A nonrestrictive method for maintaining grouped swine for blood sampling applicable to physiologic assessment of stress.

Studies of the stress response in swine require repeated blood sampling to determine diurnal variations of measured parameters. Most of these methods require elaborate artificial habitats such as metabolism crates and/or physical restraint for venipuncture. In either case, the aversive nature of the sampling procedure induces activation of the hypothalamic-hypophyseal-adrenal cortical axis. The development of a nonaversive procedure for repeated blood sampling of swine is described in this paper. The pigs were unrestrained and maintained in groups in a variety of habitats.