1 材料与方法
1.1 试验材料
表1 芦竹叶和苜蓿干草常规营养成分(干物质基础)Table 1 Conventional nutrients of giant reed leaves and alfalfa hay (DM basis) % |
| 项目 Items | 芦竹叶 Giant reed leaves | 苜蓿干草 Alfalfa hay |
|---|---|---|
| 总能GE/(MJ/kg) | 18.73 | 19.73 |
| 粗蛋白质CP | 25.06 | 27.33 |
| 粗脂肪EE | 2.90 | 2.69 |
| 中性洗涤纤维NDF | 63.22 | 33.02 |
| 酸性洗涤纤维ADF | 26.33 | 21.94 |
| 淀粉Starch | 1.76 | 3.53 |
| 粗灰分Ash | 10.83 | 8.50 |
1.2 试验设计
1.2.1 发酵底物
表2 各组发酵底物原料组成及营养水平(干物质基础)Table 2 Composition and nutrient levels of fermentation substrate in each group (DM basis) % |
| 项目 Items | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 原料Ingredients | |||||||||||
| 芦竹叶Giant reed leaves | 5.0 | 10.0 | 15.0 | 20.0 | |||||||
| 苜蓿干草Alfalfa hay | 20.0 | 15.0 | 10.0 | 5.0 | |||||||
| 麦秸Wheat straw | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | ||||||
| 青贮玉米Corn silage | 28.8 | 28.8 | 28.8 | 28.8 | 28.8 | ||||||
| 豆粕Soybean meal | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | ||||||
| 玉米Corn | 18.0 | 18.0 | 18.0 | 18.0 | 18.0 | ||||||
| 麸皮Wheat bran | 4.2 | 4.2 | 4.2 | 4.2 | 4.2 | ||||||
| 甜菜粕Beet meal | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | ||||||
| 啤酒糟Brewer’s grains | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | ||||||
| 酱香型白酒糟Moutai-flavor liquor distiller’s grains | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | ||||||
| 食盐NaCl | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | ||||||
| 磷酸氢钙CaHPO4 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | ||||||
| 预混料Premix1) | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | ||||||
| 合计Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | ||||||
| 营养水平Nutrient levels2) | |||||||||||
| 泌乳净能NEL/(MJ/kg) | 6.09 | 5.96 | 5.83 | 5.70 | 5.57 | ||||||
| 代谢能ME/(MJ/kg) | 10.42 | 10.21 | 10.00 | 9.79 | 9.58 | ||||||
| 粗蛋白质CP | 14.81 | 14.69 | 14.58 | 14.47 | 14.35 | ||||||
| 中性洗涤纤维NDF | 43.15 | 44.66 | 46.17 | 47.68 | 49.10 | ||||||
| 酸性洗涤纤维ADF | 23.68 | 23.98 | 24.27 | 24.57 | 24.86 | ||||||
| 钙Ca | 0.77 | 0.75 | 0.72 | 0.69 | 0.66 | ||||||
| 磷P | 0.54 | 0.53 | 0.52 | 0.52 | 0.51 |
1)每千克预混料含有 One kilogram of premix contained the following:Ca 210 000~395 000 mg,P≥21 000 mg,VA 151 000~227 000 IU,VD3 26 500~49 500 IU,VE≥1 250 mg,硝酸硫铵 ammonium sulfate nitrate≥16.0 mg,烟酰胺 niacinamide≥60.0 mg,叶酸 folic acid≥48.0 mg,D-生物素 D-biotin≥1.00 mg,氯化胆碱 choline chloride≥192 mg,Fe 510~18 000 mg,Cu 195~365 mg,Zn 1 280~2 400 mg,Mn 1 070~2 950 mg,Se 5.60~10.5 mg。 2)泌乳净能和代谢能参考NY/T 34—2004计算,其他为实测值。NEL and ME were calculated referred to NY/T 34—2004, while the others were measured values. |
