes, involving multiple turns and
the sort of one-way gates that the animals would have to push through
on an automated farm. What's more, once they'd learned the visual cue,
the cows were able to generalise that learning to a quite different
A cow uses yellow signs to help her to navigate through a maze.
The researchers found that
the yellow signs could indeed be used as a visual cue, and that cows
could successfully solve mazes when yellow signs were provided - but
had difficulty with this task when the signs were removed. The training
was successful, showing the potential for cows to learn to follow signs
that would make it easier for them to find their way to the milking
Interestingly, while heifers learned faster, older cows remembered what
they'd learned for longer. So you can teach old cows new tricks. But
this project involved intensive training - up to 30 days for each cow,
with 50 trials a day. This really would be impractical on a working
farm. But there are ways to apply this knowledge. Tania suggests that
one option would be to put signs on gates that can be opened: once cows
have gone through them a few times they would learn that it's not
possible to push through gates that don't have signs on them.