Behavioral interest of male swine for different types of environmental enrichment

Abstract

The objective of this study was to evaluate the behavior of male swine after the insertion of chains and tires as environmental enrichment in confinement. The study was carried out at the University of São Paulo, in Pirassununga-SP, Brazil. Six hybrid males, 12 to 30 months of age, were used. Chains and tires were inserted individually. The behavior and the time of interest for the enrichment was obtained observing the moment in which the animal looked for the inserted object, with direct observations, without intervals, morning and afternoon. The ambient and body temperatures were measured, with respiratory rate obtained at the beginning and at the end of the observations. Salivary cortisol was obtained by means of an individual cotton rope. Enrichment type and age analysis were performed by chi-square analysis, Pearson's correlation between body surface temperature and behavior, and t-test for respiratory rate and ambient temperature. The age of the male swine had no influence on the behavior of interest. In total, 79.86% of the males showed no interest in the chains, however, 61.11% of the males showed interest in the tire. In the control environment, 91.67% of the animals remained idle. The respiratory rate found was higher in the afternoon (P <0.05). Serum cortisol dosages were 0.5 to 3.1 ng /mL, 0.5 to 0.9 ng /mL, 0.5 to 1.2 ng/ mL and 0.9 to 1.2 ng /mL. It is concluded that the environmental enrichment in the facilities of male pigs constitutes an important tool, being the tire the best method of entertainment when compared to the use of chains.