Avoiding hypothermia in neonatal pigs: Effect of duration of floor heating at different room temperatures

The effect of different farrowing room temperatures (15, 20, or 25 degrees C), combined with floor heating (FH) at the birth site, on the postnatal rectal temperature of pigs, use of creep area, and latency to first colostrum uptake was investigated with 61 litters born by loose-housed sows. Pig rectal temperature was measured at birth, as well as at 0.25, 0.5, 1, 1.5, 2, 3, 4, 12, 24, and 48 h after birth. The drop in rectal temperature from birth to 0.5 h postpartum was less (P < 0.05) at room temperature of 25 degrees C compared with 20 and 15 degrees C. Minimum rectal temperature was less (P < 0.001) at 15 degrees C than either 20 or 25 degrees C, and the time it took for rectal temperature to increase above 37 degrees C was longer (P < 0.05) when room temperature was 15 degrees C than 20 and 25 degrees C. Rectal temperatures at 24 (P < 0.001) and 48 h (P < 0.05) postpartum were also lower at room temperature of 15 degrees C than 20 and 25 degrees C. Duration of FH (12 or 48 h) did not influence (P > 0.28) the rectal temperature at 24 or 48 h after birth. More pigs used the creep area 12 to 60 h after birth of the first pig at a room temperature of 15 degrees C with 12 h FH compared with all other treatments. During the latter part of this period, more pigs stayed in the creep area also at 20 degrees C with 12 h FH. After 60 h, more pigs (P < 0.01) used the creep area at low compared with high room temperatures (15 degrees C > 20 degrees C > 25 degrees C). Odds ratio of pigs dying before they had suckled was 6.8 times greater (P = 0.03) at 15 than 25 degrees C (95% CI of 1.3 to 35.5), whereas the odds ratio of dying during the first 7 d was 1.6 greater (P = 0.05) for 48 vs. 12 h of FH (95% CI of 1.0 to 2.57), mainly due to more pigs being crushed. In conclusion, FH for 48 h was no more favorable than 12 h for pigs because the risk of hypothermia was equal in the 2 treatments, and the risk of dying increased with the longer FH duration. Increasing the room temperature to 25 degrees C reduced hypothermia and the risk of pigs dying before colostrum intake.