Chinese Journal of Animal Nutrition >

2024 , Vol. 36 >Issue 10: 6432 - 6447

DOI: https://doi.org/10.12418/CJAN2024.547

RESEARCH PAPER

Effects of Different Roughage Combinations on Growth Performance, Nutrient Apparent Digestibility, Rumen Fermentation Parameters and Microflora of Beef Cattle

  • WANG Jinyu , 1, 2 ,
  • CHEN Qun , 2, * ,
  • CAI Xinyu 1, 2 ,
  • QIU Yulang 2 ,
  • LI Lin 2
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  • 1 College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
  • 2 Institute of Animal Husbandry and Veterinary Medicine, Jilin Academy of Agricultural Sciences, Gongzhuling 136100, China
*professor, E-mail:

Received date: 2024-03-29

  Online published: 2024-10-14

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Abstract

This experiment was conducted to investigate the effects of different roughage combinations on growth performance, nutrient apparent digestibility, rumen fermentation parameters and microflora of beef cattle. Eighteen healthy Simmental crossbred cattle with body weight of (517±9) kg were randomly divided into 3 groups with 6 replicates per group and 1 cattle per replicate. The 3 groups were fed experimental diets which contained 50.0% corn straw+50.0% concentrate (group A), 16.7% Leymus chinensis+33.3% corn straw silage+50.0% concentrate (group B) and 16.7% corn straw+33.3% corn straw silage+50.0% concentrate (group C), respectively. The preparing experiment for 15 days, and the experiment lasted for 90 days. The results showed as follows: 1) the average daily gain (ADG) of group B was significantly higher than that of groups A and C (P<0.05), and the ADG of group C was significantly higher than that of group A (P<0.05). The feed to gain ratio of group B was significantly lower than that of group A (P<0.05). 2) The dry matter (DM) apparent digestibility of group B was significantly higher than that of group A (P<0.05), and the acid detergent fiber (ADF) of group B was significantly higher than that of groups A and C (P<0.05). 3) The rumen fluid ammonia nitrogen (NH3-N) content of groups B and C was significantly lower than that of group A (P<0.05). The contents of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid and total volatile fatty acid in rumen fluid of group B were significantly higher than those of groups A and C (P<0.05), and the rumen fluid butyric acid content of group C was significantly lower than that of group A (P<0.05). 4) The Simpson index of group C was significantly lower than that of group B (P<0.05). The rumen Prevotellaceae_UCG-003 relative abundance of group B was significantly higher than that of group A (P<0.05), the rumen Bacteroidales_RF16_group relative abundance of groups A and B was significantly higher than that of group C (P<0.05), and the rumen WCHB1-41 relative abundance of group C was significantly higher than that of groups A and B (P<0.05). In conclusion, the 16.7% Leymus chinensis+33.3% corn straw silage roughage combination can improve the DM and ADF apparent digestibility, partial volatile fatty acid contents and the relative abundance of beneficial bacteria with increased cellulolytic bacteria activity of beef cattle, and improve the growth performance of beef cattle.

Key words： corn straw silage; growth performance; nutrient apparent digestibility; rumen fermentation parameters; rumen microflora

Cite this article

WANG Jinyu , CHEN Qun , CAI Xinyu , QIU Yulang , LI Lin . Effects of Different Roughage Combinations on Growth Performance, Nutrient Apparent Digestibility, Rumen Fermentation Parameters and Microflora of Beef Cattle[J]. Chinese Journal of Animal Nutrition, 2024 , 36(10) : 6432 -6447 . DOI: 10.12418/CJAN2024.547

随着我国经济的发展,对牛肉的需求逐年增加,肉牛养殖规模逐年增大,对优质粗饲料的需求量也逐渐提高。寒冷和干旱导致优质粗饲料缺乏,我国东北地区每年冬季的粗饲料需求缺口约为1 000万t,缺乏高质量的粗饲料,加上低温的风险,导致冬季肉牛营养不足、体重下降,甚至死亡。玉米秸秆青贮在冬季和夏季被广泛用于养牛,其加工成本低,且青贮处理会破坏粗饲料的木质素结构和阿魏酸酯交联,降低pH,延长储存时间[1]。玉米秸秆青贮是比传统干草制作更好的饲料保存方式[2],相对较高的适口性和能量水平证明了其较高的营养价值,因此通常被用作反刍动物饲粮的主要饲料成分[3]。研究表明,饲粮中适宜的玉米秸秆青贮比例可促进反刍动物的瘤胃发酵,增强营养物质消化能力,提高生长性能[4⇓-6]。青贮发酵后的酸酒糟气味提高了饲料适口性,但较低的物理有效中性洗涤纤维(peNDF)含量可能会导致严重急性呼吸系统综合征和酸中毒[7-8]。有研究表明,瘤胃pH小于5.8的时间不应该大于5~6 h/d,以最大限度地减少严重急性呼吸系统综合征对肉牛健康的干扰[7]。羊草有较强的抗寒冷、耐牧和耐盐碱等特性,对不同环境表现出较强的适应能力[9]。羊草的主要分布区气候属干旱、半干旱草原气候,冬季寒冷干燥,最冷月平均温度为-22.3 ℃,极端最低温度可达-47.5 ℃,可在极端低温条件下存活[10]。研究表明,羊草比玉米秸秆青贮含有更多的粗蛋白质(CP)和粗纤维含量[2,11]。推测羊草和玉米秸秆青贮在反刍动物中混合喂养可能发挥其自身的优势,从而提高反刍动物生长性能。因此,本试验旨在探究相同能量和CP水平饲粮中的不同粗饲料组合对肉牛生长性能、营养物质表观消化率、瘤胃发酵参数及微生物区系的影响,以期为粗饲料的组合应用提供理论基础。

