Bashir Ghasempour; Abolghasem Golian; Ahmad hassanabadi
Volume 19, Issue 3 , November 2017, , Pages 711-726
Abstract
This experiment was conducted to evaluate the effect of varying levels of digestible protein (DP) and dietary electrolyte balances (DEB) during the finisher period on performance, blood parameters and small intestine histology of broiler chickens exposed to heat stress. A total of 500 mixed sex chickens ...
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This experiment was conducted to evaluate the effect of varying levels of digestible protein (DP) and dietary electrolyte balances (DEB) during the finisher period on performance, blood parameters and small intestine histology of broiler chickens exposed to heat stress. A total of 500 mixed sex chickens (Ross 308) were used in a completely randomized design as a 2×5 factorial arrangement with two levels of DP (%16.5 and %19) and five levels of DEB (150, 200, 250, 300 and 350 meq/kg of diet)with five replicates of 10 birds each during the finisher period. The chicks were exposed to heat stress of 32±2 °C for eight hours/day during 28-42 days of age. Increasing DP levels did not have a significant effect on weight gain under heat stress during the finisher period. Feed intake and feed conversion ratio (FCR) of chickens fed 16.5% DP diet was significantly more than 19% DP fed birds (P<0.05). The highest weight gain and lowest FCR were observed in chickens fed 200 mEq/kg of diet EBD which were significantly different only with 300 and 150 mEq/kg EBD treatments. The highest weight gain was observed in broilers fed diet containing 16.5% DP and 200 mEq EBD. Broilers fed diet containing 19% DP in compare to those fed 16.5% DP had lower plasma triglycerides and higher total protein, creatinine, and uric acid contents. Increasing digestible protein from 16.5% to 19% had no significant effect (P>0.05) on small intestine morphology. Diet containing 250 mEq/kg of diet EBD significantly (P<0.05) increased villi surface of small intestine in chickens suffering heat stress. It is concluded that, feeding of broiler chickens exposed to heat stress during the finishing period with diet containing 16.5% digestible protein and 200 mEq/kg dietary electrolyte balances is recommendable.