Bolhuis used a test to measure the effect of their accommodation on the cognitive capacities of pigs. She tested the memories of 32 pigs during a test in which 4 out of 16 buckets contained pigfeed. Half of the pigs came from standard pens with little in the way of diversions, while the other half came from ‘enriched pens’ which feature more space, sawdust and branches. The test showed that all the pigs were capable of learning which buckets they needed to choose in order to get the food. But the pigs from the enriched environment learned faster than their peers from standard pens. Their working memories functioned better, Bolhuis discovered.
She concluded that pigs’ cognitive development is inhibited in standard pigpens. Pigs find it stressful to live in an environment without much entertainment, and in the long term stress has a negative effect on the memory. So an enriched environment can enhance pigs’ welfare, says the animal scientist. Her research is part of a study on optimizing the conditions under which pigs are reared in the interests of their development, health and welfare.