Effects of additive containing probiotic, vitamin C and betaine on growth performance of three commercial broiler strains under heat stress condition by using multiple attribute decision making method

.This study was undertaken to investigate of effects of additive containing probiotic Protexin (100 g/ton), vitamin C (300mg/ kg), and betaine (1kg/ton) in three commercial broiler strains on growth performance under heat stress condition. This study was conducted in 2×3 factorial arrangement consisting 2 levels of additive (with and without) and three strains (Arbor Acres, Cobb 500, and Ross 308) with 6 treatments, 4 replicates and 30 birds in each replicate. Birds were reared under thermoneutral conditions (23 °C) until day 21. Then they exposed to heat stress (37 °C) 8 hours/day from day 21 to 42. Multiple attribute decision making method was used to select best strain and decision about using this additive under heat stress. Based on scoring by this method, Ross 308, Cobb 500, and Arbor Acres obtained these scores respectively: 0.8587, 0.7595 and 0.6884. Arbor Acres, Cobb 500, and Ross 308 chicks not received additive, respectively showed poorest performance under heat stress. Based on the results, additive containing probiotic, vitamin C, and betaine can be advised as a solution to alleviate negative effect of heat stress on performance of commercial broiler strains