Ruminant Nutrition and Emissions, Agroscope, 1725 Posieux and 8356 Ettenhausen, Switzerland; ETH Zurich, Institute of Agricultural Sciences, 8315 Lindau, Switzerland.
Ruminant Nutrition and Emissions, Agroscope, 1725 Posieux and 8356 Ettenhausen, Switzerland.
J Dairy Sci. 2023 Oct;106(10):6816-6833. doi: 10.3168/jds.2022-22901. Epub 2023 Jul 26.
This study investigated the effects of acacia (extract of Acacia mearnsii) and sainfoin (Onobrychis viciifolia) as condensed tannin (CT)-rich sources on ruminal and manure methane (CH) emissions in comparison with non-CT silages characterized by different contents of the cell wall and water-soluble carbohydrates. In a 3 × 6 incomplete Latin square design, 30 Holstein cows (63 ± 23 d in milk; mean ± SD; 33.8 ± 7.6 kg of milk per day, body weight 642 ± 81 kg) were provided with ad libitum access to 1 of 6 total mixed rations comprising 790 g of silage and 210 g of concentrate per kilogram of dry matter (DM). The silages were either rich in sainfoin [neutral detergent fiber (NDF): 349 g/kg of DM], perennial ryegrass (NDF: 420 g/kg of DM), or red clover (NDF: 357 g/kg of DM). Each silage was supplemented with 20 g/kg (of total diet DM) of acacia or straw meal. Feed intake and milk yield were recorded daily. Milk composition and ruminal fluid characteristics and microbiota were analyzed. The individual ruminal CH production was determined using the GreenFeed system, and CH emissions from the manure of cows fed the same diets were measured in a parallel experiment over 30 d at 25°C using a dynamic flux chamber. The CT sources did not reduce CH yield or emission intensity. Acacia reduced milk production (from 26.3 to 23.2 kg/d) and DM intake (from 19.7 to 16.7 kg/d) when supplemented with ryegrass, and both CT sources reduced the milk protein content and yield. Acacia supplementation and ryegrass silage reduced the ruminal acetate:propionate ratio. Furthermore, during acacia treatment, the abundance of Methanobrevibacter archaea tended to be lower and that of Thermoplasmata was higher. Acacia reduced the CH emissions from manure for the ryegrass group by 17% but not for the sainfoin and clover groups. Feeding sainfoin silage resulted in the lowest manure-derived CH emissions (-47% compared with ryegrass). In conclusion, acacia reduced ruminal CH production by 10%, but not emission intensity, and the mitigation effect of sainfoin depended on the silage to which it was compared. Because mitigation was partially associated with animal productivity losses, careful evaluation is required before the implementation of tanniferous feeds in farm practice.
本研究以非单宁青贮为对照，比较了金合欢（Acacia mearnsii）和苦马豆（Onobrychis viciifolia）作为富含单宁（CT）的来源对瘤胃和粪便甲烷（CH）排放的影响，这些非单宁青贮具有不同的细胞壁和水溶性碳水化合物含量。采用 3×6 不完全拉丁方设计，30 头荷斯坦奶牛（泌乳期 63±23 天；平均±标准差；33.8±7.6 kg/d，体重 642±81 kg）自由采食 6 种全混合日粮中的 1 种，每种日粮包含 790 g 青贮料和 210 g 精料/kg 干物质（DM）。青贮料分别富含苦马豆（中性洗涤纤维（NDF）：349 g/kg DM）、多年生黑麦草（NDF：420 g/kg DM）或红三叶草（NDF：357 g/kg DM）。每一种青贮料都添加了 20 g/kg（日粮 DM 总量）的金合欢或麦秸粉。每日记录采食量和产奶量。分析牛奶成分、瘤胃液特性和微生物区系。使用 GreenFeed 系统测定个体瘤胃 CH 产量，在 25°C 下使用动态通量室平行试验测定饲喂相同日粮的奶牛粪便中 CH 的排放，持续 30 d。CT 源并没有降低 CH 的产量或排放强度。金合欢与黑麦草青贮料一起添加时，降低了产奶量（从 26.3 降至 23.2 kg/d）和 DM 采食量（从 19.7 降至 16.7 kg/d），两种 CT 源均降低了牛奶蛋白含量和产量。金合欢的添加和黑麦草青贮降低了瘤胃乙酸：丙酸比。此外，在金合欢处理期间，甲烷古菌的丰度趋于降低，而 Thermoplasmata 的丰度升高。金合欢减少了黑麦草组粪便中的 CH 排放，减少了 17%，但对苦马豆和三叶草组没有影响。与黑麦草相比，饲喂苦马豆青贮料导致粪便中 CH 排放量最低（-47%）。综上所述，金合欢降低了瘤胃 CH 产量 10%，但没有降低排放强度，而苦马豆的缓解效果取决于与其比较的青贮料。由于缓解效果部分与动物生产性能损失有关，因此在农场实践中实施单宁饲料之前，需要进行仔细评估。
