Chinese Journal of Animal Nutrition >

2023 , Vol. 35 >Issue 6: 3856 - 3866

DOI: https://doi.org/10.12418/CJAN2023.358

RESEARCH PAPER

Effects of Different Enzyme Preparation Combinations on Silage Quality and in Vitro Rumen Fermentation Characteristics of Rice Straw

  • ZHOU Miaoyu , 1 ,
  • WU Weicheng 1 ,
  • XIAO Dingfu , 1, ** ,
  • CHEN Dong , 1, ** ,
  • JIANG Runyao 1 ,
  • ZENG Yuanyuan 1 ,
  • WEI Zhongshan 2 ,
  • PENG Fanchang 3 ,
  • LI Fuqiang 3
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  • 1 College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
  • 2 Hunan Dren Grass Technology Development Co., Ltd., Changde 415000, China
  • 3 Hunan Tianhua Industrial Co., Ltd., Loudi 417000, China
**XIAO Dingfu, professor; E-mail: ;
CHEN Dong, associate professor, E-mail:

*Contributed equally

Received date: 2022-11-23

  Online published: 2023-06-08

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Abstract

This experiment was designed to investigate the effects of different enzyme preparation combinations on silage quality and in vitro rumen fermentation characteristics of rice straw. The experiment used rice straw as silage material, and added different enzyme preparation combinations, four groups were established: control group (CK group, no enzyme preparation added), C group (added 1.0 g/kg cellulase, xylanase and β-glucanase compound enzyme preparation), PL group (added 0.5 g/kg pectinase+1.0 g/kg laccase) and CPL group (added 1.0 g/kg cellulase, xylanase and β-glucanase compound enzyme preparation+0.5 g/kg pectinase+1.0 g/kg laccase), with five replicates in each group. Samples were opened after 60 days of silage, and the silage quality and in vitro rumen fermentation characteristics were analyzed. The results showed as follows: 1) the rice straw after silage, the dry matter content of PL group was significantly higher than that of CK, C and CPL groups (P<0.05); the ether extract, relative feed value and total digestible nutrients of CPL group were significantly higher than those of CK group (P<0.05), and the neutral detergent fiber and acid detergent fiber contents were significantly lower than those of CK group (P<0.05). 2) After 24 h of in vitro fermentation, the 24 h cumulative gas production, gas production in the slow degradation fraction and potential gas production of C, PL and CPL groups were significantly higher than those of CK group (P<0.05), and the gas production in the fast fraction was significantly lower than that of CK group (P<0.05); the gas production rate in the slow degradation fraction of PL and CPL groups was significantly higher than that of CK and C groups (P<0.05). 3) The pH of C, PL and CPL groups was significantly lower than that of CK group (P<0.05), and the ammonia nitrogen content of CPL was significantly higher than that of C and CK groups (P<0.05). 4) The dry matter degradation rate of C, PL and CPL groups was significantly higher than that of CK group (P<0.05), the crude protein degradation rate of CPL group was significantly higher than that of CK group (P<0.05), and the neutral detergent fiber degradation rate of CPL group was significantly higher than that of CK and PL groups (P<0.05). In summary, the addition of different enzyme preparation combinations can improve the silage quality of rice straw and in vitro rumen fermentation characteristics to some extent, and in production practice, it is recommended to add a combination of cellulase, xylanase and β-glucanase compound enzyme preparation+pectinase+laccase, which is beneficial to obtain better quality of rice straw silage feed.

Key words： rice straw; enzyme preparation; in vitro rumen fermentation

Cite this article

ZHOU Miaoyu , WU Weicheng , XIAO Dingfu , CHEN Dong , JIANG Runyao , ZENG Yuanyuan , WEI Zhongshan , PENG Fanchang , LI Fuqiang . Effects of Different Enzyme Preparation Combinations on Silage Quality and in Vitro Rumen Fermentation Characteristics of Rice Straw[J]. Chinese Journal of Animal Nutrition, 2023 , 35(6) : 3856 -3866 . DOI: 10.12418/CJAN2023.358

秸秆作为草食性家畜重要的粗饲料来源之一,其利用价值具有一定优势[1]。对秸秆进行再回收利用,作为粗饲料饲喂反刍动物,发挥其营养价值,不仅可以缓解我国草食动物饲料资源日益紧缺的现状,而且有助于国家节粮型畜牧业的发展[2]。由于秸秆纤维素含量较高,纤维素主要由葡萄糖单元聚合而成,微纤维之间的氢键作用较强[3],从而造成水稻秸秆饲料化利用率低,有将近1/5的水稻秸秆被焚烧或丢弃,造成饲料资源的浪费,对环境也会产生一定的污染[4]。反刍动物直接饲喂水稻秸秆效果不佳,适口性差,利用率低,而且会降低反刍动物的采食量。因此,如何提高水稻秸秆的营养价值,为反刍动物提供优质的粗饲料,是当前水稻秸秆饲料资源浪费亟需解决的一大问题。
目前,越来越多的养殖户将粗饲料通过青贮的方式来有效保存养分,以达到全年均衡供给饲草的目的[5]。将水稻秸秆进行青贮可以提高饲料利用率,延长饲料保存时间,提高饲料适口性,增加反刍动物采食量。但常规青贮后的水稻秸秆仍达不到预期的青贮效果,部分研究尝试使用青贮添加剂来改善青贮发酵品质,比如纤维素酶、漆酶等[5⇓-7]都是较常用的青贮添加剂。木聚糖酶属于半纤维素酶的一种,它能够破损植物细胞壁,提高体外营养物质消化率[8]。β-葡聚糖酶由纤维素酶分泌产生,能够降解植物细胞壁碳水化合物[9]。纤维素酶能够促进粗饲料青贮发酵,提高可溶性碳水化合物(WSC)含量,使得青贮饲料中的pH和酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、氨态氮(NH3-N)含量下降,从而提高青贮饲料品质[10⇓-12]。漆酶具有多种催化功能,可加速秸秆分解,提高木质纤维素的降解效率,是环保且多功能的生物催化剂[13⇓-15]。Wang等[16]研究表明,果胶酶有助于青贮饲料的发酵,能够改变青贮发酵特性,提高发酵品质。大多数试验采用纤维素酶和乳酸菌或二者组合来提高青贮品质,对其他酶制剂的相关研究较少。因此,本试验尝试添加其他酶制剂来提高青贮品质,研究在常见复合酶制剂的基础上添加果胶酶和漆酶是否同样能够提高水稻秸秆的青贮品质,达到改善发酵品质的目的,通过添加不同酶制剂组合来提高水稻秸秆的青贮品质,以期寻找理想的酶制剂组合,为合理利用水稻秸秆资源提供科学依据。

