Background: Supplementing broiler diets with non-starch polysaccharide multi-enzymes (NME) has been shown to improve nutrient utilization and performance. However, the interaction between dietary soybean oil levels and NME supplementation in wheat-based diets requires further exploration. Objectives: The aim of the present study was to evaluate the dietary soya bean oil level and NME supplementation in a low energy wheat-based diet effects on performance, bone mechanical properties and mineral contents, blood metabolites, small intestine morphology and immunity criteria in the broiler chickens. Methods: A total of 360 one-day-old mixed-sex Ross308 broiler chicks were randomly assigned to 6 treatments, five replicates/treatment and 12 (6 females and 6 meals) birds/replicate. Experimental treatments were included factorial arrangement 0, 6 and 12% levels of diet metabolizable energy supplied by soy oil of (MESO) with/ without NME supplementation. For starter (1-10 d), grower (11-24 d) and finisher (25-38 d) rearing periods, six isocaloric and isonitrogenous experimental diets were formulated and fed ad-libitum. Results: There was not significant difference in growth performance traits between birds fed diets with different levels of MESO during starter period. As well as increased dietary MESO levels; weight gain and feed conversion ratio during grower, finisher and whole rearing periods linearly improved. Also, abdominal fat relative weight, breast meat cooking lost and jejunum muscular thickness linearly increased and liver relative weight and jejunum crypt depth linearly decreased. Dietary NME supplementation led to improve production performance during the starter, grower and whole experimental periods, enhanced tibia bone strength and abdominal fat, and decreased gizzard and intestine relative weight and decreased jejunum muscular thickness. Conclusions: It was concluded, dietary NME supplementation and supply 12% of broiler chickens metabolizable energy requirement through soy oil has a positive effect on growth performance, bone strength, liver and small intestine health of broiler chickens fed low energy wheat-based diet.

Keywords