Effect of Astragalus Membranaceus Straw on Cattle Rumen Digestion In Vitro
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摘要:
目的 采用人工瘤胃法研究黄芪茎叶粉对肉牛体外瘤胃发酵参数、产气量及干物质消化率的影响,以期为黄芪茎叶粉在反刍动物生产中的应用提供理论参考。 方法 试验分为玉米秸秆对照组(CON组)和黄芪组(AM组)两个处理,每组3个重复,分别于发酵的不同时间点(0、1、2、3、4、5、6、7、8、10、12、14、16、20、24、28、32、36、40、44、48、56、64、72 h)记录两组的产气量,并在发酵72 h后终止发酵,测定发酵液的pH、氨态氮、挥发性脂肪酸和干物质消化率的变化。 结果 1)黄芪茎叶粉极显著降低了瘤胃发酵各时间点的产气量和理论最大产气量,但提高了发酵的产气速率(P<0.01);2)黄芪茎叶粉显著提高了瘤胃挥发性脂肪酸中乙酸的含量和乙酸/丙酸比值(P<0.01),降低了氨态氮、总挥发性脂肪酸、丙酸和丁酸含量(P<0.05);3)黄芪茎叶粉对瘤胃pH和干物质消化率没有显著影响(P>0.05)。 结论 黄芪茎叶粉降低了瘤胃总产气量,对于促进瘤胃乙酸型发酵具有一定调控作用,具有作为反刍动物饲料和饲料添加剂应用的潜力。 Abstract:Objective Effect of Astragalus membranaceus straw on in vitro rumen digestion of cattle was investigated to determine the applicability of Astragalus membranaceus straw in ruminant feed. Methods An experiment was divided into two groups of corn stalk meal (CON group) and Astragalus membranaceus straw meal (AM group) with three repeats per group. Gas production in the in vitro fermentation at 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 36, 40, 44, 48, 56, 64, and 72 h were monitored. At 72 h, the terminal pH and contents of ammonia nitrogen, volatile fatty acids, and dry matters digestibility were measured. Results (1) In AM group, the amounts of gas production at all sampling points during the fermentation were significantly reduced but the gas production rate was increased (P<0.01). (2) In AM group, the acetic acid content and the acetic acid to propionic acid ratio were significantly higher (P<0.01), but the contents of ammonia nitrogen, total volatile fatty acid, propionic acid and butyric acid were lowered significantly (P<0.05). (3) No significant differences on pH and dry matter digestibility were observed between CON and AM (P>0.05). Conclusion Astragalus membranaceus straw decreased the total rumen gas production, and had a certain regulatory effect on rumen acetic acid fermentation, which indicated Astragalus membranaceus straw had the potential to be used as feed and feed additive for ruminants. -
Key words:
- Astragalus membranaceus /
- rumen /
- gas production /
- fermentation parameters /
- dry matter digestibility
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表 1 玉米秸秆和黄芪茎叶粉中主要营养成分
Table 1. Main nutrients in corn stalk and AM (单位:%)
指标Items 玉米秸秆Corn stalk 黄芪茎叶粉Astragalus membranaceus straw 干物质Dry matter 85.8 86.5 粗蛋白Crude protein 5.9 10.9 粗脂肪Ether extract 1.3 1.5 粗纤维Crude fiber 35.0 30.2 粗灰分Crude ash 7.0 3.0 无氮浸出物Nitrogen free extract 36.6 40.8 钙Calcium 0.35 1.43 磷Phosphorus 0.19 0.10 表 2 黄芪茎叶粉对产气量模型参数的影响
Table 2. Effects of AM on parameters of gas production model
指标Items 对照组CON group 黄芪组AM group 12 h产气量 Gas production in 12 hours / mL 28.07±1.65 A 19.07±1.35 B 24 h产气量Gas production in 24 hours / mL 33.17±1.65 A 20.17±1.35 B 48 h产气量Gas production in 48 hours / mL 31.90±2.00 A 19.63±1.65 B 72 h产气量Gas production in 72 hours / mL 33.80±4.30 A 20.53±2.35 B 理论最大产气量B Theoretical maximum gas production/ mL 32.84±2.05 A 20.16±1.98 B 产气速率cGas generation rate/(mL·h−1) 0.16±0.01 b 0.21±0.02 a 表中同行数据后不同大、小写字母表示处理之间差异极显著(P<0.01)或显著(P<0.05),相同字母或无字母表示差异不显著(P>0.05)。下同。In the table, different capital shoulder letters in the table indicate significant differences between groups (P<0.01), different lowercase letters showed significant difference (P<0.05), the same letter or no shoulder letters indicates no significant difference (P> 0.05), the same as below. 表 3 黄芪茎叶粉对瘤胃发酵液pH、氨态氮和干物质消化率的影响
Table 3. Effects of AM on rumen pH, ammonia nitrogen, and dry matter digestibility in vitro
指标Items 对照组CON group 黄芪组AM group pH 6.90±0.10 7.02±0.01 氨态氮Ammonia Nitrogen / (mg·dL−1) 21.70±1.23 a 14.20±4.24 b 干物质消化率Dry matter digestibility/% 63.88±6.46 58.00±0.82 表 4 黄芪茎叶粉对体外瘤胃挥发性脂肪酸的影响
Table 4. Effects of AM on rumen volatile fatty acids in vitro
指标Item 对照组CON group 黄芪组AM group 总挥发酸Total volatile acid/(mmol·L−1) 28.33±0.74 a 15.83±0.35 b 乙酸 Acetate/% 65.03±0.40 B 69.63±0.30 A 丙酸 Propionic acid/% 19.17±0.10 A 17.70±0.17 B 丁酸 Butyrate/% 12.30±0.20 A 9.10±0.06 B 戊酸 Valerate/% 0.90±0.25 0.77±0.06 异丁酸 Isobutyrate/% 0.87±0.56 1.07±0.10 异戊酸 Isovalerate/% 1.80±0.06 1.80±0.06 乙酸/丙酸The ratio of acetate acid to propionic acid 3.43±5.35 B 3.93±5.47 A -
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