1 材料与方法

1.1 青贮试验

1.1.1 试验材料

青贮原料采用湖南农业大学耘园基地种植的湘早优45号水稻秸秆,完熟期刈割并切碎2~3 cm保存备用,留茬高度10 cm。水稻秸秆的营养物质含量[干物质(DM)基础]为:DM 35.28%,粗纤维(CF)36.39%,粗蛋白质(CP)5.66%,粗脂肪(EE)5.63%,NDF 72.51%,ADF 44.32%,WSC 5.87%。
纤维素酶(活性≥1×104 U/g)、木聚糖酶(活性≥1.2×105 U/g)、β-葡聚糖酶(活性≥4×104 U/g)和果胶酶(H型,活性≥2.5×104 U/g)来源于宁夏某实业集团有限公司;漆酶(活性≥1×105 U/g)来源于济南某生物工程有限公司。复合酶制剂配比参照王玉荣等[17]研究结果,按照纤维素酶:木聚糖酶:β-葡聚糖酶为1∶1∶1进行混合。

1.1.2 青贮制作

将青贮原料随机分为4组,对照组(CK组,不添加任何酶制剂)、C组(添加1.0 g/kg复合酶制剂)、PL组(添加0.5 g/kg果胶酶+1.0 g/kg漆酶)、CPL组(添加1.0 g/kg复合酶制剂+0.5 g/kg果胶酶+1.0 g/kg漆酶);此外,将发酵前青贮原料记为S组。装入真空袋(450 mm×600 mm)中,抽氧密封模拟裹包青贮,在室温25 ℃左右进行青贮发酵,60 d后开包取样,每组5个重复,每个重复取样约1 000 g青贮原料。

1.1.3 水稻秸秆青贮前后营养物质含量测定

各试验组青贮开袋后(将袋内样品混匀后取样),按照“四分法”取水稻秸秆青贮饲料分析样品,样重500 g左右(单个重复重量),置于烘箱中烘干后再将其粉碎过筛,进行水稻秸秆青贮饲料营养物质含量测定。DM和CP含量按照GB/T 6435—2006的方法测定,EE含量按照GB/T 6433—2006的方法测定,NDF、ADF和总氮(TN)含量分别按照GB/T 24318—2009、GB/T 20806—2006、NY/T 1459—2007的方法测定。WSC含量的测定参考Zahiroddini等[18]的方法。剩余部分样品保存于干燥罐中,用于后续体外发酵试验。
水稻秸秆青贮后总可消化养分(total digestible nutrient,TDN)和相对饲用价值(relative feed value,RFV)的计算公式如下:
TDN(%)=(88.9-ADF×0.779)×100[19];
RFV=(TDN×120/NDF)/1.29[20]。

1.2 体外发酵试验

1.2.1 供体动物饲养与管理

以不同酶制剂组合的水稻秸秆青贮样品进行体外发酵试验。体外瘤胃液供体动物为3只体重在(357.0±23.0) kg并安装永久性瘤胃瘘管的健康成年湘西黄牛。饲粮的配制参考《肉牛饲养标准》(NY/T 815—2004),按照1.3倍维持需要设计。每日08:30和18:30各饲喂1次,自由饮水。饲粮组成及营养水平见表1。
表1 饲粮组成及营养水平(干物质基础)

Table 1 Composition and nutrient levels of the diet (DM basis)%

项目 Items 含量 Content
原料 Ingredients
玉米 Corn 25.00
豆粕 Soyabean meal 8.70
稻谷 Rice 28.00
麦麸 Wheat bran 14.00
油糠 Oil bran 7.00
喷浆玉米皮 Sprayed corn husk 2.00
大豆胚芽粉 Soybean germ meal 3.00
糙米 Rough rice 3.00
大豆皮 Soybean husk 2.00
过瘤胃脂肪粉 Rumen-protected fat meal 0.30
膨化尿素 Puffing urea 0.80
统糠 Rice mill by-product 1.25
预混料 Premix1) 4.95
合计 Total 100.00
营养水平 Nutrient levels2)
粗蛋白质 CP 15.30
粗脂肪 EE 3.90
粗灰分 Ash 7.90
中性洗涤纤维 NDF 34.26
酸性洗涤纤维 ADE 20.28
钙 Ca 0.92
磷 P 0.58

1)预混料为每千克饲粮提供 Premix provided the following per kg of the diet:VA 18 000 IU,VD3 6 400 IU,VE 32 IU,Fe 200 mg,Mn 108 mg,Zn 108 mg,Cu 18 mg,Se 0.4 mg。

2)营养水平为实测值。Nutrient levels were measured values.

1.2.2 人工瘤胃缓冲液和培养液配制

人工瘤胃缓冲液的配制方法参照Menke等[21]。在使用前,将加入还原剂的人工瘤胃缓冲液持续通入二氧化碳,直到人工瘤胃缓冲液颜色变为无色即可。试验前供体牛瘤胃液的采集和保存过程参照邹诗雨等[22]。培养液的制备方法是将1倍体积的人工瘤胃缓冲液(预热到39 ℃)混合2倍体积的瘤胃液而成。

1.2.3 体外发酵操作

采用Menke等[21]的体外产气法,使用分析天平分别称取各组水稻秸秆样品1.0 g,置于厌氧发酵瓶中,保持发酵瓶环境处于39.5 ℃恒温。之后在持续通入二氧化碳气体的条件下取100 mL培养液置于厌氧发酵瓶中,密封体外发酵24 h(恒温水浴摇床中进行)。设立空白试验,每组体外发酵样品设置5个重复。在发酵时间分别为3、6、9、12和24 h时测定产气体积,记录该时刻产气量数据。在体外发酵结束时终止发酵,过滤再烘干后测定其DM降解率和发酵参数。

1.2.4 体外产气量与产气参数的计算

产气量参照Menke等[21]方法进行计算,使用SPSS 13.0软件中的非线性模型进行产气参数的计算,计算公式为:
GP=a+b(1-e-ct)。
式中:GP为t时刻产气量(mL);a为快速降解部分产气量(mL);b为慢速降解部分产气量(mL);c为慢速降解部分产气速率(%/h);a+b为潜在产气量(mL);t为发酵时间(h)。