1 材料与方法

1.1 试验设计

本研究根据中国吉林省吉林农业大学动物保健与利用委员会的指导方针进行,所有试验程序均按照《吉林农业大学实验动物护理与使用指南》执行。动物试验经吉林农业大学伦理委员会批准,批准文号:KT2019012。
试验选用月龄相近、体况良好、体重为(517±9) kg的西门塔尔杂交肉牛18头,随机分为3组,每组6个重复,每个重复1头牛。各组之间体重差异不显著(P>0.05)。3组分别饲喂50.0%玉米秸秆+50.0%精料(A组)、16.7%羊草+33.3%玉米秸秆青贮+50.0%精料(B组)、16.7%玉米秸秆+33.3%玉米秸秆青贮+50.0%精料(C组)的试验饲粮。玉米秸秆、羊草和玉米秸秆青贮的营养水平见表1。试验饲粮参考《肉牛饲养标准》(NY/T 815—2004)进行配制,其组成及营养水平见表2。预试期15 d,正试期90 d。
表1 玉米秸秆、羊草和玉米秸秆青贮的营养水平(风干基础)

Table 1 Nutrient levels of corn stalk, Leymus chinensis and corn stalk silage (air-dry basis)%

项目
Items		 玉米秸秆
Corn stalk		 羊草
Leymus chinensis		 玉米秸秆青贮
Corn stalk silage
干物质 DM 90.72 90.77 30.16
粗蛋白质 CP 4.06 4.81 7.05
粗脂肪 EE 0.41 1.12 1.16
中性洗涤纤维 NDF 76.20 67.59 58.53
酸性洗涤纤维 ADF 50.80 45.70 44.80
钙 Ca 2.40 1.70 4.80
磷 P 0.07 0.09 0.21

实测值

measured values。

表2 试验饲粮组成及营养水平(风干基础)

Table 2 Composition and nutrient levels of experimental diets (air-dry basis)%

项目
Items		 组别 Groups
A B C
原料 Ingredients
玉米秸秆 Corn straw 50.00 16.70
羊草 Leymus chinensis 16.70
玉米秸秆青贮 Corn straw silage 33.30 33.30
玉米 Corn 37.00 36.50 40.50
小麦麸 Wheat bran 4.30
棉籽粕 Cottonseed meal 9.00 6.40 3.70
玉米蛋白粉 Corn gluten meal 1.00 3.00
食盐 NaCl 0.70 0.70 0.70
石粉 Limestone 0.60 0.60 0.60
小苏打 NaHCO3 0.50 0.50 0.50
磷酸氢钙 CaHPO4 0.40 0.20 0.20
预混料 Premix1) 0.80 0.80 0.80
合计 Total 100.00 100.00 100.00
营养水平 Nutrient levels2)
综合净能 NEmf/(MJ/kg) 6.48 6.48 6.48
粗蛋白质 CP 9.54 9.55 9.54
粗脂肪 EE 2.47 2.77 2.64
中性洗涤纤维 NDF 43.86 37.34 37.14
酸性洗涤纤维 ADF 27.84 25.34 25.25
钙 Ca 0.54 0.54 0.51
磷 P 0.33 0.31 0.27

1)每千克预混料包含 One kg premix contained the following:VA 200 000 IU,VD 325 000 IU,VE 4 000 IU,Fe 3 500 mg,Mn 2 000 mg,Zn 1 500 mg,Cu 550 mg,I 30 mg,Se 15 mg,Co 15 mg,Ca 150 g,P 60 g。

2)综合净能为计算值,参照《肉牛饲养标准》(NY/T 815—2004)计算,其余为测定值。NEmf was a calculated value, calculated according to the Beef Cattle Feeding Standards (NY/T 815—2004), while the others were measured values.

1.2 饲养管理

试验动物采用栓系饲养。在预试期间对试验牛进行驱虫、健胃。试验期内保证牛舍清洁,各组的饲养环境和管理一致,所有肉牛自由采食和饮水。每日07:00和16:00各饲喂1次,先粗后精。

1.3 测定指标及方法

1.3.1 生长性能

正试期第1、60、90天晨饲前称重并记录体重数据,计算每头牛平均日增重(ADG);正试期间,记录每头牛的喂料量,每3 d记录1次剩料量,每2周测定剩余料的饲粮干物质(DM)含量,计算干物质采食量(DMI);利用DMI和ADG计算料重比(F/G)。计算公式如下:

ADG(kg/d)=(终末体重-初始体重)/试验天数;

DMI(kg/d)=每日饲粮采食量×饲粮DM含量;

F/G=DMI/ADG。

1.3.2 营养物质表观消化率

饲料原料、饲粮及粪便中DM含量的测定采用烘干法(GB/T 6435—2014),CP含量的测定采用凯氏定氮法(GB/T 6432—2018),粗脂肪(EE)含量的测定采用索氏浸提法(GB/T 6433—2006),中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量的测定采用范氏法[12],钙、磷含量的测定分别参照GB/T 6436—2018和GB/T 6437—2018。利用酸不溶灰分(AIA)作内源指示剂,营养物质表观消化率计算方法参照Zhong等[13]。

1.3.3 瘤胃液的采集与检测

正试期最后1天,每组选取3头试验牛,晨饲前使用口腔导管每头牛抽取50 mL瘤胃液,无菌纱布4层过滤,测定瘤胃液pH后分装。一部分在离心机中4 400×g离心10 min,取上清液加入偏磷酸,-20 ℃保存,测定氨态氮(NH3-N)和挥发性脂肪酸(VFA)含量;另一部分于5 mL冻存管分装,放入液氮速冻,带回实验室后-80 ℃保存,用于测定瘤胃微生物区系。

1.3.3.1 瘤胃发酵参数

用PHB-5型笔式便携式pH计现场测定瘤胃液pH。瘤胃液NH3-N含量用比色法[4]测定。采用Agilent DB-FFAP毛细管柱(30 m×250 μm×0.25 μm)气相色谱仪测定VFA含量。

