1 材料与方法
1.1 试验材料
表1 杂交狼尾草化学特性与微生物组成Table 1 Chemical characteristics and microbial composition of hybrid Pennisetum |
| 项目Items | 含量Content |
|---|---|
| 干物质DM/(g/kg FM) | 181.33 |
| pH | 6.22 |
| 水溶性碳水化合物WSC/(g/kg DM) | 96.35 |
| 粗蛋白质CP/(g/kg DM) | 143.00 |
| 中性洗涤纤维NDF/(g/kg DM) | 635.00 |
| 酸性洗涤纤维ADF/(g/kg DM) | 343.00 |
| 乳酸菌LAB/[lg(CFU/g FM)] | 6.24 |
| 酵母菌Yeast/[lg(CFU/g FM)] | 6.27 |
| 好氧菌AB/[lg(CFU/g FM)] | 6.42 |
FM:鲜物质 fresh matter;DM:干物质 dry matter。 |
1.2 试验设计
1.3 指标测定
1.3.1 原料特性和青贮品质
1.3.2 有氧暴露后发酵指标和微生物数量
1.3.3 综合价值评价
1.3.4 微生物多样性
1.4 数据统计分析
2 结果与分析
2.1 不同浓度丙酸对杂交狼尾草青贮营养品质的影响
表2 不同丙酸浓度对杂交狼尾草青贮营养品质的影响Table 2 Effects of different concentrations of propionic acid on nutritional quality of hybrid Pennisetum silage g/kg DM |
| 组别 Groups | 干物质 DM | 粗蛋白质 CP | 可溶性碳水化合物 WSC | 中性洗涤纤维 NDF | 酸性洗涤纤维 ADF |
|---|---|---|---|---|---|
| CK | 207.00±1.50d | 82.52±5.11c | 13.66±1.02c | 570.48±13.09a | 342.61±2.25a |
| T1 | 220.50±0.70c | 98.21±5.05b | 9.47±0.70d | 492.53±25.71b | 290.55±19.85b |
| T2 | 239.50±2.10a | 122.96±7.18a | 23.81±0.29b | 521.85±12.21b | 300.57±1.60b |
| T3 | 226.00±0.10b | 124.12±4.98a | 28.46±1.07a | 593.47±15.61a | 368.06±21.98a |
2.2 不同浓度丙酸对杂交狼尾草青贮发酵品质的影响
表3 不同丙酸浓度对杂交狼尾草青贮发酵品质的影响Table 3 Effects of different concentrations of propionic acid on fermentation quality of hybrid Pennisetum silage |
| 组别 Groups | pH | 乳酸 LA/(g/kg DM) | 乙酸 AA/(g/kg DM) | 丙酸 PA/(g/kg DM) | 丁酸 BA/(g/kg DM) | 氨态氮/总氮 NH3-N/TN/% |
|---|---|---|---|---|---|---|
| CK | 4.30±0.03b | 8.64±0.13cd | 0.17±0.02b | 2.17±0.04b | 0.50±0.02a | 42.63±3.27b |
| T1 | 4.34±0.02a | 10.01±0.22c | 0.30±0.03a | 1.75±0.03c | 0.28±0.01b | 50.02±2.77a |
| T2 | 3.49±0.01d | 17.18±0.53a | 0.01±0.00c | 2.60±0.07a | 0.03±0.01c | 7.14±0.49c |
| T3 | 3.55±0.01c | 13.38±0.47b | 0.02±0.00c | 1.77±0.01c | 0.02±0.01c | 6.85±0.29c |
2.3 不同浓度丙酸对杂交狼尾草青贮有氧暴露后发酵指标和微生物数量的影响
2.3.1 有氧暴露后发酵指标
表4 不同浓度丙酸对杂交狼尾草青贮有氧暴露后发酵指标的影响Table 4 Effects of different concentrations of propionic acid on fermentation indexes of hybrid Pennisetum silage after aerobic exposure |
| 项目 Items | 组别 Groups | 有氧暴露时间Aerobic exposure time/d | 标准误 SE | P值P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 3 | 6 | 9 | 丙酸浓度 Propionic acid concentration | 有氧暴露时间 Aerobic exposure time | 丙酸浓度× 有氧暴露时间 Propionic acid concentration× aerobic exposure time | ||||
