Energy Type and Amount in the Diets of Broiler Chickens: Effects on Performance and Duodenal Morphology

The present study was conducted to investigate the effects of dietary energy sources and levels on performance and small intestinal morphology in broiler chickens. A total of 600 one-day-old broiler chicks were randomly divided into five treatments with four replicates each. Chicks were fed diet based on corn as main energy source and energy level based on Cobb 500 manual instruction considered control group (C), basal diet with 3% lesser energy than control (T1), basal diet with 6% lesser energy than control (T2), basal diet based on corn and soy oil level according to Cobb 500 manual instruction (T3), basal diet based on corn and soy oil with 3% upper energy (T4) for 42 days. Results showed that chicks in T3 group had higher body weight, body weight gain and duodenum villus height compared to control group (C) and improved feed conversion ratio (FCR) at day 42 of age (P<0.05). Chicks in T2 group exhibited the lowest body weight (BW), body weight gain (BWG) and FCR but the highest feed intake (P<0.05). Feeding of diet T4 improved daily weight gain and duodenal villus height while caused concurrently increased FCR. Energy levels greater than Cobb recommendation significantly increased the villus height of the duodenum and decreased crypt depth compared to the control group (P<0.05). In order to achieve a higher weight more energy is needed than the recommended manual instruction for Cobb 500 but to have better feed conversion ratio the energy level recommended manual instruction is sufficient.