Artemisia Annua as Phytogenic Feed Additive in the Diet of Broilers (14-35 Days) Reared under Heat Stress (32 ºC)

ABSTRACT The 21 days feeding trial was conducted on 90, Cobb 500 broilers (aged 14 days), assigned to 3 groups (C, E1 and E2) housed in an experimental hall at 32° C constant temperature and 23 h light regimen. During the growth period (14-35 days), the conventional diet (C) had corn and soybean meal as basic ingredients. Unlike the conventional diet formulation (C), the diet formulations for the experimental groups also included 0.005% Artemisia annua oil (E1) and 0.005% Artemisia annua oil plus 1% Artemisia annua powder (E2). Six broilers per group were slaughtered at 35 days of age in order to measure the weight of the carcass and internal organs of broilers, and samples of intestinal and caecal content were collected for bacteriological assessment (Enterobacteriaceae, E. coli, staphylococci, Lactobacilli, Salmonella spp.).The following parameters were monitored during the experimental period: bodyweight (g); average daily feed intake (g feed/broiler/day); average daily weight gain (g/broiler/day); feed conversion ratio (g feed/g gain). Under heat stress (32 ºC), E2 broilers (mixture of A. annua oil and powder) had a significantly (p<0.05) higher average of daily feed intake than the broilers receiving the C diet or the diet supplemented just with A. annua oil (E1). Both samples of intestinal and caecal content, showed the lowest count (p<0.05) of Enterobacteriaceae, E. coli and staphylococcus colony forming units in E2 broilers. Diet with A. annua oil and powder provided proper conditions for lactic acid bacteria proliferation in the intestine and caecum of heat stressed broilers.

摘要 本试验选取90只14日龄科宝500（Cobb 500）肉鸡，分为3组（C、E1、E2），于恒温32℃、光照时长23小时的试验舍内开展为期21天的饲喂试验，试验周期覆盖14~35日龄。对照组日粮（C）以玉米与豆粕为基础原料；试验组日粮在基础日粮基础上分别添加0.005%青蒿油（Artemisia annua oil，E1组），以及0.005%青蒿油与1%青蒿粉（Artemisia annua powder，E2组）。于35日龄时每组屠宰6只肉鸡，测定其屠体与内脏器官重量，并采集肠道及盲肠内容物进行细菌学检测，检测指标涵盖肠杆菌科（Enterobacteriaceae）、大肠杆菌（E. coli）、葡萄球菌（staphylococci）、乳杆菌（Lactobacilli）及沙门氏菌属（Salmonella spp.）。试验期间监测的指标包括：体重（g）、平均日采食量（g/只·天）、平均日增重（g/只·天）及料重比（g饲料/g增重）。在32℃热应激条件下，E2组（青蒿油与青蒿粉复配组）的平均日采食量显著高于C组及仅添加青蒿油的E1组（p<0.05）。肠道与盲肠内容物样本检测结果显示，E2组的肠杆菌科、大肠杆菌及葡萄球菌菌落形成单位数均显著最低（p<0.05）。添加青蒿油与青蒿粉的日粮可为热应激肉鸡的肠道及盲肠内乳酸菌增殖提供适宜条件。