1.3.3.2 瘤胃微生物区系

试验样品送至上海派森诺生物有限公司进行高通量测序,利用Illumina公司的TruSeq Nano DNA LT Library Prep Kit进行测序文库的制备。选用长度约为468 bp左右的细菌16S rRNA基因的高度可变的V3~V4区用来测序,选用细菌通用引物338上游(5'-ACTCCTACGGGAGGCAGCA-3')和806下游(5'-GGACTACHVGGGTWTCTAAT-3')进行PCR扩增。用2%琼脂糖凝胶电泳处理所有PCR产物,用AxyPrep DNA凝胶回收试剂盒(美国AXYGEN公司)回收切取目的片段。PCR产物利用Quant-iT PicoGreen dsDNA Assay Kit在Microplate reader(FLx800,美国BioTek公司)上进行定量。接着利用TruSeq Nano DNA LT Library Prep Kit(美国Illumina公司)进行建库。在Illumina NovaSeq机器上利用NovaSeq 6000 SP Reagent Kit (500 cycles)进行高通量测序。

1.4 数据统计与分析

采用Excel 2016对试验数据进行初步整理,采用SPSS 20.0软件对试验数据进行单因素方差分析,并采用Duncan氏法进行多重比较。结果用平均值和均值标准误(SEM)表示,P<0.05为差异显著性水平。

2 结果与分析

2.1 不同粗饲料组合对肉牛生长性能的影响

由表3可知,各组之间终末体重和DMI无显著差异(P>0.05)。B、C组的ADG显著高于A组(P<0.05),且B组的ADG显著高于C组(P<0.05)。B组的F/G显著低于A组(P<0.05)。
表3 不同粗饲料组合对肉牛生长性能的影响

Table 3 Effects of different roughage combinations on growth performance of beef cattle

项目
Items		 组别 Groups SEM P值
P-value
A B C
初始体重 IBW/kg 505.00 512.33 534.00 8.85 0.436
终末体重 FBW/kg 594.17 627.50 636.67 10.46 0.237
干物质采食量 DMI/(kg/d) 10.35 11.17 10.56 0.16 0.089
平均日增重 ADG/(kg/d) 0.99c 1.28a 1.14b 0.04 0.002
料重比 F/G 10.45a 8.73b 9.31ab 0.32 0.044

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 不同粗饲料组合对肉牛营养物质表观消化率的影响

由表4可知,各组之间CP、EE、NDF表观消化率无显著差异(P>0.05)。B组的DM表观消化率显著高于A组(P<0.05),提高了7.0%。B组的ADF表观消化率显著高于A、C组(P<0.05),分别提高7.6%、9.9%。
表4 不同粗饲料组合对肉牛营养物质表观消化率的影响

Table 4 Effects of different roughage combinations on nutrient apparent digestibility of beef cattle%

项目
Items		 组别 groups SEM P值
P-value
A B C
干物质 DM 74.53b 79.73a 76.96ab 0.01 0.035
粗蛋白质 CP 72.64 73.73 73.93 0.01 0.875
粗脂肪 EE 82.87 85.35 81.98 0.01 0.110
中性洗涤纤维 NDF 68.22 74.29 69.92 0.01 0.078
酸性洗涤纤维 ADF 61.83b 71.24a 62.84b 0.02 <0.001

2.3 不同粗饲料组合对肉牛瘤胃发酵参数的影响

由表6可知,各组之间瘤胃液pH、异戊酸含量和乙酸/丙酸差异不显著(P>0.05)。B、C组的瘤胃液NH3-N含量显著低于A组(P<0.05)。B组的瘤胃液乙酸、丙酸、丁酸、异丁酸、戊酸和总挥发性脂肪酸含量均显著高于A、C组(P<0.05),且C组的瘤胃液丁酸含量显著低于A组(P<0.05)。
表6 不同粗饲料组合对肉牛瘤胃发酵参数的影响

Table 6 Effects of different roughage combinations on rumen fermentation parameters of beef cattle

项目
Items		 组别 Groups SEM P值
P-value
A B C
pH 6.83 6.76 6.79 0.02 0.223
氨态氮 NH3-N/(mmol/L) 11.46a 9.42b 10.15b 0.34 0.016
乙酸 Acetic acid/(mmol/L) 12.69b 19.62a 12.89b 1.34 0.021
丙酸 Propionic acid/(mmol/L) 6.69b 9.50a 6.79b 0.55 0.027
丁酸 Butyric acid/(mmol/L) 5.16b 7.43a 4.46c 0.45 <0.001
异丁酸 Isobutyric acid/(mmol/L) 0.69b 0.83a 0.66b 0.03 0.031
戊酸 Valeric acid/(mmol/L) 0.44b 0.61a 0.37b 0.04 0.003
异戊酸 Isovaleric acid/(mmol/L) 0.68 0.84 0.65 0.04 0.055
总挥发性脂肪酸 TVFA/(mmol/L) 26.35b 38.83a 25.82b 2.37 0.008
乙酸/丙酸 Acetic acid/propionic acid 1.91 2.06 1.90 0.05 0.370

2.4 不同粗饲料组合对肉牛瘤胃微生物区系的影响

2.4.1 瘤胃微生物Alpha多样性分析

2.4.1.1 稀释曲线和等级聚类曲线

由图1可知,3组中肉牛瘤胃液9个样品的稀释曲线,当测序量达到3 894时,已经趋近于平缓,表明测序数据量足够。
图1 稀释曲线

A1、A4、A8分别代表A组的3个重复;B1、B4、B8分别代表B组的3个重复;C1、C4、C8分别代表C组的3个重复。下图同。

Fig.1 Rarefaction curve

A1, A4 and A8 represented 3 replicates in group A, respectively; B1, B4 and B8 represented 3 replicates in group B, respectively; C1, C4 and C8 represented 3 replicates in group A, respectively. The same as below.