1.2.2 瘤胃液采集
1.2.3 瘤胃缓冲液配制
表3 瘤胃缓冲液单一溶液组成Table 3 Single solution composition of rumen buffer |
| 项目Items | 组成Composition |
|---|---|
| 微量元素溶液 Trace element solution (A) | CaCl2·2H2O 13.20 g,CoCl2·6H2O 1.00 g,MnCl2·4H2O 10.00 g, FeCl3·6H2O 8.00 g,加蒸馏水定容至100.00 mL |
| 缓冲液 Buffer solution (B) | NH4HCO3 4.00 g,NaHCO3 35.00 g, 加蒸馏水定容至1 000.00 mL |
| 常量元素溶液 Constant element solution (C) | Na2HPO4·12H2O 9.45 g,KH2PO4 6.20 g,MgSO4·7H2O 0.60 g,加蒸馏水定容至1 000.00 mL |
| 刃天青溶液Resazurin solution (D) | 刃天青0.10 g,加蒸馏水定容至100.00 mL |
| 还原剂溶液 Reducing agent solution (E) | NaOH 0.16 g,Na2S·9H2O 0.625 g, 加蒸馏水定容至100.00 mL |
E液需先配制1 mol/L的氢氧化钠溶液,后进行溶液配制;B液和E液需现用现配。 | |
Liquid E needs to be prepared with 1 mol/L sodium hydroxide solution first, and then the solution is prepared. Liquid B and liquid E need to be used on the spot. |
1.2.4 试验操作
1.3 样品采集及指标测定
1.3.1 样品采集
1.3.2 常规营养成分含量测定
1.3.3 产气参数测定
1.3.4 发酵底物养分降解率测定
1.3.5 发酵参数测定
1.3.6 瘤胃菌群结构分析
1.4 数据统计与分析
2 结果与分析
2.1 芦竹叶替代苜蓿干草对瘤胃体外发酵特性的影响
2.1.1 芦竹叶替代苜蓿干草对瘤胃体外发酵产气参数和养分降解率的影响
表4 芦竹叶替代苜蓿干草对瘤胃体外发酵产气参数和养分降解率的影响Table 4 Effects of giant reed leaves replacing alfalfa hay on gas production parameters and nutrient degradation rates of rumen fermentation in vitro |
| 项目 Items | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 累积产气量Cumulative gas production/mL | |||||||
| 3 h | 13.88abc | 12.01c | 13.13bc | 15.24ab | 16.76a | 0.57 | 0.035 |
| 6 h | 18.26d | 34.09a | 28.62b | 26.19bc | 23.28c | 1.47 | <0.001 |
| 9 h | 30.98 | 38.01 | 34.21 | 32.12 | 29.40 | 1.63 | 0.560 |
| 12 h | 44.34 | 38.85 | 39.37 | 37.02 | 46.41 | 1.81 | 0.472 |
| 24 h | 60.29 | 54.66 | 52.83 | 68.87 | 66.05 | 2.33 | 0.100 |
| 理论最大产气量 Theoretical maximum gas production/mL | 67.00bc | 56.97c | 54.35c | 85.28a | 78.61ab | 3.61 | 0.002 |
| 产气速率Gas generation rate/(mL/h) | 3.69 | 5.09 | 3.46 | 3.05 | 3.23 | 0.35 | 0.424 |
| 产气迟滞时间Gas production lag time/h | 0.001 | -1.075 | -1.516 | -2.557 | -1.409 | 0.599 | 0.812 |
| 干物质降解率DMD/% | 61.07 | 60.15 | 63.74 | 57.84 | 55.92 | 1.02 | 0.112 |
| 有机物降解率OMD/% | 83.87 | 77.63 | 75.60 | 93.39 | 90.26 | 2.58 | 0.100 |
同行数据肩标无字母或相同字母表示无显著差异(P>0.05),不同小写字母表示差异显著(P<0.05)。下表同。 | |
In the same row, values with no letter or the same letter superscripts mean no significant difference (P>0.05), while with different small letter superscripts mean significant difference (P<0.05). The same as below. |