| CK | 4.30±0.03Ca | 5.12±0.00Cb | 7.14±0.00Bb | 7.75±0.00Aa | 1.43 | <0.001 | <0.001 | <0.001 | ||
| pH | T1 | 4.32±0.00Da | 5.93±0.00Ca | 7.77±0.00Aa | 7.57±0.00Bb | |||||
| T2 | 3.48±0.00Dc | 3.91±0.00Bd | 3.86±0.00Cd | 4.67±0.00Ad | ||||||
| T3 | 3.54±0.00Db | 4.45±0.00Bc | 3.95±0.00Cc | 6.20±0.00Ac | ||||||
| CK | 8.64±0.13Ad | 8.44±0.03Bd | 0.76±0.04Cc | 0.18±0.04Dc | 5.16 | <0.001 | <0.001 | <0.001 | ||
| 乳酸 | T1 | 10.01±0.22Ac | 8.84±0.25Bc | 0.37±0.08Cd | 0.31±0.08Cb | |||||
| LA/(g/kg DM) | T2 | 17.18±0.53Aa | 9.73±0.10Ba | 5.45±0.13Cb | 1.59±0.11Da | |||||
| T3 | 13.38±0.46Ab | 9.14±0.25Bb | 6.17±0.21Ca | 0.33±0.02Db | ||||||
| CK | 9.74±0.35Ca | 18.60±0.18Aa | 11.21±0.11Ba | 5.29±0.03Da | 4.99 | <0.001 | <0.001 | <0.001 | ||
| 氨态氮 | T1 | 7.84±0.28ABb | 7.70±0.14Bb | 8.06±0.03Ab | 4.35±0.06Cb | |||||
| NH3-N/(g/kg DM) | T2 | 1.41±0.18Ac | 1.57±0.01Ac | 1.02±0.07Bc | 0.39±0.03Cd | |||||
| T3 | 1.36±0.06Bd | 1.63±0.02Ac | 1.12±0.23Cc | 0.81±0.01Dc | ||||||
同行数据肩标不同大写字母表示不同有氧暴露时间之间差异显著(P<0.05),同列数据肩标不同小写字母表示不同组别之间差异显著(P<0.05)。 | |
Values in the same row with different capital letter superscripts mean significant difference in different aerobic exposure times (P<0.05), and values in the same column with different small letter superscripts mean significant difference in different groups (P<0.05). |
2.3.2 微生物数量
图1 不同浓度丙酸对杂交狼尾草青贮有氧暴露后微生物数量的影响数据柱形标注不同小写字母表示不同组别之间差异显著(P<0.05),不同大写字母表示不同有氧暴露时间之间差异显著(P<0.05)。 Fig.1 Effects of different concentrations of propionic acid on microbial number of hybrid Pennisetum silage after aerobic exposure Value columns with different small letter superscripts mean significant difference in different groups (P<0.05), and with different capital letter superscripts mean significant difference in different aerobic exposure times (P<0.05). |
2.4 综合价值评价和排序
表5 综合价值评价和排序Table 5 Comprehensive value evaluation and rank |
| 项目 Items | 组别Groups | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| CK | T1 | T2 | T3 | ||||||
| 青贮60 d Silage 60 d | |||||||||
| 干物质DM | 0.00 | 0.42 | 1.00 | 0.58 | |||||
| 粗蛋白质CP | 0.00 | 0.38 | 0.97 | 1.00 | |||||
| 可溶性碳水化合物WSC | 0.22 | 0.00 | 0.76 | 1.00 | |||||
| 中性洗涤纤维NDF | 0.23 | 1.00 | 0.71 | 0.00 | |||||