由图2可知,在水平方向上,相较于A、C组,B组的曲线跨度越大,所以物种的丰富度更高。在垂直方向上,A组的曲线平滑程度更陡峭,所以物种分布越不均匀;而B组的物种分布更均匀。
图2 等级聚类曲线

Fig.2 Rank cluster curve

2.4.1.2 不同粗饲料组合对肉牛瘤胃微生物Alpha多样性的影响

由表7可知,3组的文库覆盖率均在98.3%以上,说明样品的测序量均合理,可以很好的反映瘤胃液中群落结构多样性。各组之间Chao1指数和Shannon指数差异不显著(P>0.05)。C组的Simpson指数显著低于B组(P<0.05)。
表7 肉牛瘤胃微生物Alpha多样性指数分析

Table 7 Analysis of rumen microbial Alpha diversity indexes of beef cattle

项目
Items		 组别 Groups SEM P值
P-value
A B C
Chao1指数 Chao1 index 2 974.176 7 3 716.636 7 3 658.986 7 206.683 4 0.297
文库覆盖率 Goods coverage 0.989 3 0.985 2 0.983 3 0.001 2 0.102
Shannon指数 Shannon index 9.486 7 10.057 5 9.745 2 0.136 2 0.253
Simpson指数 Simpson index 0.993 5ab 0.996 2a 0.990 4b 0.001 0 0.032

2.4.2 瘤胃微生物Venn图

由图3可知,A、B和C组的操作分类单元(OTU)数目分别为6 926、8 707、8 095个,共有的OTU数目为1 119个,特有的OTU数目分别为4 605、6 382、5 674个。
图3 瘤胃微生物Venn图

A:A组 group A;B :B组 group B;C:C组 group C。

Fig.3 Venn diagram of rumen microorganisms

2.4.3 瘤胃微生物门水平菌群结构

由图4可知,3组中拟杆菌门(Bacteroidota)分别占总细菌门类的62%、73%、71%,厚壁菌门(Firmicutes)分别占总细菌门类的26%、20%、16%,变形菌门(Proteobacteria)分别占总细菌门类的3%、2%、6%,且这3种菌门均为3组的优势菌门,占总门类的90%以上。由表8可知,各组之间瘤胃Bacteroidota、Firmicutes和Proteobacteria相对丰度差异不显著(P>0.05)。
图4 瘤胃微生物门水平菌群结构

Bacteroidota:拟杆菌门;Firmicutes:厚壁菌门;Proteobacteria:变形菌门;Verrucomicrobiota:疣微菌门;Patescibacteria:超级细菌门;Spirochaetota:螺旋菌门;Fibrobacterota:纤维杆菌门;Cyanobacteria:蓝藻菌门;Desulfobacterota:热脱硫杆菌门;Actinobacteriota:放线菌门;Others:其他。

Fig.4 Microflora structure of rumen microorganism at phylum level

表8 不同粗饲料组和对肉牛瘤胃微生物门水平相对丰度的影响

Table 8 Effects of different roughage combinations on rumen microorganism relative abundance at phylum level of beef cattle%

项目
Items		 组别 Groups SEM P值
P-value
A B C
拟杆菌门 Bacteroidota 0.615 6 0.731 6 0.707 4 0.025 4 0.139
厚壁菌门 Firmicutes 0.258 6 0.195 6 0.162 4 0.019 3 0.102
变形菌门 Proteobacteria 0.033 9 0.020 7 0.059 0 0.011 0 0.405
疣微菌门 Verrucomicrobiota 0.052 5 0.015 8 0.018 1 0.008 3 0.112
超级细菌门 Patescibacteria 0.010 0 0.005 8 0.012 2 0.001 4 0.173
螺旋菌门 Spirochaetota 0.005 1 0.003 4 0.003 0 0.000 5 0.175
纤维杆菌门 Fibrobacterota 0.007 7 0.001 5 0.000 6 0.001 4 0.051
蓝藻菌门 Cyanobacteria 0.001 9 0.001 0 0.001 7 0.000 3 0.494
热脱硫杆菌门 Desulfobacterota 0.001 4 0.001 3 0.001 7 0.000 2 0.797
放线菌门 Actinobacteriota 0.000 6 0.001 1 0.000 7 0.000 2 0.338
其他 Others 0.012 8 0.022 2 0.033 3 0.005 5 0.351

2.4.4 瘤胃微生物属水平菌群结构

由图5可知,本试验在属水平进行了进一步分析,普雷沃氏菌属(Prevotella)、F082、理研菌科RC9肠道群(Rikenellaceae_RC9_gut_group)均为3组的优势菌属。由表9可知,C组的瘤胃WCHB1-41相对丰度显著高于A、B组(P<0.05)。B组的瘤胃普雷沃氏菌科UCG-003(Prevotellaceae_UCG-003)相对丰度显著高于A组(P<0.05),与C组差异不显著(P>0.05)。A、B组的瘤胃拟杆菌目RF16群(Bacteroidales_RF16_group)相对丰度显著高于C组(P<0.05)。
图5 瘤胃微生物属水平菌群结构

Prevotella:普雷沃氏菌属;Rikenellaceae_RC9_gut_group:理研菌科RC9肠道群;Prevotellaceae_UCG-001:普雷沃氏菌科UCG-001;Prevotellaceae_UCG-003:普雷沃氏菌科UCG-003;Bacteroidales_RF16_group:拟杆菌目RF16群;Acinetobacter:不动杆菌属;Others:其他。

Fig.5 Microflora structure of rumen microorganism at genus level

表9 不同粗饲料组和对肉牛瘤胃微生物属水平相对丰度的影响

Table 9 Effects of different roughage combinations on rumen microorganism relative abundance at genus level of beef cattle%