2.1.2 芦竹叶替代苜蓿干草对瘤胃体外发酵参数的影响
2.1.2.1 芦竹叶替代苜蓿干草对瘤胃体外发酵NH3-N含量的影响
表5 芦竹叶替代苜蓿干草对瘤胃体外发酵NH3-N含量的影响Table 5 Effects of giant reed leaves replacing alfalfa hay on NH3-N content of rumen fermentation in vitro mg/dL |
| 时间 Time/h | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 3 | 12.26 | 11.56 | 12.12 | 11.88 | 10.81 | 0.20 | 0.136 |
| 6 | 10.32 | 10.32 | 10.71 | 10.21 | 9.52 | 0.26 | 0.744 |
| 9 | 11.42 | 11.91 | 12.10 | 11.84 | 11.17 | 0.28 | 0.871 |
| 12 | 13.55 | 12.04 | 11.20 | 10.83 | 11.84 | 0.39 | 0.204 |
| 24 | 14.80c | 14.62c | 15.92bc | 21.38a | 20.41ab | 0.96 | 0.025 |
2.1.2.2 芦竹叶替代苜蓿干草对瘤胃体外发酵MCP含量的影响
表6 芦竹叶替代苜蓿干草对瘤胃体外发酵MCP含量的影响Table 6 Effects of giant reed leaves replacing alfalfa hay on MCP content of rumen fermentation in vitro mg/dL |
| 时间 Time/h | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 3 | 1.55 | 1.66 | 1.56 | 1.95 | 2.42 | 0.15 | 0.295 |
| 6 | 0.94 | 0.92 | 0.98 | 1.11 | 1.00 | 0.04 | 0.570 |
| 9 | 1.30 | 1.34 | 1.55 | 1.47 | 1.39 | 0.04 | 0.205 |
| 12 | 0.95 | 0.87 | 0.99 | 1.00 | 0.88 | 0.04 | 0.764 |
| 24 | 1.40a | 1.31ab | 1.29abc | 1.20bc | 1.12c | 0.03 | 0.029 |
2.1.2.3 芦竹叶替代苜蓿干草对瘤胃体外发酵pH的影响
表7 芦竹叶替代苜蓿干草对瘤胃体外发酵pH的影响Table 7 Effects of giant reed leaves replacing alfalfa hay on pH of rumen fermentation in vitro |
| 时间 Time/h | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 3 | 6.91 | 6.94 | 6.91 | 6.92 | 6.92 | 0.01 | 0.981 |
| 6 | 6.91c | 6.85d | 6.91c | 6.99b | 7.04a | 0.02 | <0.001 |
| 9 | 6.87 | 6.89 | 6.87 | 6.92 | 6.98 | 0.02 | 0.090 |
| 12 | 6.87 | 6.90 | 6.93 | 6.96 | 6.92 | 0.02 | 0.467 |
| 24 | 6.86c | 6.92bc | 6.94b | 6.96ab | 7.03a | 0.02 | 0.006 |
2.1.2.4 芦竹叶替代苜蓿干草对瘤胃体外发酵24 h VFA含量的影响
表8 芦竹叶替代苜蓿干草对瘤胃体外发酵24 h VFA含量的影响Table 8 Effects of giant reed leaves replacing alfalfa hay on VFA content at 24 h of rumen fermentation in vitro |
| 项目 Items | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 总挥发性脂肪酸TVFA/(mg/mL) | 3.896b | 3.783b | 3.856b | 4.292a | 4.253a | 0.071 | 0.022 |
| 乙酸Acetic acid/(mg/mL) | 2.062bc | 2.000c | 2.038c | 2.321a | 2.286ab | 0.046 | 0.033 |
| 丙酸Propionic acid/(mg/mL) | 0.877 | 0.869 | 0.878 | 0.920 | 0.897 | 0.007 | 0.072 |
| 丁酸Butyric acid/(mg/mL) | 0.637b | 0.618b | 0.629b | 0.700a | 0.721a | 0.013 | 0.005 |
| 戊酸Valeric acid/(mg/mL) | 0.119 | 0.112 | 0.114 | 0.126 | 0.126 | 0.002 | 0.086 |
| 异丁酸Isobutyric acid/(mg/mL) | 0.058 | 0.055 | 0.062 | 0.064 | 0.064 | 0.001 | 0.115 |
| 异戊酸Isovaleric acid/(mg/mL) | 0.143ab | 0.129b | 0.136b | 0.162a | 0.161a | 0.004 | 0.031 |
