Effect of Different Levels of Chlorella Vulgaris Microalgae Extract on Performance in Heat-Stressed Broilers

The aim of this study was to compare the levels of chlorella vulgaris microalgae extract with additives on performance, carcass characteristics and blood biochemical metabolites in heat-stressed broilers. This experiment has been done using 280 one day-old Ross 308 broiler chicks for 6 weeks. This experiment has been done in completely randomized design with 7 treatments and 4 replicates. Experimental treatments were including: 1- control; 2- diet containing 0.2 g/Kg chlorella extract; 3- diet containing 0.4 g/Kg chlorella extract; 4- diet containing 100 mg/Kg vitamin E; 5- diet containing prebiotic; 6- diet containing probiotic; 7- diet containing antibiotic. Heat stress program applied from 25-42 d.Treatment 2 caused an increase of feed intake and weight gain in comparison to other treatments (P