Influence of environmental temperature during late gestation and soon after birth on IgG absorption by newborn piglets

15 sows were maintained either at 18 degrees C, 37% RH (control) or 5 degrees C, 63% RH (cold stressed) from day 104 after mating until 6 h post partum, when cold-treated sows were moved to the 18 degrees C farrowing room. Piglets were taken from sows at birth and kept at 14 degrees C (cold) or 35 degrees C (thermoneutral) until 6 h of age, when they were returned to their dams. Piglets were force-fed bovine colostrum at 25 ml/kg at 0.5, 2, 4 and 6 h of age. Serum cortisol concn. of sows at 5 degrees C was significantly higher than that of controls, with concn. in both groups increasing at 36 h pre-partum and returning to basal levels within 12 h after farrowing. Piglets born to cold-stressed dams absorbed more bovine and porcine IgG, and synthesized more of their own IgG later, than did piglets born to controls. Piglets cold-stressed after birth absorbed significantly less bovine IgG within the 1st 6 h than piglets maintained at thermoneutrality during the separation period. Piglets born to cold-stressed dams but maintained at thermoneutrality after birth absorbed significantly more bovine IgG than piglets born to controls but cold-stressed after birth. Piglet IgG concn. was not correlated with dam's serum cortisol concn..