1.2.5 体外瘤胃发酵特性

体外发酵24 h后(测定完产气量),即刻使用pH计测定发酵液的pH,记录每个发酵瓶中的pH,之后将发酵液静置转移到离心管中,做好标记并放置于-20 ℃冰箱保存,过滤的滤液采用气相色谱仪(GC-2010,岛津株式会社,日本)测定挥发性脂肪酸(VFA)含量[23],NH3-N含量采用苯酚-次氯酸钠比色法(T/CAAA 003—2018)测定。

1.2.6 体外降解特性评定

按下列公式计算体外瘤胃发酵底物营养物质降解率:
水稻秸秆中某营养物质降解率(%)=[(发酵前水稻秸秆中该营养物质含量-发酵后水稻秸秆中该营养物质含量)/(发酵前水稻秸秆中该营养物质含量)]×100。

1.3 数据分析

各项数据采用Excel 2021进行收集、记录和整理,使用SPSS 25.0软件进行单因素方差分析(one-way ANOVA),采用Duncan氏法进行多重比较。数据均用平均值±标准差表示,P<0.05为差异显著。

2 结果

2.1 不同酶制剂组合对水稻秸秆青贮前后营养成分的影响

由表2可知,S组的DM含量最高,显著高于其他各组(P<0.05);PL组的DM含量显著高于CK、C、CPL组(P<0.05);CK、C、CPL组之间DM含量无显著差异(P>0.05)。S组的CP含量显著低于其他各组(P<0.05),其他各组之间CP含量无显著差异(P>0.05)。CPL组的EE含量显著高于其他各组(P<0.05),PL组的EE含量显著高于S、CK组(P<0.05),C组的EE含量显著高于S组(P<0.05)。CPL组的NDF含量显著低于其他各组(P<0.05),S组的NDF含量显著高于C、PL组(P<0.05)。CPL组的NDF含量最低,显著低于S、CK、C组(P<0.05)。S组的WSC含量最高,显著高于其他各组(P<0.05);CPL组的WSC含量最低,显著低于其他各组(P<0.05);CK、C、PL组之间WSC含量无显著差异(P>0.05)。CPL组的TDN最高,显著高于S、CK、C组(P<0.05)。CPL组的RFV最高,显著高于其他各组(P<0.05);PL组的RFV显著高于S组(P<0.05)。
表2 不同酶制剂组合对水稻秸秆青贮前后营养成分的影响(风干基础)

Table 2 Effects of different enzyme preparation combinations on nutrient composition of rice straw before and after silage (air-dry basis)%

项目
Items		 组别 Groups P值
P-value
S CK C PL CPL
干物质 DM 35.67±0.35a 31.46±0.30c 30.96±0.32c 32.30±0.49b 31.28±0.43c <0.001
粗蛋白质 CP 5.64±0.04b 7.28±0.30a 7.41±0.34a 7.72±0.63a 7.85±0.59a 0.001
粗脂肪 EE 5.63±5.66d 6.36±0.82cd 6.96±0.26bc 7.65±0.42b 8.72±0.31a <0.001
中性洗涤纤维 NDF 72.90±0.82a 70.56±2.01ab 69.18±0.47b 68.57±1.09b 63.79±1.48c 0.007
酸性洗涤纤维 ADF 44.13±0.06a 43.28±0.21a 43.57±0.25a 39.43±1.73ab 36.31±3.73b 0.031
可溶性碳水化合物 WSC 5.87±0.27a 1.84±0.02b 2.08±0.22b 1.90±0.03b 1.31±0.26c 0.041
总可消化养分 TDN 54.52±0.04b 55.18±0.16b 54.96±0.19b 58.19±1.35ab 60.61±2.91a 0.031
相对饲用价值 RFV 69.57±0.73c 72.78±2.28bc 72.91±0.24bc 78.93±0.57b 88.47±6.30a 0.009

同行数据肩标不同小写字母表示差异显著(P<0.05),相同或无字母表示差异不显著(P>0.05)。下表同。

In the same row, values with different small letter superscripts mean significant difference (P<0.05), while with the same or no letter superscripts mean no significant difference (P>0.05). The same as below.

2.2 不同酶制剂组合对水稻秸秆青贮体外发酵产气量和产气参数的影响

由表3可知,CK组的24 h累积产气量最低,显著低于其他各组(P<0.05);C、PL、CPL组之间24 h累积产气量无显著差异(P>0.05)。CK组的快速降解部分产气量最高,显著高于其他各组(P<0.05);C组的快速降解部分产气量显著高于PL、CPL组(P<0.05),CPL组的快速降解部分产气量显著高于PL组(P<0.05)。CPL组的慢速降解部分产气量和潜在产气量最高,显著高于其他各组(P<0.05);C、PL组的慢速降解部分产气量和潜在产气量显著高于CK组(P<0.05)。PL、CPL组的慢速降解部分产气速率显著高于CK、C组(P<0.05)。
表3 不同酶制剂组合对水稻秸秆青贮体外发酵产气量和产气参数的影响

Table 3 Effects of different enzyme preparation combinations on in vitro fermentation gas production and gas production parameters of rice straw silage

项目
Items		 组别 Groups P值
P-value
CK C PL CPL
24 h累积产气量
24 h cumulative gas production/mL		 84.67±0.38b 95.97±2.80a 93.43±0.99a 97.00±3.67a 0.001
产气参数
Gas production
parameter		 快速降解部分的产气量
a/mL		 3.49±0.05a 1.95±0.01b 0.43±0.04d 0.63±0.03c <0.001
慢速降解部分的产气量
b/mL		 104.96±0.30d 113.44±0.33b 115.14±0.96c 116.30±0.09a <0.001
潜在产气量 a+b/mL 108.44±0.25c 115.39±0.33b 115.58±0.99b 116.93±0.11a <0.001
慢速降解部分产气速率
c/(%/h)		 0.06±0.00b 0.06±0.01b 0.07±0.00a 0.07±0.01a 0.008

