Growth and carcass fatness responses of finishing pigs to dietary fat supplementation at a high ambient temperature

An experiment involving 18 individually fed barrows weighing about 81 kg was conducted to determine the effects of a high ambient temperature (30 degrees C v. 22 degrees C) and dietary fat supplementation (100 g/kg diet of encapsulated tallow v. 0 g/kg) on growth performance and carcass fatness of finishing pigs. Digestible energy (DE) intake and growth rates were significantly lower at a high ambient temperature (P < 0.001). Dietary fat supplementation considerably increased DE intakes at a high, ambient temperature (40.0 v. 33.8 MJ/day) while slightly ina easing it at a thermoneutral temperature (53.1 v. 50.6 MJ/day). Dietary fat supplementation tended to ina ease growth rates and significantly improved the efficiency of food utilization (P < 0.01). Pigs with dietary fat supplementation exhibited greater enhancement in backfat depths, carcass fatness and internal organ far at a high ambient temperature than at a thermoneutral temperature. Linear correlation between DE intake and crude fat concentration of carcasses was statistically significant at a high ambient temperature (P < 0.01, r = 0.71). Although there appeared to be a positive correlation, it was not statistically significant at a thermoneutral temperature (P > 0.05). Crude fat concentration of the internal organs linearly correlated with DE intake (P < 0.01, r = 0.66). However, fat concentration of the internal organs did not correlate to DE intake at a thermoneutral temperature. The present study indicated that although dietary fat supplementation improved growth performance of pigs over 81 kg live weight initially in hot environments, there teas the disadvantage of excessive fat deposition in their bodies.