Comfortable Quarters for Pigs in Research Institutions

Temple Grandin

Department of Animal Science, Colorado State University
Fort Collins, CO 80523, USA

Under natural circumstances pigs live in small maternal groups of three to five sows with some juveniles (Frädrich, 1974). Gestating sows will temporarily leave the group, root a shallow hole in the ground and build a nest with branches and soft material, and give birth in seclusion (Stolba and Wood-Gush, 1989). Pigs spend most of their time foraging and eating. Rooting is a very important behavior, and individuals may show it with a frequency of about 60 times per 24 hours. A pig's snout and the rooting-disk is the universal tool for this animal. The rooting-disk consists of as many tactile receptors as a human hand and enables the pig to carefully explore the environment and search for food on and under the surface of the ground. Pigs are highly motivated to root, and will redirect this behavior to substitute objects - such as penmates - in a barren environment (van Putten, 1979).

Pigs are conspicuously sensitive animals who require special attention to guarantee their physical and behavioral well-being in the often stressful environment of a research institution. A stressed pig will yield stressed research data of little or no value, while a well kept and carefully handled pig is more likely to yield reliable research data of scientific value.    


Figure 1. Author petting pigs. Contact with people produces calmer animals. The white cloth strips provide the pigs with opportunities for chewing and playing. The animals prefer soft pliable enrichment objects such as cloth strips to hard objects such as chains.


Figure 2. Preparturient sows have a strong instinct to build a nest for their piglets (Photo by Diane Halverson, Animal Welfare Institute, Washington, DC).


Figure 3. Pigs have a need for social companionship. Access to straw will help prevent behavioral problems (Photo by Diane Halverson, Animal Welfare Institute, Washington, DC).

      Pigs form stable groups, but there is a tendency to fight if unfamiliar animals are placed together. Tailbiting and overt aggression are common results of mixing, particularly if done in confined spaces. To avert this, pigs should be mixed on neutral territory (Wolfenshohn and Lloyd, 1994). There are welfare advantages in reducing aggression by grouping unfamiliar adult pigs after dark and subsequently providing ad libitum food to reduce aggression at feeding (Barnett et al., 1994).


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Temple Grandin wrote her widely recognized Ph.D. thesis on the effect of rearing environment and environmental enrichment on behavior and neural development in young pigs. Sheis Assistant Professor of Animal Science at Colorado State University. Her extraordinary sensitivity for the needs of animals have made her an internationally respected consultant to the livestock industry.

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