2.3 不同酶制剂组合对水稻秸秆青贮体外发酵特性的影响

由表4可知,CK组的pH最高,显著高于其他各组(P<0.05);CPL组的pH显著高于C(P<0.05)。CPL组的NH3-N含量最高,显著高于C、CK组(P<0.05);PL、CK组的NH3-N含量显著高于C组(P<0.05)。各组之间乙酸、丙酸、丁酸、异丁酸、戊酸、异戊酸、总挥发性脂肪酸(TVFA)含量及乙酸/丙酸均无显著差异(P>0.05)。
表4 不同酶制剂组合对水稻秸秆青贮体外发酵特性的影响

Table 4 Effects of different enzyme preparation combinations on in vitro fermentation characteristics of rice straw silage

项目
Items		 组别 Groups P值
P-value
CK C PL CPL
pH 6.95±0.03a 6.80±0.06c 6.84±0.03bc 6.88±0.02b 0.004
乙酸 Acetate/(mmol/L) 44.38±0.10 47.20±6.35 44.53±6.31 47.73±7.07 0.899
丙酸 Propionate/(mmol/L) 17.36±1.53 17.48±3.35 18.40±3.26 16.77±1.49 0.888
乙酸/丙酸 Acetate/propionate 2.47±0.20 2.48±0.07 2.31±0.32 2.50±0.02 0.750
异丁酸 Isobutyrate/(mmol/L) 0.40±0.06 0.34±0.08 0.40±0.09 0.37±0.02 0.406
丁酸 Butyrate/(mmol/L) 8.03±0.66 8.09±1.72 8.23±1.70 9.05±0.65 0.753
异戊酸 Isovalerate/(mmol/L) 0.44±0.09 0.32±0.09 0.42±0.12 0.40±0.01 0.322
戊酸 Valerate/(mmol/L) 0.70±0.08 0.75±0.15 0.75±0.14 0.84±0.04 0.573
总挥发性脂肪酸 TVFA/(mmol/L) 72.34±2.37 76.29±10.19 74.93±14.67 77.23±11.36 0.968
氨态氮 NH3-N/(mg/dL) 12.70±1.94b 9.38±1.11c 14.20±0.89ab 16.42±1.43a 0.002

2.4 不同酶制剂组合对水稻秸秆青贮体外发酵营养物质降解率的影响

由表5可知,C、PL、CPL组的DM降解率显著高于CK组(P<0.05),C、PL、CPL组之间DM降解率无显著差异(P>0.05)。CPL组的CP降解率最高,显著高于CK组(P<0.05)。CPL组的NDF降解率最高,显著高于其他各组(P<0.05);PL组的NDF降解率显著高于CK组(P<0.05)。各组之间ADF降解率无显著差异(P>0.05)。
表5 不同酶制剂组合对水稻秸秆青贮体外发酵营养物质降解率的影响

Table 5 Effects of different enzyme preparation combinations on in vitro fermentation nutrient degradation rates of rice straw silage%

项目
Items		 组别 Groups P值
P-value
CK C PL CPL
干物质 DM 38.46±0.75b 42.63±0.29a 43.30±0.62a 42.62±1.16a <0.001
粗蛋白质 CP 45.95±4.60b 51.15±4.38ab 53.55±1.91ab 56.87±0.60a 0.015
中性洗涤纤维 NDF 38.92±1.18c 40.72±0.18bc 41.46±0.98b 47.36±0.76a 0.002
酸性洗涤纤维 ADF 42.22±1.50 46.71±4.19 46.89±1.15 45.79±3.03 0.336

3 讨论

3.1 不同酶制剂组合对水稻秸秆青贮前后营养成分的影响

青贮中添加混合酶制剂可以提高青贮饲料发酵品质和营养品质[24-25]。本研究通过添加复合酶制剂、果胶酶+漆酶、复合酶制剂+果胶酶+漆酶的不同组合来分析水稻秸秆青贮营养成分的变化,发现水稻秸秆青贮后的DM、NDF、ADF、WSC含量低于青贮前,而CP、EE含量和TDN、RVF高于青贮前。水稻秸秆青贮后的CP和EE含量均高于青贮前,而NDF和ADF含量低于青贮前,这与吕建敏等[26]的试验结果一致。研究报道,青贮过程中添加纤维素酶可以提高青贮饲料CP含量,其主要原因可能是添加酶制剂提高了乳酸菌对结构性碳水化合物的降解,促进乳酸菌等微生物不断增殖,从而提高了青贮饲料CP含量[22,27-28],而漆酶和果胶酶与纤维素酶同属于外源性酶制剂,在一定程度上提高了青贮饲料CP含量[29]。添加复合酶制剂+漆酶+果胶酶组的WSC含量比对照组高,可能是由于秸秆细胞壁主要是纤维素、半纤维素等构成,纤维素酶能够分解纤维素、参与水解反应,漆酶能够提高木质纤维素的降解效率[13],降低NDF和ADF含量,从而提高了青贮过程中WSC含量[30⇓-32],而王志敬等[27]和蒋金娟等[33]的研究结果表明,青贮后WSC含量与酶制剂添加量并没有呈现规律性的变化,本研究结果表明添加复合酶制剂+果胶酶+漆酶组青贮后WSC含量显著低于对照组和添加复合酶制剂组,具体机制有待进一步研究。本试验结果显示,添加酶制剂使水稻秸秆青贮中CP、EE含量和TDN、RVF增加,NDF和ADF含量降低,且复合酶制剂+果胶酶+漆酶的组合更有利于水稻秸秆青贮发酵品质和营养品质的提高。

3.2 不同酶制剂组合对水稻秸秆青贮体外发酵产气量和产气参数的影响

产气量的多少是预估青贮饲料发酵程度的重要指标之一[34]。瘤胃产气量主要是由于微生物作用饲料中碳水化合物和蛋白质分解产生的气体组成,产气量越多说明瘤胃内微生物的发酵活动越强[35⇓-37]。此外,产气量也可以间接反映发酵底物的降解程度[21]。本试验中,C、PL、CPL组的24 h累积产气量、慢速降解部分产气量和潜在产气量均显著高于CK组,可能是由于水稻秸秆原料含有较高的纤维素和半纤维素,没有添加剂难以被利用,而酶制剂能够破坏植物细胞壁的纤维结构[38],协同瘤胃微生物降解水稻秸秆原料的纤维素和半纤维素[39],促进微生物分解碳水化合物和蛋白质,从而提高了体外发酵产气量和产气速率[40-41]。本试验结果表明,添加不同酶制剂组合能够提高水稻秸秆青贮体外发酵产气量,且复合酶制剂+果胶酶+漆酶组合发酵效果最优。

