Effect of rearing environment and environmental enrichment on behavior and neural development in young pigs

There is increasing concern about the welfare of farm animals. In two trials, forty-eight 7.97 and 10.78 kg Hampshire-sired crossbred pigs were housed in either a complex environment (CE) or a simple environment (SE) for 9.5 weeks. The SE consisted of two pigs, in 1.22 x 1.22-m pens in a closed building. The CE consisted of 12 pigs in an outdoor pen with straw bedding, daily petting by people and a variety of objects such as cloth strips, chains, balls, boards, and newspapers. The objects were changed daily. In half the animals the somatosensory cortex was Golgi-Cox impregnated. SE pigs had greater dendritic branching and larger somas than CE pigs. Total ring intersections were 55.70 $\pm$ 2.38 and 48.62 $\pm$ 2.38, respectively. SE pigs engaged in greater amounts of belly nosing, which may have stimulated the cortex. There was no effect on visual cortex. The SE pigs were more excitable and aggressive. CE pigs approached a strange man more rapidly and were more willing to walk through a narrow chute. Further experiments indicated that the addition of small amounts of environmental enrichment to barren pens greatly reduced blind excitability ratings. Petting by a person (mingling) for 5 minutes once a week was effective. Two enrichment treatments such as mingling and objects (hanging rubber hoses) were more effective than a single treatment. Environmental effects on handling behavior were complex. In one trial, mingling and objects reduced the amount of prodding required to move pigs through a chute. In another trial, mingled pigs were more difficult to drive. There may be an optimal level of tameness for pigs which will be marketed for slaughter. In barren pens, hanging cloth strips (objects) reduced fighting in newly mixed pigs. One week of exposure to objects prior to mixing reduced biting and pulling of the objects during mixing. Previous exposure to objects prior to mixing had no effect on fighting. When objects were first introduced, activity was intense, and it leveled off at a lower level. The pigs appear to seek stimulation. Simple enrichment procedures may alleviate the effects of sensory restriction.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Grandin, Temple

Contributors dc:contributor

• Curtis, Stanley E.

• Biology, Neuroscience
• Agriculture, Animal Culture and Nutrition
• Biology, Veterinary Science

Statement dc:rights

• Copyright 1989 Grandin, Temple

Language dc:language

eng

Identifier

AAI8924824
(UMI)AAI8924824

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21967