项目
Items		 组别 Groups SEM P值
P-value
A B C
普雷沃氏菌属 Prevotella 0.209 4 0.269 0 0.286 5 0.017 3 0.162
F082 0.223 9 0.136 3 0.184 7 0.025 7 0.435
理研菌科RC9肠道群
Rikenellaceae_RC9_gut_group		 0.114 6 0.121 8 0.132 2 0.013 4 0.895
普雷沃氏菌科UCG-001
Prevotellaceae_UCG-001		 0.050 7 0.036 4 0.060 0 0.005 1 0.168
UCG-004 0.013 9 0.034 3 0.022 4 0.004 3 0.143
WCHB1-41 0.014 2b 0.011 5b 0.048 0a 0.006 1 <0.001
普雷沃氏菌科UCG-003
Prevotellaceae_UCG-003		 0.009 6b 0.057 8a 0.026 3ab 0.008 4 0.026
拟杆菌目RF16群
Bacteroidales_RF16_group		 0.022 4a 0.032 9a 0.006 1b 0.004 3 0.005
不动杆菌属 Acinetobacter 0.037 6 0.012 9 0.006 1 0.010 2 0.476
UCG-010 0.012 5 0.013 5 0.014 1 0.001 1 0.867
其他 Others 0.257 4 0.273 6 0.247 5 0.012 6 0.751

2.4.5 线性判别分析效应大小(LEfSe)

由图5可知,颜色代表对应分组,柱状图的长度代表差异物种的贡献度大小,即为线性判别分析(LDA)值,图中展示了LDA值大于设定值(默认设置为2)的条件下不同组间相对丰度有显著差异的物种(P<0.05)。

2.4.6 Spearman相关性网络与Spearman相关性聚类标记

Spearman相关性检验仅在P<0.05时才能在网络中绘制。本研究在肉牛瘤胃微生物群和重要表型之间建立了Spearman相关性网络(图7)和Spearman相关性聚类标记(图8),经过可视化处理后进行相关分析,结果表明,瘤胃Prevotellaceae_UCG-003相对丰度与DM、NDF、ADF表观消化率呈正相关(P<0.05),WCHB1-41相对丰度与ADF表观消化率呈负相关(P<0.05),Bacteroidales_RF16_group相对丰度与EE表观消化率呈正相关(P<0.05)。
图6 LDA值分布柱状图

Flavobacteriales:黄杆菌目;Fibrobacteraceae:纤维杆菌科;Mailhella:巴氏杆菌属;Selenomonadaceae:新月形单胞菌科;Succinivibrionaceae:琥珀弧菌科;Succinimonas:琥珀酸单胞菌种;Fibrobacterales:纤维杆菌目;Stenotrophomonas:寡养单胞菌;Enterobacteriaceae:肠杆菌科;Elusimicrobiales:迷踪菌目;Parasutterella:副萨特氏菌;Burkholderiales:伯克氏菌目;Sutterellaceae:梭菌科;Elusimicrobium:迷踪菌;Elusimicrobiaceae:迷踪菌科;Fibrobacter:纤维杆菌;Anaerovibrio:厌氧弧菌;Veillonellales_Selenomonadales:韦荣氏球菌目;Enterobacterales:肠杆菌目。

Fig.6 Histogram of LDA value distribution

图7 Spearman相关性网络

黄色实线表示正相关,灰色虚线表示负相关;线宽表示相关强度大小。

Prevotella:普雷沃氏菌属;Rikenellaceae_RC9_gut_group:理研菌科RC9肠道群;Prevotellaceae_UCG-001:普雷沃氏菌科UCG-001;Prevotellaceae_UCG-003:普雷沃氏菌科UCG-003;Bacteroidales_RF16_group:拟杆菌目RF16群;Acinetobacter:不动杆菌属;DM:干物质表观消化率 dry matter apparent digestibility;CP:粗蛋白质表观消化率 crude protein apparent digestibility;EE:粗脂肪表观消化率 ether extract apparent digestibility;NDF:中性洗涤纤维表观消化率 neutral detergent fiber apparent digestibility;ADF:酸性洗涤纤维表观消化率 acid detergent fiber apparent digestibility。下图同 the same as below。

Fig.7 Spearman correlation network

The yellow solid line indicated positive correlation, and gray dashed line indicated negative correlation; the line width indicated the correlation strength size.

图8 Spearman相关性聚类标记

*表示P<0.05,**表示P<0.01。

Fig.8 Spearman correlation cluster marker

* mean P<0.05, and ** mean P<0.01.

3 讨论

3.1 不同粗饲料组合对肉牛生长性能的影响

许多关于动物营养和行为学的研究表明,牧场上肉牛的采食量可能会受到植物特征的调节[14⇓⇓-17]。不同饲料的较高摄入量主要归因于营养平衡[18-19]。味觉在调节牲畜采食方面发挥着重要作用,并有力的支持了多样化饲料的高摄入量[20⇓-22]。本研究中,羊草+玉米秸秆青贮组的采食量最高,原因在于玉米秸秆青贮质地松散并带有酸香酒糟气味,而羊草细长,肉牛采食后咀嚼时间短,并且减少肉牛胃肠道的充盈感。研究表明,当向牲畜提供混合饲料时,他们的饲料摄入量更大,生长性能表现更好[23⇓⇓-26]。此外,根据粗饲料品种的营养价值,与其他2组相比,羊草+玉米秸秆青贮组中较高的CP含量和较低的粗纤维含量可能是肉牛对DMI有所提高的另一个原因。羊草+玉米秸秆青贮组、玉米秸秆+玉米秸秆青贮组的ADG显著高于玉米秸秆组,羊草+玉米秸秆青贮组显著高于玉米秸秆+玉米秸秆青贮组,这首先与羊草+玉米秸秆青贮组的DMI较高呈正相关,由于玉米秸秆青贮后的结构松散,与羊草搭配可以使瘤胃微生物有更大的附着表面积,更容易被降解利用,进一步提高肉牛的生长性能。羊草+玉米秸秆青贮组的F/G显著高于玉米秸秆组,表明对比单一饲喂玉米秸秆,饲喂羊草+玉米秸秆青贮组合有更高的饲料利用率。本试验中,16.7%羊草+33.3%玉米秸秆青贮的粗饲料组合对肉牛生长性能的提高效果最好。