3.3 不同酶制剂组合对水稻秸秆青贮体外发酵特性和营养物质降解率的影响

pH是瘤胃微生物生长繁殖的重要条件,保持瘤胃内环境稳定适宜的pH在6.0~7.0[18]。本试验中,各组瘤胃液pH均在此范围,C、PL、CPL组的瘤胃液pH显著低于CK组,这与赵超等[42]的试验结果一致,可能是因为不同酶制剂组合有助于水稻秸秆的发酵,将水稻秸秆中的营养成分降解为瘤胃微生物更易利用的物质,从而产生了更多的酸性物质。VFA是维持牛或者其他反刍动物生命的重要能量来源,参与瘤胃代谢的重要环节,反刍动物70%~80%的能量来源于VFA[43-44]。VFA含量受饲粮营养水平、饲料添加剂和瘤胃内环境等的影响[45-46]。本试验结果表明,各组之间乙酸和TVFA含量差异并不显著。Sheperd等[47]试验结果表明,添加酶制剂对玉米青贮TVFA和乙酸含量无显著影响;但一些研究显示青贮过程中添加酶制剂可以显著提高发酵后饲料原料体外发酵的TVFA含量[27,48-49],可能是VFA组成的变化取决于发酵底物的营养组成,而发酵底物的营养组成与各组发酵过程中所添加酶制剂的种类、活性不同有关[50]。NH3-N是瘤胃微生物分解代谢含氮物质的最终产物,瘤胃微生物合成蛋白需要NH3-N含量在0.35~29.00 mg/dL[51-52]。本试验中,各组体外瘤胃发酵液NH3-N含量均处于正常范围内,添加果胶酶+漆酶和复合酶制剂+果胶酶+漆酶组的体外瘤胃发酵液NH3-N含量显著高于对照组,说明青贮中添加酶制剂促进了体外发酵瘤胃微生物对青贮发酵底物中含氮化合物的分解[53-54],使NH3-N含量升高。添加复合酶制剂组的体外瘤胃发酵液NH3-N含量比较低,可能是由于NH3-N含量过高导致微生物合成蛋白质的作用加强[55],从而使NH3-N含量降低,具体机制有待进一步研究。总体来看,添加复合酶制剂+漆酶+果胶酶的青贮体外发酵效果最优。
大量研究表明,青贮饲料中添加酶制剂能够提高瘤胃营养物质降解率[17,27,56]。本研究中,添加复合酶制剂+漆酶+果胶酶组的体外瘤胃DM、CP、NDF降解率显著提高,与前人研究结果一致,说明添加复合酶制剂+漆酶+果胶酶在一定程度上能够提升水稻秸秆瘤胃微生物的利用效率,其主要原因可能是发酵过程中酶制剂能够破坏植物细胞壁结构,并且将大分子化合物分解为小分子化合物,提高了瘤胃微生物对水稻秸秆中纤维素等的分解效率[40-41]。此外,添加复合酶制剂+漆酶+果胶酶在青贮过程中可能发挥了协同作用,进一步提高了水稻秸秆中主要营养物质的体外瘤胃降解率[38-39]。

4 结论

① 添加不同酶制剂组合能够提高水稻秸秆青贮发酵品质,在水稻秸秆青贮中添加复合酶制剂+果胶酶+漆酶的组合提高了EE含量和TDN、RVF,降低了NDF和ADF含量。
② 添加不同酶制剂组合能够提高水稻秸秆青贮体外发酵累积产气量、慢速降解部分产气量和潜在产气量,增加NH3-N含量,提高DM、CP和NDF降解率。
③ 在实际生产中,水稻秸秆青贮过程中建议添加复合酶制剂(纤维素酶+木聚糖酶+β-葡聚糖酶)+果胶酶+漆酶组合,可有效改善水稻秸秆的饲用价值。

References

Publishing order | Descend order by publishing year | Descend order by cited within
[1]
吕中旺, 王建, 孙鹏, 等. 秸秆主产区三大作物秸秆饲用品质分析与评价[J]. 草业科学, 2018, 35(8):2016-2021.

LV Z W, WANG J, SUN P, et al. Forage quality of three crop straws in a main producing area[J]. Pratacultural Science, 2018, 35(8):2016-2021. (in Chinese)

[2]
梁榕旺, 徐淑莉. 我国秸秆资源现状及其利用[J]. 畜牧与饲料科学, 2011, 32(11):21-23.

LIANG R W, XU S L. Current situation and utilization of straw resources in China[J]. Animal Husbandry and Feed Science, 2011, 32(11):21-23. (in Chinese)

[3]
赵楚琦, 王喜成, 姜涛, 等. 秸秆饲料化处理技术[J]. 吉林畜牧兽医, 2022, 43(11):109-110.

ZHAO C Q, WANG X C, JIANG T, et al. Straw feed treatment technology[J]. Jilin Animal Husbandry and Veterinary Medicine, 2022, 43(11):109-110. (in Chinese)

[4]
吴永杰, 丁浩, 邵涛, 等. 酶制剂对水稻秸秆青贮发酵品质及体外消化特性的影响[J]. 草业学报, 2022, 31(8):167-177.

DOI

WU Y J, DING H, SHAO T, et al. Effects of enzyme additives on fermentation quality and in vitro digestion characteristics of rice straw silage[J]. Acta Prataculturae Sinica, 2022, 31(8):167-177. (in Chinese)

[5]
陈东, 武伟成, 陈坤, 等. 全株水稻青贮替代全株玉米青贮对泌乳奶牛生产性能、血清生化指标、抗氧化能力和免疫能力的影响[J]. 中国饲料, 2022(21):125-132.

CHEN D, WU W C, CHEN K, et al. Effects of whole plant rice silage substituting whole plant corn silage on productive performance,serum biochemical indices,antioxidant capacity and immune capacity of lactating dairy cows[J]. China Feed, 2022(21):125-132. (in Chinese)

[6]
HOU M L, GENTU G, LIU T Y, et al. Silage preparation and fermentation quality of natural grasses treated with lactic acid bacteria and cellulase in meadow steppe and typical steppe[J]. Asian-Australasian Journal of Animal Sciences, 2017, 30(6):788-796.

DOI PMID

[7]
CHEN Q, MARSHALL M N, GEIB S M, et al. Effects of laccase on lignin depolymerization and enzymatic hydrolysis of ensiled corn stover[J]. Bioresource Technology, 2012, 117:186-192.

