Stevia, a perennial shrub from the genus Stevia in the Asteraceae family, contains active ingredients like chlorogenic acid and shows promise as a natural feed additive. Despite this potential, there is limited research on the impact of stevia extract specifically on yellow-feather broilers. The study aimed to evaluate the effects of dietary stevia extract with varying concentrations of chlorogenic acid on the growth performance, serum biochemical indices, and intestinal health of yellow-feathered broilers. A total of 425 1-d-old female yellow-feathered broilers were randomly allocated into five treatment groups with five replicates of 17 broilers each, and the feeding trial lasted 63 d. The groups included control and those supplemented with stevia extract at concentrations of 100, 200, 300, and 400 mg/kg. Results showed that adding 100 mg/kg of stevia extract to the basal diet significantly increased the daily weight gain (ADG) of the broilers while reducing the average daily feed intake and feed conversion ratio (F/G). However, supplementation with stevia extract at concentrations up to 300 mg/kg led to decreased final weight and ADG. Conversely, dietary supplementation with 100-200 mg/kg of stevia extract improved serum antioxidant capacity and reduced serum total cholesterol levels compared to the control group. Additionally, the cecum n-butyric acid level was significantly higher in the 200 mg/kg stevia extract group than in the control group. In conclusion, supplementing yellow-feathered broilers’ diets with stevia extract can enhance growth performance, antioxidant and immune capacity, and intestinal health. The optimal concentration of stevia extract for these benefits is between 100 and 200 mg/kg.

中文翻译：

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日粮甜叶菊提取物补充剂对黄羽肉鸡生长性能、血清生化指标和肠道健康的影响


甜叶菊是菊科甜叶菊属的多年生灌木，含有绿原酸等活性成分，有望成为天然饲料添加剂。尽管有这种潜力，但关于甜叶菊提取物对黄羽肉鸡影响的研究有限。本研究旨在评价不同浓度绿原酸的日粮甜叶菊提取物对黄羽肉鸡生长性能、血清生化指标和肠道健康的影响。将 425 只 1 d 龄雌性黄羽肉鸡随机分为 5 个处理组，每个处理组 5 个重复，每个 17 只肉鸡，饲喂试验持续 63 d。这些组包括对照组和补充浓度为 100、200、300 和 400 mg/kg 的甜叶菊提取物的组。结果表明，在基础日粮中添加 100 mg/kg 甜叶菊提取物可显著提高肉鸡的日增重 （ADG），同时降低平均日采食量和饲料转化率 （F/G）。然而，补充浓度高达 300 mg/kg 的甜叶菊提取物导致最终重量和 ADG 降低。相反，与对照组相比，膳食中添加 100-200 mg/kg 甜叶菊提取物可提高血清抗氧化能力并降低血清总胆固醇水平。此外，200 mg/kg 甜叶菊提取物组的盲肠正丁酸水平显著高于对照组。总之，在黄羽肉鸡的日粮中补充甜叶菊提取物可以提高生长性能、抗氧化和免疫能力以及肠道健康。具有这些益处的甜叶菊提取物的最佳浓度在 100 至 200 mg/kg 之间。