| 酸性洗涤纤维ADF | 0.33 | 1.00 | 0.87 | 0.00 | |||||
| pH | 0.05 | 0.00 | 1.00 | 0.93 | |||||
| 乳酸LA | 0.00 | 0.16 | 1.00 | 0.56 | |||||
| 乙酸AA | 0.55 | 1.00 | 0.00 | 0.03 | |||||
| 丙酸PA | 0.49 | 0.00 | 1.00 | 0.02 | |||||
| 丁酸BA | 0.00 | 0.46 | 0.98 | 1.00 | |||||
| 氨态氮/总氮NH3-N/TN | 0.17 | 0.00 | 0.99 | 1.00 | |||||
| 有氧暴露9 d Aerobic exposure 9 d | |||||||||
| pH | 0.00 | 0.06 | 1.00 | 0.50 | |||||
| 乳酸LA | 0.00 | 0.09 | 1.00 | 0.11 | |||||
| 氨态氮NH3-N | 0.00 | 0.19 | 1.00 | 0.91 | |||||
| 乳酸菌LAB | 0.90 | 1.00 | 0.23 | 0.00 | |||||
| 酵母菌Yeast | 0.00 | 0.12 | 1.00 | 0.99 | |||||
| 好氧菌AB | 0.00 | 0.11 | 1.00 | 0.86 | |||||
| 综合价值评定值Comprehensive value evaluation value | 0.17 | 0.35 | 0.85 | 0.56 | |||||
| 排序Rank | 4 | 3 | 1 | 2 | |||||
2.5 丙酸对杂交狼尾草青贮微生物多样性的影响
图2 微生物OTU韦恩图韦恩图中不同颜色的圈表示不同分组,图中的数字分别代表了每个分组共有或特有的OTU数目。CK:对照组;PA:适宜浓度丙酸组。 Fig.2 Microbial OTU Venn diagram The colored circles in Venn diagram represented different groups, and the numbers in the diagram represented the number of OTU that common or unique in each group. CK: control group; PA: appropriate concentration propionic acid group. |
2.5.1 Alpha多样性分析
表6 Alpha多样性指数分析Table 6 Alpha diversity index anaiysis |
| 项目 Items | 组别Groups | P值 P-value | |
|---|---|---|---|
| CK | PA | ||
| ACE指数ACE index | 210.17±14.17 | 226.37±11.14 | 0.19 |
| Chao1指数Chao1 index | 206.83±24.78 | 228.33±4.95 | 0.22 |
| Shannon指数Shannon index | 1.68±0.10 | 1.54±0.08 | 0.13 |
| Simpson指数Simpson index | 0.37±0.03 | 0.37±0.03 | 0.89 |
| 覆盖度Coverage | 1.00±0.00 | 1.00±0.00 | 0.15 |
2.5.2 基于门水平的微生物群落结构分析
图3 杂交狼尾草青贮门水平的细菌相对丰度Unclassified bacteria:未分类的细菌;Chloroflexi:绿弯菌门;Bdellovibrionota:蛭弧菌门;Deinococcota:脱氨基可卡因菌门;Patescibacteria:髌骨细菌门;Bacteroidota:拟杆菌门;Actinobacteriota:放线菌门;Cyanobacteria:蓝藻菌门;Proteobacteria:变形菌门;Firmicutes:厚壁菌门;Others:其他。 Fig.3 Relative abundance of bacteria at phylum level of hybrid Pennisetum silage |
2.5.3 基于属水平的微生物群落结构分析
图4 杂交狼尾草青贮属水平的细菌相对丰度Arthrobacter:节杆菌属;Microbacterium:微杆菌属;Norank_f_Mitochondria:未被定义线粒体;Pantoea:泛菌属;Lactococcus:乳球菌属;Enterobacter:肠杆菌属;Delftia:代尔夫特菌属;Norank_f_norank_o_Chloroplast:未被定义叶绿体;Weissella:魏斯氏菌属;Lactobacillus:乳杆菌属;Others:其他。 Fig.4 Relative abundance of bacteria at genus level of hybrid Pennisetum silage |

京公网安备 11010802041926号