3.2 不同粗饲料组合对肉牛营养物质表观消化率的影响

营养物质表观消化率不仅可以反映反刍动物的消化能力,也是评价生长性能的重要参考指标,受多种因素的影响,如饲粮组成、原料加工方式及采食量等,不同粗饲料来源的营养物质表观消化率会有差异[27⇓-29]。不同的粗饲料组合改变饲料纤维结构,刺激反刍和咀嚼,影响营养物质的消化代谢。DM表观消化率反映了反刍动物对饲粮总体的消化能力,其高低与饲粮中的CP、EE、NDF和ADF等营养成分的消化吸收程度有关[30]。周汉林等[31]研究表明,随着饲粮NDF水平的增加,DM表观消化率随之降低。本试验测得羊草+玉米秸秆青贮组的DM表观消化率最高,其次是玉米秸秆+玉米秸秆青贮组,而玉米秸秆组的DM表观消化率最低,这可能是因为玉米秸秆NDF含量高,而过高的粗纤维含量会降低饲粮在瘤胃的滞留时间,加快食糜在肠道内的移动速度,降低了肉牛对玉米秸秆组中DM表观消化率[32]。在反刍动物的饲粮中,粗纤维的消化水平的对动物机体的生长发育、瘤胃健康和瘤胃内环境的健康具有非常重要的作用[33]。饲粮的品质、纤维利用效果和组合效应与NDF、ADF表观消化率高低密切相关[34-35]。本试验中,羊草+玉米秸秆青贮组的肉牛ADF表观消化率显著高于玉米秸秆组,与孙国强等[36]研究结果一致。这与粗饲料本身的性质有关,粗饲料来源不同的饲粮,其粗纤维含量和消化情况也不同,羊草的可溶性纤维和可消化纤维含量较高,而不易消化纤维含量较低,这有利于瘤胃微生物对饲粮的降解[37]。另外玉米秸秆组的NDF含量高于羊草+玉米秸秆青贮组,NDF的大量摄入会使得食糜在瘤胃内流速加快,这也可能与玉米秸秆组的ADF表观消化率低有关系。

3.3 不同粗饲料组合对肉牛瘤胃发酵参数的影响

瘤胃pH是用于评价瘤胃健康状况和直观反映瘤胃内环境重要指标之一,受到饲料种类、饲粮摄入量高低、唾液的分泌以及有机酸积累等因素共同影响[38]。研究表明,反刍动物瘤胃微生物群落组成、结构及功能均受pH调控[39]。本试验中,3组瘤胃液pH均在6.76~6.83,不影响瘤胃微生物活性和动物生长,较为合理。NH3-N是反刍动物氮代谢的中间产物,是反映氮代谢是否平衡的重要指标。本研究中,3组瘤胃液NH3-N含量在9~12 mg/dL,与相关研究中瘤胃液适宜NH3-N含量(5~25 mg/dL)相符合[40]。羊草+玉米秸秆青贮组的瘤胃液NH3-N含量显著低于玉米秸秆组的原因可能是因为粗饲料组合饲喂肉牛,饲料营养平衡与纤维结构的改善使瘤胃微生物活性有所增加,加速了NH3-N在瘤胃中的降解,更有利于肉牛育肥。瘤胃发酵的改善和NH3-N含量的增加也得益于VFA(乙酸盐、丙酸盐和丁酸盐)的产生和分布[41]。
瘤胃微生物将部分碳水化合物降解为VFA,VFA为机体提供70%~80%可消化能。乙酸、丙酸和丁酸在瘤胃发酵VFA占比很大,也是机体代谢最为重要的几种VFA,同时,VFA为微生物发酵底物提供能量和碳架。异丁酸、戊酸与异戊酸被称为异位酸,可以增加非蛋白氮的利用,促进瘤胃内乙酸的合成[42⇓-44]。羊草+玉米秸秆青贮组中的瘤胃总挥发性脂肪酸含量显著高于其他2组。乙酸和丙酸是饲料在瘤胃内发酵产生的2大主要有机酸,不同种类饲料发酵产生的乙酸/丙酸不同。因此,瘤胃液乙酸/丙酸可反映饲料在瘤胃中的发酵模式。本试验中,羊草+玉米秸秆青贮组的乙酸和丙酸含量显著高于其他2组,但乙酸/丙酸差异不显著,这是因为羊草+玉米秸秆青贮组肉牛DMI高,肉牛每日摄入的CP含量和能量水平较高,饲粮中的非结构性碳水化合物在瘤胃中发酵率很高,提高了瘤胃中乙酸和丙酸含量。本研究表明,不同粗饲料组合可以提高VFA含量,但对乙酸/丙酸影响不显著。

