BACK TO QUEBEC CITY 2002 TITLES
Post-natal behavioral
and physiological responses of piglets from sows housed individually or
in groups during gestation
A.D. Sorrells1,2, S.D. Eicher1,
M.J. Harris2, E.A. Pajor2 and B.T. Richert2
1Livestock Behavior Research
Unit – Agriculture Research Service, USDA West Lafayette, USA; 2Purdue
University, West
Lafayette, USA
Sow gestation housing remains a controversial animal welfare issue. Two different types of gestation housing were used to evaluate gestation housing as a possible source of prenatal stress on piglets. Landrace x Yorkshire gilts (n=48) were randomly assigned to groups of four in pens (n=8; G; 3.9 m x 2.4 m) or to individual stalls (n=16; S; 2.21 m x 0.61 m). Gilts were moved into individual farrowing crates 5 days prior to the expected farrowing date. All piglets were weighed at birth, d3, 14, and 35. Two male representatives from each litter were weaned at d14 and housed together in pens (76.2cm x 81.28cm). Belly nosing and play/fight interactions were observed for three days post-weaning using 10-min interval scan sampling. An isolation test (30min duration) was then performed on one randomly chosen piglet from each pen on d35. Time spent lying, and the number of jumps against test box walls, grunts and squeals were recorded in real time and analyzed using the Observer® program. Salivary cortisol was collected at 30 minutes intervals from baseline (T0), T30, T60, T90, and T120. Skin surface temperature of face, back, and shoulders was recorded pre- and post-test using thermal imaging. The two identified male piglets were bled via jugular puncture on d2, 7, 14, 17, 21, and 28. Plasma was assayed for TNFa by ELISA and haptoglobin, a1-glycoprotein, and IgG were analyzed by radial immunodiffusion. Immune data were analyzed using Mixed Models in SAS® as a repeated measures design. Behavioral data, weights, and skin surface temperatures were analyzed using the GLM procedure of SAS. Piglets from S gilts weighed significantly less (10.3 kg) than G piglets (12.8 kg) only on d35 (P=0.001). Piglets from S gilts also vocalized more (squeal freq = 19, grunt freq = 356) during the isolation test than did G piglets (squeal freq = 7, grunt freq = 138) (squeals P=0.05, grunts P=0.002). However, salivary cortisol, skin surface temperatures, and immune measures were not significantly different between treatments. These data show some behavioral and production differences between piglets from individually stalled gilts and group housed gilts. Further research is required to clarify this relationship.