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.

摘要

进行该试验的目的是研究补充多种糖化酶对饲喂不同能量水平日粮的肉鸡的生产性能，case体性状，肠道组织形态，盲肠微生物群和营养消化率的影响。将总共​​400天的雄性小鸡以4×2因子分配方式分配到八种饮食处理中，每种处理重复5次。饮食中有4种饮食能量水平（建议标准品种，与标准饮食相比分别降低50、100和150 kcal / kg）。与标准建议相比，将能量水平降低50 kcal / kg不会显着影响测量的参数，而将能量水平降低100和150 kcal / kg则可导致体重（BW）显着降低4级。41％的饲料转化率（FCR）显着提高，最高可达4.67％。补充酶能分别将BW和FCR分别提高3.24％和2.95％。饮食能量降低100–150 kcal / kg，导致敷​​料（最多2.42％），乳房增产（最多2.82％），脂肪垫（最多8.72％），肝脏（最多6.30％）显着下降。百分比和大肠菌群计数（高达28.5％）。通过添加酶，干物质，粗蛋白，醚提取物和总能量的消化率分别提高了4.15％，3.50％，3.35％和3.72％。总之，如果能量密度降低100–150 kcal / kg饮食，对肉鸡的生产性能和car体性状可能会产生负面影响。无论膳食能量水平如何，补充酶均可改善性能和营养物质的消化率。

• 强调

• 与品种推荐相比，日粮可代谢能量降低50 kcal / kg。

• 与品种推荐相比，将能量水平降低100或150 kcal / kg饮食对性能产生负面影响。

• 多糖合酶混合物的添加显着改善了性能和养分消化率。