Influence of supplemental ascorbic acid on broiler performance following exposure to high environmental temperature.

The present study was conducted to determine if dietary ascorbic acid (AA) would improve growth, feed efficiency, and livability of broilers following an acute heating episode. Supplemental AA was provided in the diets at calculated levels of 0, 250, 500, and 1000 ppm, continuously. Females that received 1000 ppm exhibited significantly greater body weights at 2 and 4 weeks of age. No significant effects due to AA supplementation were observed in body weights of males. At 4 weeks of age, chicks were heated on two consecutive days by increasing the ambient temperature (38.3 C at bird level) in the production facility. Heating significantly reduced body weights in males, but not females, at 5 and 7 weeks of age. Feed conversions were increased after heating, but significant effects due to AA were not found. Ascorbic acid did not improve overall livability significantly in either sex, but heat-associated mortality was reduced in supplemented females.