Study Reactive Effects of Lighting Systems and Addition Melatonin and L - Tryptophane on Heat Shock Proteins (HSP70), Melatonin and The Antioxidant Status in Broiler Chicken Managed in Hot Climates

Abstract

The study examined how lighting system, feed additive, or their synergy reduces the negative effects of hot climates on broiler chicks in Iraq. Two light programs were tested. CLP is the first program, with 23 hours of light and one hour of scotoperiod. The second program, Intermittent Lighting Program (ILP), consisted of 9 hours’ photoperiod, 3 hours scotoperiod, and 4 nutritive treatments. T1 (Control). T2 adds 0.50 mg/kg/ration melatonin. T3 adds 400 mg/kg/ration tryptophane. T4 adds 400 mg/kg tryptophane and cofactors. 240 one-day-old male Ross 308 chicks with a mean body weight of 47 gm were managed until day 7 of the experiment. Three replicates of 10 chicks were randomly assigned to 8 treatments. The experiment lasted 49 days. ILP improved (P < 0.05) in heat shock proteins. HSP70 vs. CLP T2, T3, and T4 improved significantly from T1. ILP also benefits from feed additive interaction. The interaction between feed additive and lighting program showed that T2 in CLP and T3 in ILP improved significantly (P < 0.05) compared to T1, T3, and T4 of CLP and T1 and T2 of ILP, but not T4. In conclusion, intermittent lighting with or without nutritional additives mitigated the negative effects of hot climates on broilers’ antioxidant status and HSP70 levels.