Responses of Broiler Chickens Fed Low or High Non-Starch Polysaccharide Diets and the Addition of Humic Substances from a Worm Compost

ABSTRACT The objective was to evaluate the productivity, microbiology and histopathology of the jejunum, ceca and liver in broilers fed a control or a high non-starch polysaccharide (HNSPs) diet added with an extract of humic substances (EHS). 240 broilers individually allocated, from 21-42 d of age were assigned to a factorial arrangement of 2 types of diets: 1) A corn/soybean meal diet (Control) and 2) As Control plus 7% distillers dried grain with solubles and 12% of wheat bran (HNSPs), and 3 growth promoters: 1) Antibiotic growth promoters (AGP); 2) without AGP (NAGP) and C) with 0.5% of EHS. At the end of the trial, the breast and carcass were weighed and samples of the intestine, ceca and liver were taken for microbial and histopathology analysis. Results were subjected to ANOVA. EHS-fed broilers had lower feed conversion ratio (FCR) and total aerobic bacterial (TAB) counts in the liver and higher ashes digestibility with the Control diet, but negative responses were seen with the HNSPs diet (Type of diet and growth promoter interaction, p≤0.05). The lesion scores in the jejunum were lower in EHS-fed broilers with the Control and HNSPs diet (p≤0.05). The TAB and E. coli were lower in the jejunum and ceca of AGP-fed broilers (p<0.01) compared to NAGP and EHS groups. EHS-fed broilers showed improved FCR and ileal ashes digestibility and lower TAB in the liver with the Control diet and had lower lesion score in the jejunum and similar weight gain compared to the AGP-fed broilers.

摘要 本研究旨在评估饲喂基础日粮或添加腐殖物质提取物（extract of humic substances, EHS）的高非淀粉多糖（high non-starch polysaccharide, HNSPs）日粮的肉仔鸡空肠、盲肠和肝脏的生产性能、微生物学指标及组织病理学变化。试验选取240只肉仔鸡，于21~42日龄进行单笼饲养，采用2×3析因设计分组：2种日粮类型分别为1）玉米-豆粕基础日粮（对照组）；2）基础日粮添加7%可溶性干酒糟及其可溶物与12%麦麸（高非淀粉多糖组，HNSPs）；3种生长促进剂分别为1）抗生素生长促进剂（Antibiotic growth promoters, AGP）；2）无抗生素生长促进剂（without AGP, NAGP）；3）添加0.5%腐殖物质提取物（EHS）。试验结束后，称量胸肌与屠体重量，并采集肠道、盲肠及肝脏样本用于微生物学与组织病理学分析。试验数据采用方差分析（ANOVA）进行统计处理。饲喂腐殖物质提取物（EHS）的肉仔鸡在基础日粮组中表现出更低的饲料转化率（feed conversion ratio, FCR）、肝脏需氧菌总数（total aerobic bacterial, TAB）及更高的灰分消化率，但在高非淀粉多糖（HNSPs）日粮组中则呈现负面响应（日粮类型与生长促进剂存在交互作用，p≤0.05）。饲喂基础日粮或高非淀粉多糖（HNSPs）日粮且添加EHS的肉仔鸡，其空肠病变评分更低（p≤0.05）。与NAGP组及EHS组相比，饲喂AGP的肉仔鸡空肠与盲肠中的需氧菌总数（TAB）及大肠杆菌（E. coli）数量均显著降低（p<0.01）。饲喂EHS的肉仔鸡在基础日粮组中，饲料转化率（FCR）与回肠灰分消化率得到改善，肝脏需氧菌总数（TAB）更低，且空肠病变评分更低，其增重与饲喂AGP的肉仔鸡无显著差异。