This study was carried out to evaluate the effect of essential oils or saponins alone or in combination on productive performance, intestinal morphology, and digestive enzymes' activity in broilers. Four hundred one‐day‐old male broiler chickens were randomly assigned to four treatments, each with 5 replicates. The birds were fed experimental diets contained either no phytogenic feed additives (control) or were supplemented with 25.0 mg/kg of an essential oil blend from star anise, rosemary, thyme and oregano (essential oils); 46.0 mg/kg of a Quillaja saponin blend (saponins); or a combination of both phytogenic preparations (essential oils plus saponins). The experiment lasted for 42 days. Body weight, feed intake and weight gain were recorded weekly, and the feed conversion ratio was calculated, throughout the experiment. Intestinal morphology and digestive enzymes' activity were determined at the end of the experiment. It was found that the body weight was increased by all dietary supplements at the end of the experiment. There was no change in performance parameters among the treatments during the starter period. At the grower period and the overall experiment, the weight gain of birds was higher in all supplemented groups compared to the control, but the feed conversion was better in the essential oils with saponins treatment. Supplementation of essential oils or saponins alone or in combination increased the villus height and the villus/crypt ratio of the intestine. There was an increase in trypsin, chymotrypsin and elastase activities in the essential oils plus saponins group only. The obtained results indicate that the phytogenic feed additives, especially essential oils with saponins, can be considered as new promising agents in promoting the growth performance of broilers. The effect could be related to its improving impact in intestinal development and increasing the protease enzymes' activity, resulting in increased protein digestibility and absorption of dietary nutrients.

中文翻译：

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精油或皂苷单独或联合使用对肉鸡生产性能、肠道形态和消化酶活性的影响。

本研究旨在评估精油或皂苷单独或联合使用对肉鸡生产性能、肠道形态和消化酶活性的影响。400 只 1 日龄雄性肉鸡被随机分配到 4 个处理，每个处理 5 个重复。给这些鸟喂食不含植物源性饲料添加剂（对照）或添加了 25.0 mg/kg 来自八角茴香、迷迭香、百里香和牛至（精油）的精油混合物的实验日粮；46.0 mg/kg 的 Quillaja 皂苷混合物（皂苷）；或两种植物制剂的组合（精油加皂苷）。实验持续了42天。在整个实验过程中，每周记录体重、采食量和增重，并计算饲料转化率。在实验结束时测定肠道形态和消化酶的活性。发现在实验结束时，所有膳食补充剂都增加了体重。在开始期间，处理之间的性能参数没有变化。在生长期和整个实验中，与对照组相比，所有添加组的鸟类体重增加均更高，但添加皂苷处理的精油的饲料转化率更好。单独或组合补充精油或皂苷可增加肠道的绒毛高度和绒毛/隐窝比率。仅在精油加皂苷组中胰蛋白酶、胰凝乳蛋白酶和弹性蛋白酶活性增加。所得结果表明，植物性饲料添加剂，尤其是含皂苷的精油，可被认为是促进肉鸡生长性能的新剂。这种作用可能与其改善肠道发育的影响和增加蛋白酶的活性有关，从而增加蛋白质的消化率和膳食营养素的吸收。