BACKGROUND: Optimal levels of minerals in the diet are crucial for improving performance and immune response against the environmental stresses.OBJECTIVES: This study was conducted to evaluate the effects of water supplementation of chelated trace mineral (CTM) on growth performance, hematology, blood biochemistry, antioxidant status, and antibody response in broilers reared under heat stress condition.METHODS: A total of 240 male Ross 308 broiler chickens were randomly allocated into one of the following five treatments (each consisting of four replicates): (1) positive control (PC; thermoneutral condition), (2) negative control (NC; heat stress condition), (3) low-CTM (NC + low CTM level in tap water), (4) medium-CTM (NC + medium CTM level in tap water),  and (4) high-CTM (NC + high CTM level in tap water). The CTM levels in the tap water for the low-CTM treatment were 0.1, 0.15, 0.3, 0.4, and 0.45 mg/bird/day on days 1-10, 11-20, 21-30, 31-40, and 41-50, respectively. The respective values were 1.0, 1.5, 3.0, 4.0, and 4.5 for the medium-CTM, and 10, 15, 30, 40, and 45 mg/bird/day for the high-CTM water.RESULTS: The average weight gain during the whole experimental period in the medium-CTM treatment was higher compared to that in the negative control treatment, but lower than that in the positive control treatment (P<0.05). The heterophil/lymphocyte ratio and total antibody titers against Newcastle disease in the medium-CTM and high-CTM groups were similar to those of the broilers in the PC group, yet better (P<0.05) those of the NC group. The serum superoxide dismutase activity was also higher (P<0.05) in the high-CTM group compared to that of the NC group.CONCLUSIONS: The results suggested that the water supplementation of CTM at a moderate level (1.0, 1.5, 3.0, 4.0, and 4.5 mg/bird/day during different rearing periods) could be a strategy to ameliorate the detrimental effects of heat stress in broilers.

BACKGROUND: In order to compensate for the elimination of antibiotics from the poultry industry, finding suitable alternatives to improve the productive traits and the health of the birds is essential. Among them, naturally occurring compounds and additives are one of the best options in this regard. OBJECTIVES: The aim of this study was to evaluate the effects of sodium humate and probiotic application and their interactions on feeding broiler chicks on biochemical, immunological and blood metabolites of broiler chicks. METHODS: 336 male broiler chicks (Ross 308) were used from 1 to 42 days old. A 3×2 factorial experiment on the basis of completely randomized design was done with four replications. Experimental factors were: three sodium humate levels (0, 0.35 and 0.45% of diet) and two probiotic levels (0 and 0.02% of diet). RESULTS: The best feed conversion ratio was obtained at the finisher 1 and 2 and the whole period at the use of 0.35% of diet (P ≤0.05). The highest live weight of the last course was obtained in the treatment of 0.35% sodium humate in diet (P ≤0.05). The production index improved at a level of 0.35% of sodium humate compared to other treatments (P ≤0.05). The percentage of carcass was higher in the group receiving probiotic and sodium humate than the control group. The abdominal fat pad percentage was lower in the probiotic and humate sodium group than in the control group (P<0.05). In terms of interactions, villi length was highest in treatments receiving 0.35 of sodium humate and 0.02% of probiotic in  diet, as well as 0.45%  of sodium humate and 0.02%  probiotic in  diet (P<0.05). The highest levels of SRBC and G-type immunoglobulin were obtained in groups receiving 0.45% sodium humate and 0.02% probiotic in diet. CONCLUSIONS: In conclusion, use of sodium humate about 0.35% and probiotic 0.02% in diet of broiler chicks improves the growth performance, carcass traits  and morphological characteristics of the intestine.