DOI PMID

[8]
周力, 高占红, 张峰硕, 等. 小麦饲料中添加木聚糖酶对高原型藏羊胃肠道发育的影响[J]. 畜牧兽医学报, 2023, 54(1):227-238.

ZHOU L, GAO Z H, ZHANG F S, et al. Effects of xylanase supplementation in wheat diet on gastrointestinal development of plateau Tibetan sheep[J]. Acta Veterinaria et Zootechnica Sinica, 2023, 54(1):227-238. (in Chinese)

[9]
覃雯, 尹立伟, 胡婷, 等. 野生茯苓鉴定及其木质纤维素降解酶系研究[J/OL]. 广西植物:1-13[2022-12-30]. http://kns.cnki.net/kcms/detail/45.1134.q.20220831.1052.002.html.

QIN W, YIN L W, HU T, et al. Identification of wild Wolfiporia cocos and studies on its lignocellulolytic enzymes[J/OL]. Guihaia:1-13[2022-12-30]. http://kns.cnki.net/kcms/detail/45.1134.q.20220831.1052.002.html. in Chinese)

[10]
赵小雪, 王仕玉, 郭凤根, 等. 乳酸菌及纤维素酶对不同藜麦秸秆青贮发酵品质的影响[J]. 草地学报, 2022, 30(10):2827-2833.

DOI

ZHAO X X, WANG S Y, GUO F G, et al. Effects of lactic acid bacteria and cellulase on fermentation quality of straw silage of different Chenopodium quinoa Willd[J]. Acta Agrestia Sinica, 2022, 30(10):2827-2833. (in Chinese)

[11]
杨烈, 胡茂雷, 李玲玉, 等. 添加乳酸菌与纤维素酶对‘Tifton 85’狗牙根青贮发酵品质的影响[J]. 中国草地学报, 2022, 44(6):91-97.

YANG L, HU M L, LI L Y, et al. Effects of lactic acid bacteria and cellulase treatments on the fermentation quality of ‘Tifton 85’ bermudagrass silage[J]. Chinese Journal of Grassland, 2022, 44(6):91-97. (in Chinese)

[12]
DEAN D B, ADESOGAN A T, KRUEGER N, et al. Effect of fibrolytic enzymes on the fermentation characteristics,aerobic stability,and digestibility of bermudagrass silage[J]. Journal of Dairy Science, 2005, 88(3):994-1003.

DOI

[13]
JANUSZ G, PAWLIK A, ŚWIDERSKA-BUREK U, et al. Laccase properties,physiological functions,and evolution[J]. International Journal of Molecular Sciences, 2020, 21(3):966.

DOI

[14]
MATE D M, ALCALDE M. Laccase:a multi-purpose biocatalyst at the forefront of biotechnology[J]. Microbial Biotechnology, 2017, 10(6):1457-1467.

DOI

[15]
秦雪丽, 夏颖, 赵杰, 等. 利用重组里氏木霉高效降解秸秆的研究[J]. 高校化学工程学报, 2018, 32(6):1374-1381.

QIN X L, XIA Y, ZHAO J, et al. Study on straw degradation using recombinant Trichoderma reesei[J]. Journal of Chemical Engineering of Chinese Universities, 2018, 32(6):1374-1381. (in Chinese)

[16]
WANG B, SUN Z Q, YU Z. Pectin degradation is an important determinant for alfalfa silage fermentation through the rescheduling of the bacterial community[J]. Microorganisms, 2020, 8(4):488.

DOI

[17]
王玉荣, 陶莲, 冯文晓, 等. 不同酶、菌及复合酶菌制剂对水稻秸秆青贮品质与瘤胃降解率的影响[J]. 中国饲料, 2019(19):50-57.

WANG Y R, TAO L, FENG W X, et al. The effect of different enzyme or fungus supplementation on fermentation quality,nutrition composition and in situ ruminal degradability of rice straw silage[J]. China Feed, 2019(19):50-57. (in Chinese)

[18]
ZAHIRODDINI H, BAAH J, MCALLISTER T A. Effects of microbial inoculants on the fermentation,nutrient retention,and aerobic stability of barley silage[J]. Asian-Australasian Journal of Animal Sciences, 2006, 19(10):1429-1436.

DOI

[19]
NRC. Nutrient requirements of small ruminants:sheep,goats,cervids,and new world camelids[S]. Washington,D.C.: The National Academies Press, 2007.

[20]
董德宽. 饲草的相对饲料值[J]. 中国奶牛, 1990(4):28-29.

DONG D K. The relative feed value of the forage[J]. China Dairy Cattle, 1990(4):28-29. (in Chinese)

[21]
MENKE K H, RAAB L, SALEWSKI A, et al. The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumen liquor in vitro[J]. The Journal of Agricultural Science, 1979, 93(1):217-222.

DOI

[22]
邹诗雨, 陈思葵, 唐启源, 等. 青贮剂对再生稻头季全株青贮品质和体外瘤胃发酵特性的影响[J]. 草业学报, 2021, 30(7):122-132.

DOI

ZOU S Y, CHEN S K, TANG Q Y, et al. Effects of silage additives on quality and in vitro rumen fermentation characteristics of first season ratoon rice whole silage[J]. Acta Prataculturae Sinica, 2021, 30(7):122-132. (in Chinese)

[23]
MUETZEL S, HUNT C L, TAVENDALE M H. Brief communication:evaluating rumen fluid from sheep and cattle as inoculum in a newly developed automated in vitro rumen batch culture system[J]. Proceedings of the New Zealand Society of Animal Production, 2011, 71:240-242.

[24]
王啸林, 冯冠智, 张城瑞, 等. 乳酸菌和纤维素酶对马铃薯渣与玉米秸秆混合青贮发酵品质、有氧稳定性和体外发酵参数的影响[J]. 中国畜牧杂志, 2022, 58(4):201-207.

WANG X L, FENG G Z, ZHANG C R, et al. Effects of lactic acid bacteria and cellulase on fermentation quality,aerobic stability and in vitro fermentation parameters of potato residue and corn straw mixed silage with different proportion[J]. Chinese Journal of Animal Science, 2022, 58(4):201-207. (in Chinese)

[25]
李玉玉, 牟怡晓, 张硕, 等. 青贮专用复合酶制剂调控苜蓿发酵品质及营养成分[J]. 草业科学, 2021, 38(7):1402-1410.

