Ruminants are considered a major producer of methane (CH₄). Therefore, the present study aimed to determine the ability of dry fennel seeds to affect in vitro gas production and fermentation. Fennel seeds were included at 0% (Control), 0.5%, 1%, 1.5%, and 2% DM of a diet containing per kg DM: 500 g concentrate feed mixture, 400 g berseem hay, and 100 g of rice straw. The incubations lasted 48 h. Fennel seeds increased (P < 0.001) the asymptotic gas production and decreased its rate, while decreasing the production and proportion of CH₄ (P < 0.05) and increased its rate. Moreover, fennel seed increased DM and neutral detergent fiber (P < 0.01) degradability, and increased total production of short-chain fatty acids, acetate, and propionate (P < 0.05). Compared to the control, fennel seeds increased (P < 0.01) metabolizable energy, partitioning factor, and microbial crude protein production. Overall, fennel seeds can be included up to 2% DM in ruminant diets as an environmentally friendly product in animal farming due to its ability to improve feed utilization, ruminal fermentation and while reducing CH₄ production.

中文翻译：

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茴香籽膳食纳入作为减少甲烷产生、改善养分利用率和瘤胃发酵的可持续方法

_{反刍动物被认为是甲烷 (CH 4} )的主要产生者。因此，本研究旨在确定干茴香籽影响体外气体产生和发酵的能力。茴香籽的含量为 0%（对照）、0.5%、1%、1.5% 和 2% DM，每公斤 DM 含有：500 g 浓缩饲料混合物、400 g berseem 干草和 100 g 稻草。孵育持续48小时。茴香籽增加了渐近产气量（P < 0.001），降低了渐进产气率；同时降低了CH ₄ 的产量和比例（P  < 0.05），提高了渐近产气率。此外，茴香籽还提高了DM和中性洗涤纤维的降解性（P  <0.01），并增加了短链脂肪酸、乙酸盐和丙酸盐的总产量（P  <0.05）。与对照相比，茴香籽增加了（P  <0.01）代谢能、分配因子和微生物粗蛋白产量。总体而言，茴香籽可在反刍动物日粮中添加高达 2% 的干物质，作为动物养殖中的环保产品，因为它能够提高饲料利用率、瘤胃发酵并同时减少 CH _{4 的}产生。