3.4 不同粗饲料组合对肉牛瘤胃微生物区系的影响

瘤胃作为反刍动物重要的消化器官,瘤胃中微生物的相对丰度和组成结构直接影响反刍动物对日饲粮中营养物质的消化、吸收和利用,饲粮组成的不同是影响瘤胃微生物区系的重要因素之一[45]。Chanthakhoun等[46]研究发现,不同种类粗饲料饲喂肉牛可以改变瘤胃菌群。本研究中Venn图显示,3组肉牛瘤胃中有部分微生物菌群是不变的,但是有各自的结构特点。已知细菌群落的多样性和丰富度受到饲料类型的影响[47⇓-49]。本试验中,Alpha多样性指标(Shannon指数和Chao1指数)显示,与玉米秸秆组相比,羊草+玉米秸秆青贮组和玉米秸秆+玉米秸秆青贮组的细菌多样性和丰富度更高,表明不同种类粗饲料组合对肉牛瘤胃微生物组成有直接影响。然而,无论饲粮组成如何,根据先前对反刍动物的研究发现核心微生物组都由Firmicutes、Bacteroidetes和Proteobacteria主导[50⇓⇓-53],这表明这些菌门在反刍动物的瘤胃功能和生态中发挥着重要作用,与本研究的结果一致。Firmicutes的成员在能量利用中发挥重要作用[54],以满足肉牛快速育肥期间的高能量需求。Bacteroidetes的成员主要促进饲粮中蛋白质和碳水化合物的降解,从而促进胃肠道免疫系统的发育[55]。本试验发现,饲喂不同粗饲料中,羊草+玉米秸秆青贮组和玉米秸秆+玉米秸秆青贮组的瘤胃Bacteroidetes相对丰度对比玉米秸秆组有上升的趋势,说明饲粮中添加不同粗饲料组合后采食量的提高和纤维结构的改变,改善了瘤胃内环境,更适合Bacteroidetes的生存。值得注意的是,与其他2组相比,玉米秸秆组的瘤胃Fibrobacterota相对丰度有上升趋势,这是因为玉米秸秆组中NDF、ADF含量高,刺激肉牛瘤胃Fibrobacterota相对丰度的提高,是一种底物诱导效应和微生物间协同作用,这与王荣蛟[56]的试验结果一致。Proteobacteria在瘤胃中也非常重要,虽然其相对丰度远不及Firmicutes和Bacteroidetes,但会影响饲粮中非蛋白氮物质的降解和瘤胃生物膜的形成[57]。3组之间瘤胃Proteobacteria相对丰度差异不显著,但玉米秸秆+玉米秸秆青贮组的瘤胃Proteobacteria相对丰度高于其他2组,这可能是因为肉牛饲喂玉米秸秆+玉米秸秆青贮组合,其瘤胃可以更好地利用饲粮中的可溶性碳水化合物,这与周芳芳[58]研究结果一致。
本试验中,在属水平上,虽然瘤胃Prevotella相对丰度在3组之间无显著差异,但由于其在Bacteroidetes中数量较多,也是瘤胃菌属水平上数量最多的优势菌,在瘤胃代谢中起至关重要的作用。Prevotella能够降解蛋白质、肽类以及淀粉的活性物质[59]。值得注意的是,在属水平上,羊草+玉米秸秆青贮组的瘤胃Prevotellaceae_UCG-003相对丰度显著高于玉米秸秆组,玉米秸秆组和羊草+玉米秸秆青贮组的瘤胃Bacteroidales_RF16_group相对丰度显著高于玉米秸秆+玉米秸秆青贮组。Prevotellaceae_UCG-003和Bacteroidales_RF16_group同属于Bacteroidetes。Bacteroidetes常认为是肠道中的有益菌,具有大量产短链脂肪酸性质和高效的多糖降解系统[60]。本试验中,瘤胃Prevotellaceae_UCG-003相对丰度与DM、NDF、ADF表观消化率呈正相关,Bacteroidales_RF16_group相对丰度与EE表观消化率呈正相关。WCHB1-41属于疣微菌门(Verrucomicrobiota),存在于健康个体的肠黏膜中,具有抗炎作用,同时维持宿主微生物组中的葡萄糖稳态。本试验中,玉米秸秆+玉米秸秆青贮组的瘤胃WCHB1-41相对丰度显著高于其他2组,且瘤胃WCHB1-41相对丰度与ADF表观消化率呈负相关。
在整个研究过程中,肉牛瘤胃微生物区系的组成与瘤胃发酵参数之间存在利用或生产关联。此外,粗饲料类型对瘤胃中的微生物区系和VFA含量有直接影响,越来越多的证据表明,动物的表型性状是由瘤胃微生物驱动的,而瘤胃中VFA含量会影响瘤胃微生物的功能[61⇓-63]。综上所述,这些变化和关系揭示了向肉牛提供不同粗饲料组合相关的重要特征,瘤胃微生物组成和瘤胃发酵参数的变化可能是影响肉牛生长性能的主要因素。

4 结论

羊草+玉米秸秆青贮组合粗饲料的酸酒糟气味促进肉牛采食,纤维结构的改善提高了碳水化合物发酵后VFA含量,VFA含量的提高会降低肉牛瘤胃和肠道pH,改善肉牛瘤胃微生物区系,减少有害菌的相对丰度,进一步促进肉牛生长。本试验中,16.7%羊草+33.3%玉米秸秆青贮的粗饲料组合可使肉牛生长性能达到最佳。

感谢东北农业大学生命科学学院高乐鹏博士对文稿所提的宝贵意见。

References

Publishing order | Descend order by publishing year | Descend order by cited within
[1]
BARRIÈRE Y. Brown-midrib genes in maize and their efficiency in dairy cow feeding.Perspectives for breeding improved silage maize targeting gene modifications in the monolignol and p-hydroxycinnamate pathways[J]. Maydica, 2017, 62(2):1-19.

[2]
CHIBISA G E, BEAUCHEMIN K A. Effects of feeding corn silage from short-season hybrids and extending the backgrounding period on production performance and carcass traits of beef cattle[J]. Journal of Animal Science, 2018, 96(6):2490-2503.

DOI PMID

[3]
TIAN J P, YU Y D, YU Z, et al. Effects of lactic acid bacteria inoculants and cellulase on fermentation quality and in vitro digestibility of Leymus chinensis silage[J]. Grassland Science, 2014, 60(4):199-205.

[4]
BRITO A F, BRODERICK G A. Effect of varying dietary ratios of alfalfa silage to corn silage on production and nitrogen utilization in lactating dairy cows[J]. Journal of Dairy Science, 2006, 89(10):3924-3938.

PMID

[5]
HASSANAT F, GERVAIS R, JULIEN C, et al. Replacing alfalfa silage with corn silage in dairy cow diets:effects on enteric methane production,ruminal fermentation,digestion,N balance,and milk production[J]. Journal of Dairy Science, 2013, 96(7):4553-4567.