LI Y Y, MU Y X, ZHANG S, et al. Silage-specific compound enzyme regulate alfalfa silage quality and nutrient components[J]. Pratacultural Science, 2021, 38(7):1402-1410. (in Chinese)

[26]
吕建敏, 陈民利, 胡伟莲. 添加酶制剂对青贮玉米秸发酵品质和营养价值的影响[J]. 中国畜牧杂志, 2005, 41(7):18-20.

LV J M, CHEN M L, HU W L. Effect of enzyme preparation on fermentation quality and nutrient value of corn silages[J]. Chinese Journal of Animal Science, 2005, 41(7):18-20. (in Chinese)

[27]
MUCK R E, NADEAU E M G, MCALLISTER T A, et al. Silage review:recent advances and future uses of silage additives[J]. Journal of Dairy Science, 2018, 101(5):3980-4000.

DOI

[28]
王志敬, 吴征敏, 尹福泉, 等. 纤维素分解酶对凤梨渣青贮品质及干物质降解率的影响[J]. 江西农业大学学报, 2022, 44(6):1399-1406.

WANG Z J, WU Z M, YIN F Q, et al. Effects of cellulase on the quality and dry matter degradation rate of pineapple residue silage[J]. Acta Agriculturae Universitatis Jiangxiensis, 2022, 44(6):1399-1406. (in Chinese)

[29]
陈兴, 茅慧玲, 王佳堃, 等. 外源纤维酶制剂对青贮玉米体外发酵特性以及甲烷生成的影响[J]. 动物营养学报, 2013, 25(1):214-221.

DOI

CHEN X, MAO H L, WANG J K, et al. Exogenous fibrolytic enzymes:effects on in vitro fermentation and methane production of corn silage[J]. Chinese Journal of Animal Nutrition, 2013, 25(1):214-221. (in Chinese)

[30]
张适, 吴琼, 尤欢, 等. 添加混合酶制剂对全株玉米青贮发酵品质的影响[J]. 中国畜牧杂志, 2020, 56(6):119-122,129.

ZHANG S, WU Q, YOU H, et al. Effects of mixed enzyme preparations on fermentation quality of whole corn silage[J]. Chinese Journal of Animal Science, 2020, 56(6):119-122,129. (in Chinese)

[31]
张适, 吴琼, 尤欢, 等. 添加不同酶制剂对全株玉米青贮发酵品质的影响[J]. 中国畜牧兽医, 2019, 46(4):1045-1052.

ZHANG S, WU Q, YOU H, et al. Effects of different enzyme preparations on fermentation quality of whole corn silage[J]. China Animal Husbandry & Veterinary Medicine, 2019, 46(4):1045-1052. (in Chinese)

[32]
邓荟芬, 揭红东, 马玉申, 等. 添加酶制剂对饲用苎麻与麦麸混合青贮品质的影响[J]. 中国麻业科学, 2020, 42(2):70-75.

DENG H F, JIE H D, MA Y S, et al. Effects of different enzyme on nutrition and fermentation quality of ramie silage[J]. Plant Fiber Sciences in China, 2020, 42(2):70-75. (in Chinese)

[33]
蒋金娟, 王鸿发, 余超, 等. 半纤维素酶添加量对甘蔗梢青贮品质的影响[J]. 草学, 2022(1):55-60.

JIANG J J, WANG H F, YU C, et al. Effect of hemicellulase supplementation on quality of sugarcane shoot silage[J]. Journal of Grassland and Forage Science, 2022(1):55-60. (in Chinese)

[34]
户林其, 郭伟婷, 赵晓静, 等. 体外产气法评定不同留茬高度对全株玉米青贮体外发酵指标的影响[J]. 饲料研究, 2022, 45(4):61-66.

HU L Q, GUO W T, ZHAO X J, et al. Effect of different stubble heights on in vitro fermentation indexes of whole maize silage by in vitro gas production method[J]. Feed Research, 2022, 45(4):61-66. (in Chinese)

[35]
周恩光, 王虎成, 尚占环. 甜高粱的饲用价值及其绵羊体外瘤胃发酵产气性能研究[J]. 草业学报, 2020, 29(5):43-49.

DOI

ZHOU E G, WANG H C, SHANG Z H. Nutritional value of forage sweet sorghum and its gas production performance evaluated using incubation with sheep rumen fluid in vitro[J]. Acta Prataculturae Sinica, 2020, 29(5):43-49. (in Chinese)

[36]
王芳, 徐元君, 牛俊丽, 等. 体外产气法评价反刍动物饲料营养价值的研究[J]. 中国畜牧兽医, 2016, 43(1):76-83.

WANG F, XU Y J, NIU J L, et al. Nutrient value evaluation of different type feeds by in vitro gas production method[J]. China Animal Husbandry & Veterinary Medicine, 2016, 43(1):76-83. (in Chinese)

[37]
谢小来, 马逢春, 焦培鑫, 等. 添加单宁酸对紫花苜蓿青贮品质及瘤胃体外产气量的影响[J]. 东北农业大学学报, 2021, 52(8):48-56.

XIE X L, MA F C, JIAO P X, et al. Effects of tannins on quality of alfalfa silage and gas production in vitro[J]. Journal of Northeast Agricultural University, 2021, 52(8):48-56. (in Chinese)

[38]
孟梅娟, 涂远璐, 白云峰, 等. 小麦秸秆与米糠粕瘤胃体外发酵组合效应研究[J]. 草业学报, 2016, 25(9):161-172.

DOI

MENG M J, TU Y L, BAI Y F, et al. Study of associative effects of wheat straw mixed with rice bran meal on in vitro fermentation parameters[J]. Acta Prataculturae Sinica, 2016, 25(9):161-172. (in Chinese)

[39]
LI J F, TANG X Y, CHEN S F, et al. Ensiling pretreatment with two novel microbial consortia enhances bioethanol production in sterile rice straw[J]. Bioresource Technology, 2021, 339:125507.

DOI

[40]
庄苏. 纤维水解酶对牧草青贮品质及体外瘤胃发酵特性的研究[D]. 博士学位论文. 南京: 南京农业大学, 2011.

