Pigs growing up in an enriched environment grow faster, have better immunity, and can cope with disappointments better.
That was the conclusion of a study by PhD researcher Lu Luo, attached to Wageningen University and Research, the Netherlands. An enriched pen is described as a bigger pen with straw and sawdust, for example.
In a news release, Luo’s study is described as the first to compare the long-term effects of an enriched pen with those of a standard bare pen. Luo assessed not only the pigs’ behaviour but also their growth, their immune systems and their emotional states.
Different levels of natural antibodies
The researcher discovered that pigs from enriched pens had different levels of natural antibodies than pigs from conventional pens, which probably makes them respond more effectively to infections. Her discovery ties in with earlier research findings by Ingrid van Dixhoorn, who found that pigs from enriched housing had better resistance to the Porcine Reproductive and Respiratory Syndrome virus (PRRSv).
Enrichment in pig pens could include the use of straw. - Photo: Ronald Hissink
Another significant benefit is that the pigs from enriched environments coped better with being weaned. After weaning, they ate better and grew faster than pigs in a bare environment. In addition, they displayed fewer stress symptoms and could cope with disappointment better, according to the article.
Research with 32 groups of pigs
Luo performed her research on the Wageningen campus with 32 groups of pigs. About 25% of the pigs were housed in either an enriched or a bare pen, another 25% were moved from a bare pen to an enriched one after 7 weeks, and yet another quarter were moved in the opposite direction.
The pigs that went from an enriched pen to a bare one seemed to become more stressed and began to display harmful behaviour such as tail or ear biting, which the pigs in the enriched environment hardly ever did. It also became apparent that pigs that moved from an enriched environment to a poor one were worse off than the pigs that stayed in a bare pen all the time. The pigs that were ‘promoted’ from bare pens to enriched ones showed lasting signs of improved wellbeing, playing and exploring more.