文献类型： 外文期刊

第一作者： Zhang, Lin

作者： Zhang, Lin;Huan, Hailin;Zhang, Kai;Tu, Yuanlu;Yan, Junshu;Xi, Yumeng;Zhang, Hao

作者机构：

关键词： beta-mannanase; broilers; energy; intestinal microbial communities; performance

期刊名称：JOURNAL OF ANIMAL SCIENCE （ 影响因子：2.9； 五年影响因子：3.3 ）

ISSN： 0021-8812

年卷期： 2024 年 102 卷

页码：

收录情况： SCI

摘要： This study assessed the effects of beta-mannanase (BM) supplementation on growth performance, digestive enzyme activity, cecal microbial communities, and short-chain fatty acid (SCFA) production in broiler chickens fed diets with different metabolizable energy (ME) levels. A total of 1,296 male 1-d-old Cobb 500 broilers were randomly distributed in a 3 x 2 factorial arrangement (3 ME levels x 0 or 200 g/ton BM), with 6 replicates per treatment combination. The 3 ME levels were 3,000 (ME1), 2,930 (ME2), and 2,860 (ME3) kcal/kg, respectively, during the 0 to 3 wk-old stages and 3,150 (ME1), 3,080 (ME2), and 3,010 (ME3) kcal/kg, respectively, during the 3 to 6 wk-old stages. Reducing ME levels increased broiler feed intake (P = 0.036) and decreased average daily gain (ADG, P = 0.002) during the entire period. While BM supplementation increased ADG (P = 0.002) and improved the feed conversion ratio (P = 0.001) during the 0 to 3 wk-old stages, with no effect during the 3 to 6 wk-old stages. Overall, reducing ME levels increased pancreatic lipase (P = 0.045) and amylase (P = 0.013) activity and duodenal amylase activity (P = 0.047). Notably, BM supplementation significantly increased pancreatic lipase activity (P = 0.015) and increased lipase (P = 0.029) and amylase (P = 0.025) activities in the jejunal chyme. Although diet or enzyme supplementation did not affect microbial diversity, significant differences in microbial communities were observed. At the genus level, decreasing ME levels significantly affected the average abundances of Tyzzerella (P = 0.028), Candidatus_Bacilloplasma (P = 0.001), Vibrio (P = 0.005), and Anaerotruncus (P = 0.026) among groups, whereas BM supplementation reduced the average abundances of Escherichia-Shigella (P = 0.048) and increased the average abundances of Barnesiella (P = 0.047), Ruminococcus (P = 0.020), Alistipes (P = 0.050), and Lachnospiraceae_unclassified (P = 0.009). SCFA concentrations strongly depended on bacterial community composition, and BM supplementation increased acetic acid (P = 0.004), propionic acid (P = 0.016), and total SCFA concentrations. In conclusion, BM supplementation improved the performance of younger broilers, and both enzyme supplementation and reduced ME levels positively affected digestive enzyme activity and intestinal microflora. This study found that BM-supplemented diets are effective in improving performance, digestive enzyme activity, and intestinal flora in broilers fed low-ME or normal-ME diets. These results may help achieve higher economic productivity of broiler farms. The broiler industry currently faces numerous challenges, especially the significant rise in feedstuff prices, and the economic considerations with regard to feedstuff formulation have become important factors for reducing costs and enhancing benefits. Low-energy diets have been increasingly suggested to control feed costs; however, lower nutrient concentrations may result in reduced performance, thereby increasing attention toward the potential use of feed enzymes. In this study, we have assessed the impacts of beta-Mannanase (BM), the major beta-mannan degrading enzyme, supplementation on poultry health and digestion. Our study involved a total of 1,296 Cobb broilers, randomly distributed into a 3 x 2 factorial arrangement to evaluate the effects of BM supplementation on growth, digestive enzyme activity, cecal microbial communities, and SCFA production in broiler chickens fed diets with varying ME levels. Our findings confirmed previous research by showing that BM-supplemented diets are effective in improving performance in younger broilers. In addition, we found that both BM supplementation and reduced ME levels also have positive impacts on digestive enzyme activity and intestinal flora in chickens, which might account for improving production performance. These results will be a crucial refence for the scientific implementation of BM supplementation, which may help achieve better performance and intestinal microecology, resulting in higher economic productivity of broiler farms.

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