[6]
YAN R, CHEN S, ZHANG X, et al. Short communication:effects of replacing part of corn silage and alfalfa hay with Leymus chinensis hay on milk production and composition[J]. Journal of Dairy Science, 2011, 94(7):3605-3608.

[7]
ZEBELI Q, ASCHENBACH J R, TAFAJ M, et al. Invited review:role of physically effective fiber and estimation of dietary fiber adequacy in high-producing dairy cattle[J]. Journal of Dairy Science, 2012, 95(3):1041-1056.

[8]
ZEBELI Q, MANSMANN D, AMETAJ B N, et al. A model to optimise the requirements of lactating dairy cows for physically effective neutral detergent fibre[J]. Archives of Animal Nutrition, 2010, 64(4):265-278.

DOI PMID

[9]
刘公社, 李晓霞, 齐冬梅, 等. 羊草种质资源的评价与利用[J]. 科学通报, 2016, 61(2):271-281.

LIU G S, LI X X, QI D M, et al. Evaluation and utilization of Leymus chinensis germplasm resources[J]. Chinese Science Bulletin, 2016, 61(2):271-281. (in Chinese)

[10]
闫玉春, 唐海萍, 常瑞英, 等. 典型草原群落不同围封时间下植被、土壤差异研究[J]. 干旱区资源与环境, 2008(2):145-151.

YAN Y C, TANG H P, CHANG R Y, et al. Study on the difference of vegetation and soil in typical steppe communities under different fenced time[J]. Journal of Arid Land Resources and Environment, 2008(2):145-151. (in Chinese)

[11]
BERNARD J K, WEST J W, TRAMMELL D S. Effect of replacing corn silage with annual ryegrass silage on nutrient digestibility,intake,and milk yield for lactating dairy cows[J]. Journal of Dairy Science, 2002, 85(9):2277-2282.

[12]
张丽英. 饲料分析及饲料质量检测技术[M]. 4版. 北京: 中国农业大学出版社, 2016.

ZHANG L Y. Feed analysis and feed quality testing technology[M]. 4th ed. Beijing: China Agricultural University Press, 2016. (in Chinese)

[13]
ZHONG R Z, LI J G, GAO Y X, et al. Effects of substitution of different levels of steam-flaked corn for finely ground corn on lactation and digestion in early lactation dairy cows[J]. Journal of Dairy Science, 2008, 91(10):3931-3937.

DOI PMID

[14]
COOPER S D B, KYRIAZAKIS I, OLDHAM J D. The effect of late pregnancy on the diet selections made by ewes[J]. Livestock Production Science, 1994, 40(3):263-275.

[15]
OWEN S N. Foraging responses of kudus to seasonal changes in food resources:elasticity in constraints[J]. Ecology, 1994, 75(4):1050-1062.

[16]
MOLLE G, DECANDIA M, GIOVANETTI V, et al. Responses to condensed tannins of flowering Sulla (Hedysarum coronarium L.) grazed by dairy sheep part 1:effects on feeding behaviour,intake,diet digestibility and performance[J]. Livestock Science, 2009, 123(2/3):138-146.

[17]
VILLALBA J J, PROVENZA F D, CATANESE F, et al. Understanding and manipulating diet choice in grazing animals[J]. Animal Production Science, 2015, 55(3):261-271.

[18]
ADLER L S. Size-mediated performance of a generalist herbivore feeding on mixed diets[J]. Southwestern Naturalist, 2004, 49(2):189-196.

[19]
FREELAND W J, JANZEN D H. Strategies in herbivory by mammals:the role of plant secondary compounds[J]. The American Naturalist, 1974, 108(961):269-289.

[20]
PROVENZA F D. Implications of linking herbivore experience,varied diets,and plant biochemical diversity for pastures[C]// ASA-CSSA-SSSA International Annual Meetings. Salt Lake City: online,2005:254-1.

[21]
PROVENZA F D, SCOTT C B, PHY T S, et al. Preference of sheep for foods varying in flavors and nutrients[J]. Journal of Animal Science, 1996, 74(10):2355-2361.

DOI PMID

[22]
EARLY D M, PROVENZA F D. Food flavor and nutritional characteristics alter dynamics of food preference in lambs[J]. Journal of Animal Science, 1998, 76(3):728-734.

PMID

[23]
PENNINGS S C, NADEAU M T, PAUL V J. Selectivity and growth of the generalist herbivore (Dolabella auricularia) feeding upon complementary resources[J]. Ecology, 1993, 74(3):879-890.

[24]
BERNAYS E A, BRIGHT K L, GONZALEZ N, et al. Dietary mixing in a generalist herbivore:tests of two hypotheses[J]. Ecology, 1994, 75(7):1997-2006.

[25]
BURRITT E A, PROVENZA F D. Role of toxins in intake of varied diets by sheep[J]. Journal of Chemical Ecology, 2000, 26(8):1991-2005.

[26]
MARSH K J, WALLIS I R, MCLEAN S, et al. Conflicting demands on detoxification pathways influence how common brushtail possums choose their diets[J]. Ecology, 2006, 87(8):2103-2112.

PMID

[27]
周瑞, 李耀东, 罗建芬, 等. 西兰花尾菜发酵饲料对绵羊生长性能、营养物质表观消化率及血清生化、抗氧化和免疫指标的影响[J]. 动物营养学报, 2023, 35(10):6497-6506.

DOI

ZHOU R, LI Y D, LUO J F, et al. Effects of broccoli residue fermented feed on growth performance,nutrient apparent digestibility and serum biochemical,antioxidant and immune indexes of sheep[J]. Chinese Journal of Animal Nutrition, 2023, 35(10):6497-6506. (in Chinese)

DOI

[28]
曹祺. 绿原酸对湖羊生长性能、胃肠道组织形态及微生物区系的影响[D]. 硕士学位论文. 郑州: 河南农业大学, 2022.

CAO Q. Effects of chlorogenic acid on growth performance,gastrointestinal tract histomorphology and microbiota of Hu sheep[D]. