Department of Animal Science, Rasht Branch, Islamic Azad University, Rasht, Iran.
Department of Biological Sciences and Chemistry, College of Arts and Sciences, University of Nizwa, Birkat Al-Mouz, Nizwa, Oman.
Vet Med Sci. 2022 Nov;8(6):2511-2520. doi: 10.1002/vms3.923. Epub 2022 Sep 1.
Coccidiosis is an endemic protozoal disease of chickens normally controlled by ionophores. However, coccidiostats are also antibiotics, and evidence of resistance in both coccidia and bacteria may develop and reduce antibacterial activity in humans. This has led to a search for natural coccidiostats, such as green tea.
To study the effects of supplementing broilers with various levels and types of green tea, in comparison to use of a conventional coccidiostat or a control, unsupplemented diet.
A total of 360 male, day-old Ross 308 broilers (days 1-42) were used to evaluate the gut morphology and performance when challenged with coccidiosis and fed varying dietary levels of green tea powder or extract. Treatments were Negative control (NC, unsupplemented control diet); positive control (PC, control diet + commercial coccidiostat); control diets with 0.2, 0.3 or 0.4 g/kg green tea extract (GTE 0.2, 0.3 and 0.4); and control diets with 1, 2 or 3 g/kg green tea powder (GTP 1, 2 and 3).
Compared with NC, PC and all green tea treatments, but particularly GTE0.4, increased feed intake and growth rate, with the best feed conversion ratio at GTE0.4. As a proportion of carcase weight, higher inclusion rates increased intestine weight and decreased abdominal fat. The duodenum, jejunum and ileum of birds fed green tea, and particularly GTE0.4, had longer, wider villi, and shallower crypts. Epithelium thickness was reduced by green tea and PC, compared to NC. Clostridium perfringens and coliform populations decreased in proportion to green tea inclusion rate and decreased in PC. Lactobacilli increased with green tea and were more for NC than PC. Green tea at the highest concentrations reduced blood glucose and LDL and VLDL cholesterol.
Green tea offers a possible replacement for conventional ionophores to control coccidiosis in broiler chickens. The best inclusion rate was 0.4 g/kg.
球虫病是一种地方性的鸡原虫病，通常通过离子载体来控制。然而，球虫抑制剂也是抗生素，在球虫和细菌中都可能出现耐药性，并降低人类的抗菌活性。这导致人们寻找天然的球虫抑制剂，如绿茶。
研究在感染球虫的情况下，给肉鸡补充不同水平和类型的绿茶，与使用常规球虫抑制剂或未补充的对照饮食相比，对其肠道形态和性能的影响。
使用 360 只雄性，1 日龄罗斯 308 肉鸡（1-42 日龄），评估在感染球虫时，不同水平的绿茶粉或提取物对肠道形态和性能的影响。处理组为阴性对照组（NC，未补充对照饮食）；阳性对照组（PC，对照饮食+商业球虫抑制剂）；含 0.2、0.3 或 0.4 g/kg 绿茶提取物的对照饮食（GTE 0.2、0.3 和 0.4）；含 1、2 或 3 g/kg 绿茶粉的对照饮食（GTP 1、2 和 3）。
与 NC、PC 和所有绿茶处理组相比，尤其是 GTE0.4 组，饲料摄入量和生长速度增加，GTE0.4 组的饲料转化率最佳。与体重比相比，更高的添加量增加了肠道重量，减少了腹部脂肪。与 NC 相比，饲喂绿茶的鸡，尤其是 GTE0.4，其十二指肠、空肠和回肠的绒毛更长、更宽，隐窝更浅。与 NC 相比，绿茶和 PC 降低了上皮细胞厚度。随着绿茶的添加，梭状芽孢杆菌和大肠菌群的比例降低，PC 组则降低。与 NC 相比，绿茶组的乳酸菌数量增加。绿茶在最高浓度时降低了血糖和 LDL 和 VLDL 胆固醇。
绿茶为控制肉鸡球虫病提供了一种替代常规离子载体的可能。最佳添加量为 0.4 g/kg。
