Effects of environmental enrichment on behavioral responses to novelty, learning, and memory, and the circadian rhythm in cortisol in growing pigs.

Previously we showed that pigs reared in an enriched environment had higher baseline salivary cortisol concentrations during the light period than pigs reared under barren conditions. In the present experiment, it was investigated whether these higher baseline salivary cortisol concentrations were a real difference in cortisol concentration or merely represented a phase difference in circadian rhythm. The effects of different cortisol concentrations on the behavioral responses to novelty and learning and long-term memory in a maze test were also studied in enriched and barren housed pigs.

Effects of strawbedding on physiological responses to stressors and behavior in growing pigs.

To study the effects of environmental enrichment on physiological responses to stressors and behavior in growing pigs, pigs were housed in either a poor environment (standard farrowing pens followed by standard rearing and fattening pens) or in an enriched environment (larger farrowing pens followed by larger rearing and fattening pens, provision of straw). Body temperature, heart rate and salivary cortisol were measured during baseline conditions and in response to relocation, isolation and restraint. Pigs housed in the poor environment performed more manipulative social behavior directed to penmates than pigs housed in the enriched environment.

Effects of regular moving and handling on the behavioral and physiological responses of pigs to preslaughter treatment and consequences for subsequent meat quality.

The effects of regular moving and handling during the finishing period on behavioral and physiological responses of pigs during preslaughter treatment and consequences for meat quality were studied. From the age of 10 wk onward, 144 pigs were housed in groups of four (two gilts and two castrates) and subjected to one of the following treatments. The Environment treatment allowed pigs to move freely for 8 min outside their home pen.

Responses of slaughter pigs to transport and lairage sounds.

The behavioral and physiological responses of pigs to transport and subsequent exposure to slaughterhouse sounds were examined. Forty-one groups of four slaughter pigs were separately loaded onto a lorry and transported for 25 min. Another 43 groups were loaded onto the lorry which then remained stationary for 25 min.