EVALUATION OF CRATES AND GIRTH TETHERS FOR SOWS - REPRODUCTIVE-PERFORMANCE, IMMUNITY, BEHAVIOR AND ERGONOMIC MEASURES

An evaluation of reproductive performance, behavior, immunity and ergonomics was conducted for two common sow housing systems: the girth tether and crate. Littermate Yorkshire X Landrace gilts were randomly assigned to either the crate or girth tether system and they remained in that treatment for two consecutive pregnancies and lactations. A total of 171 matings resulted in 141 litters (82.4% farrowing rate). Second parity sows penned in girth tethers had 1.5 fewer piglets born and 1.3 fewer piglets weaned than sows in the crate system (P<0.05). Owing to smaller litter sizes, piglets of nursing sows in the girth tether system were heavier (P<0.01) at weaning. Immune measures showed no treatment effects. Behavioral measures indicated crated gilts and sows were more active overall (P<0.01) than girth tethered sows. In addition, sows in the gestation crate showed more (P<0.05) oral/nasal stereotypies, sitting and drinking than sows in the girth tether system. Less time was required to catch litters of piglets (P<0.05) in the girth tether than in the crate farrowing environment. We concluded that the girth tether system we evaluated was undesirable from a welfare and economic standpoint, and use should be discouraged on commercial farms. In sharp contrast, the crate systems induced no evidence of stress among our sows as measured by reproductive and immune parameters. Finally, expression of large amounts of oral/nasal stereotypies were associated with enhanced litter size.