Effects of Dietary Supplementation of Fumaric Acid on Growth Performance, Blood Hematological and Biochemical Profile of Broiler Chickens Exposed to Chronic Heat Stress

The aim of this study was to investigate the effects of dietary fumaric acid (FA) on the growth performance, hematological parameters and serum biochemistry in broilers under heat stress (HS) condition. A total number of 200 broilers were allocated to five treatments including the thermoneutral group, which was reared at standard ambient temperature and fed basal diet (CONT) and four heat-stressed groups, which were held at 32 +/- 1 degrees C aged from 22 to 42 days and fed the basal diet supplemented with 0, 5, 10 and 15 g/kg FA, respectively. On day 42, body weight and feed intake were measured and feed conversion ratio was calculated. Blood was collected for the estimation of hematological and biochemical parameters. HS impaired the growth performance, but the addition of FA made a higher final body weight, average daily gain and European broiler index in comparison with HS group. The hemoglobin concentration and packed cell volume of HS broilers were significantly lower than those of the CONT birds. Birds administered 5g/kg FA diet had significantly (p<0.05) higher erythrocyte counts and hemoglobin concentration compared with birds in the HS group fed basal diet. Also, the HS group exhibited significant increase in glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol and creatinine when compared with CONT group. Dietary 5g/kg FA increased the serum total protein, albumin, globulin, total cholesterol, high-density lipoprotein cholesterol in comparison with the HS group. In conclusion, this study demonstrated the importance of using FA as feed additives to improve the growth performance of heat-stressed broilers through haematological and biochemical regulation.