ZHUANG S. Syudy on fibrolytic enzymes on forage silage quality and characteristics of rumen fermentation in vitro[D]. Ph.D.Thesis. Nanjing: Nanjing Agricultural University, 2011. (in Chinese)

[41]
MORGAVI D P, BEAUCHEMIN K A, NSEREKO V L, et al. Synergy between ruminal fibrolytic enzymes and enzymes from Trichoderma longibrachiatum[J]. Journal of Dairy Science, 2000, 83(6):1310-1321.

DOI

[42]
赵超, 马广明, 吕静怡, 等. 添加乳酸菌和纤维素酶对豆渣与桑叶混贮品质及体外瘤胃发酵特性的影响[J]. 动物营养学报, 2021, 33(4):2168-2177.

DOI

ZHAO C, MA G M, LYU J Y, et al. Effects of adding lactic acid bacteria and cellulase on quality of mixed silage of soybean residue and mulberry leaves and rumen fermentation characteristics in vitro[J]. Chinese Journal of Animal Nutrition, 2021, 33(4):2168-2177. (in Chinese)

[43]
童殷迪, 徐志鹏, 玉霞, 等. 不同比例青贮玉米和甜高粱组合对体外瘤胃发酵产气量、甲烷、氢气和挥发性脂肪酸生成的影响[J]. 中国饲料, 2022(7):13-18.

TONG Y D, XU Z P, YU X, et al. Effects of different proportions of corn silage and sweet sorghum on gas production,methane,hydrogen and volatile fatty acids production of in vitro rumen fermentation[J]. China Feed, 2022(7):13-18. (in Chinese)

[44]
毛宏祥, 陆相龙, 金宜全, 等. 反刍家畜瘤胃挥发性脂肪酸生成及模型研究进展[J]. 中国畜牧杂志, 2019, 55(8):35-40.

MAO H X, LU X L, JIN Y Q, et al. Research progress on the mechanism and models of rumen volatile fatty acids in ruminant animals[J]. Chinese Journal of Animal Science, 2019, 55(8):35-40. (in Chinese)

[45]
鲍宏云, 闫素梅, 乔良, 等. 日粮精粗比与维生素A添加水平对奶牛体外瘤胃发酵参数的影响[J]. 饲料工业, 2011, 32(13):40-45.

BAO H Y, YAN S M, QIAO L, et al. Effect of dietary sperm ratio and vitamin A addition level on rumen fermentation parameters in vitro in dairy cows[J]. Feed Industry, 2011, 32(13):40-45. (in Chinese)

[46]
WANG M, WANG R, JANSSEN P H, et al. Sampling procedure for the measurement of dissolved hydrogen and volatile fatty acids in the rumen of dairy cows[J]. Journal of Animal Science, 2016, 94(3):1159-1169.

DOI PMID

[47]
SHEPERD A C, KUNG L,Jr. Effects of an enzyme additive on composition of corn silage ensiled at various stages of maturity[J]. Journal of Dairy Science, 1996, 79(10):1767-1773.

PMID

[48]
欧阳佳良, 张硕, 戚如鑫, 等. 体外法研究不同青贮菌、纤维分解酶及碳源组合青贮稻秸对瘤胃发酵参数及产气量的影响[J]. 饲料工业, 2019, 40(15):36-40.

OUYANG J L, ZHANG S, QI R X, et al. Evaluation of effects of different silage bacteria,cellulolytic enzymes and carbon sources combinations on rumen fermentation parameters and gas production of silage rice straw by in vitro ruminal fermentation method[J]. Feed Industry, 2019, 40(15):36-40. (in Chinese)

[49]
史卉玲, 王连群, 席琳乔, 等. 利用体外产气法研究苜蓿青贮与玉米青贮组合效应的瘤胃发酵特征[J]. 新疆农业科学, 2013, 50(7):1353-1359.

SHI H L, WANG L Q, XI L Q, et al. Rumen rermentation characteristics of vitro gas production of alfalfa silage and corn silage combination effect[J]. Xinjiang Agricultural Sciences, 2013, 50(7):1353-1359. (in Chinese)

[50]
EUN J S, BEAUCHEMIN K A. Enhancing in vitro degradation of alfalfa hay and corn silage using feed enzymes[J]. Journal of Dairy Science, 2007, 90(6):2839-2851.

PMID

[51]
HRISTOV A N, ROPP J K, HUNT C W. Effect of barley and its amylopectin content on ruminal fermentation and bacterial utilization of ammonia-N in vitro[J]. Animal Feed Science and Technology, 2002, 99(1/2/3/4):25-36.

DOI

[52]
OWENS F N, BERGEN W G. Nitrogen metabolism of ruminant animals:historical perspective,current understanding and future implications[J]. Journal of Animal Science, 1983, 57(Suppl.2):498-518.

[53]
李斌, 旦增曲珍, 白玛央金, 等. 不同浓度纤维素酶菌剂处理对小麦、青稞和油菜黄贮体外发酵特性的影响[J]. 动物营养学报, 2021, 33(9):5016-5024.

DOI

LI B, DAN Z Q Z, BAI M Y J, et al. Effects of different concentrations of cellulase agent treatment on fermentation characteristics of wheat,highland barley and rape yellow storages[J]. Chinese Journal of Animal Nutrition, 2021, 33(9):5016-5024. (in Chinese)

[54]
孟庆翔, 张洪军, 戎易, 等. 估测饲料蛋白质瘤胃降解率活体外新方法的研究[J]. 北京农业大学学报, 1991, 17(4):95-101.

MENG Q X, ZHANG H J, RONG Y, et al. A new in vitro procedure for estimation of ruminal protein degradation[J]. Journal of Beijing Agricultural University, 1991, 17(4):95-101. (in Chinese)

[55]
戈婷婷. 不同组合的功能性寡糖对锦江黄牛瘤胃体外发酵的影响[D]. 硕士学位论文. 南昌: 江西农业大学, 2011.

GE T T. Effects of different functional oligosaccharides proportion on the rumen fermentation of Jinjiang cattle in vitro[D]. Master’s Thesis. Nanchang: Jiangxi Agricultural University, 2011. (in Chinese)

[56]
冯鹏, 吴宏达, 孟凡坤, 等. 不同配伍生物制剂对水稻秸秆青贮品质及饲喂价值的影响[J]. 中国饲料, 2021(17):122-128.

FENG P, WU H D, MENG F K, et al. Effect of different compatibility biological agents on silage quality and feeding value of rice stalk[J]. China Feed, 2021(17):122-128. (in Chinese)

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