Effect of a multicarbohydrase supplementation to diets varying in metabolisable energy level on the performance, carcase traits, caecal microbiota, intestinal morphology, and nutrient digestibility in broiler chickens

Abstract

This trial was conducted to investigate the effects of multi-carbohydrase supplementation on the performance, carcase traits, intestinal histomorphology, caecal microbiota and nutrient digestibility of broiler chickens fed diets with varying energy levels. A total of 400-day-old male chicks were allocated into eight dietary treatments in a 4 × 2 factorial arrangement with 5 replicates per treatment. There were 4 dietary energy levels (the standard breed recommendation and reductions of 50, 100 and 150 kcal/kg from the standard) with or without multi-carbohydrase supplementation. Reducing the energy level by 50 kcal/kg did not significantly impact the measured parameters compared to the standard recommendation while it is reducing by 100 and 150 kcal/kg resulted in significant decreases in the body weight (BW) by levels up to 4.41% and a significant increase in the feed conversion ratio (FCR) by levels up to 4.67%. Enzyme supplementation significantly improved the BW and FCR by 3.24% and 2.95%, respectively. Dietary energy lowered by 100–150 kcal/kg resulted in a significant decrease in the dressing (up to 2.42%), breast yield (up to 2.82%), fat pads (up to 8.72%), liver (up to 6.30%) percentages and coliform count (up to 28.5%). The digestibility of dry matter, crude protein, ether extract and gross energy was increased due to enzyme supplementation by 4.15, 3.50, 3.35 and 3.72%, respectively. In conclusion, broiler performance and carcase traits can be negatively impacted if the energy density is reduced by 100–150 kcal/kg diet. Enzyme supplementation can improve the performance and nutrient digestibility regardless of the dietary energy level.HIGHLIGHTS The metabolisable energy level can be reduced by 50 kcal/kg diets compared to the breed recommendation. Decreasing the energy level by 100 or 150 kcal/kg diet compared to breed recommendations resulted in a negative impact on the performance. Multicarbohydrase blend supplementation resulted in significant improvements in the performance and nutrient digestibility.