| 乙酸/丙酸Acetic acid/propionic acid | 2.350bc | 2.303c | 2.323bc | 2.518ab | 2.549a | 0.036 | 0.042 |
2.2 芦竹叶替代苜蓿干草对瘤胃体外发酵菌群结构的影响
2.2.1 alpha多样性分析
表9 芦竹叶替代苜蓿干草对瘤胃体外发酵菌群alpha多样性的影响Table 9 Effects of giant reed leaves replacing alfalfa hay on alpha diversity of microbiota of rumen fermentation in vitro |
| 项目 Items | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| Observed_species指数 Observed_species index | 1 032.67 | 1 073.67 | 1 046.67 | 1 174.00 | 1 146.00 | 21.64 | 0.136 |
| Chao1指数Chao1 index | 1 111.99 | 1 139.68 | 1 104.45 | 1 221.22 | 1 214.53 | 19.81 | 0.157 |
| Shannon指数Shannon index | 6.79 | 6.80 | 6.66 | 7.21 | 6.63 | 0.09 | 0.318 |
| Simpson指数Simpson index | 0.960 | 0.963 | 0.958 | 0.968 | 0.942 | 0.004 | 0.345 |
2.2.2 beta多样性分析
2.2.3 物种组成分析
表10 芦竹叶替代苜蓿干草瘤胃体外发酵菌群相对丰度的影响Table 10 Effects of giant reed leaves replacing alfalfa hay on relative abundance of microbiota of rumen fermentation in vitro % |
| 项目 Items | 对照组 Control group | 25%组 25% group | 50%组 50% group | 75%组 75% group | 100%组 100% group | 均值 标准误 SEM | P值 P-value |
|---|---|---|---|---|---|---|---|
| 门水平Phylum level | |||||||
| 厚壁菌门Firmicutes | 51.38 | 45.16 | 50.27 | 48.42 | 55.94 | 1.52 | 0.248 |
| 拟杆菌门Bacteroidota | 31.56 | 31.78 | 31.75 | 34.62 | 30.66 | 0.76 | 0.603 |
| 变形菌门Proteobacteria | 9.74bc | 16.56a | 12.00ab | 7.00bc | 4.79c | 1.32 | 0.014 |
| 疣微菌门Verrucomicrobiota | 2.28 | 1.07 | 1.14 | 2.16 | 1.92 | 0.21 | 0.220 |
| 髌骨菌门Patescibacteria | 1.29 | 1.36 | 1.14 | 2.03 | 1.45 | 0.12 | 0.177 |
| 广古菌门Euryarchaeota | 0.70 | 1.08 | 0.88 | 1.91 | 1.60 | 0.17 | 0.128 |
| 脱硫杆菌门Desulfobacterota | 0.78bc | 0.55c | 0.69bc | 1.12ab | 1.24a | 0.09 | 0.023 |
| 属水平Genus level | |||||||
| 普雷沃氏菌属Prevotella | 13.06 | 14.40 | 13.93 | 13.84 | 11.76 | 0.48 | 0.503 |
| 赖氨酸芽孢杆菌属Lysinibacillus | 14.37 | 10.52 | 14.95 | 8.93 | 12.88 | 1.04 | 0.327 |
| 理研菌科RC9肠道群 Rikenellaceae_RC9_gut_group | 10.46 | 9.09 | 9.81 | 11.15 | 10.67 | 0.29 | 0.166 |
| 芽孢杆菌属Bacillus | 11.50 | 6.92 | 7.56 | 7.01 | 5.30 | 1.25 | 0.670 |
| 库特氏菌属Kurthia | 3.05 | 7.31 | 3.91 | 7.29 | 14.59 | 1.92 | 0.380 |
| 土壤芽孢杆菌属Solibacillus | 4.48 | 3.82 | 6.50 | 2.70 | 3.13 | 0.47 | 0.051 |
| 解琥珀酸菌属Succiniclasticum | 2.77 | 2.24 | 2.31 | 3.47 | 3.35 | 0.25 | 0.408 |
| 不动杆菌属Acinetobacter | 2.54ab | 4.83a | 3.09ab | 1.39b | 0.94b | 0.47 | 0.037 |
| 丛毛单胞菌属Comamonas | 1.22 | 4.50 | 3.07 | 0.97 | 0.40 | 0.54 | 0.052 |
| 丁酸弧菌属Butyrivibrio | 1.45 | 1.47 | 1.61 | 1.72 | 1.72 | 0.06 | 0.384 |
