By Jamie Keyes
In the past, monkeys and rodents have been the experimental animal of choice for cognitive function research, but why not sheep? In 2010, the Department of Pharmacology at the University of Cambridge, decided to experiment with sheep. According to their research article Executive Decision-Making in the Domestic Sheep, sheep have a good memory and, not surprisingly, have never been used to research the cognitive functioning system. Sheep are also less temperamental than monkeys. Trials using sheep can be conducted more quickly (three weeks versus several months) than those using monkeys.
In a 21 day study, sheep were placed in a pen with two passage ways. At the end of each passage was a correct or incorrect choice, a bucket full of pellets or an empty bucket. As the experiment went on, the choices become progressively more difficult. Changing color of the buckets, different shaped objects in the way and switching the correct passageways challenged sheep to make the right decision that led them to pellets.
Even with all the obstacles, the study discovered the sheep were able to learn the difference between correct and incorrect choices. They were able to discriminate between passages, and showed irritability if a wrong decision was made.
The study concluded that “sheep have great potential, not only for use as a large animal model of HD (Huntington’s disease), but also for studying cognitive function and the evolution of complex behaviors in normal animals.”
Alzheimer’s and Huntington’s disease are known for disrupting the cognitive functioning system. Now, through research, sheep can contribute a way to the cure.
Morton AJ, Avanzo L (2011) Executive Decision-Making in the Domestic Sheep. PLoS ONE 6(1): e15752. doi:10.1371/journal.pone.0015752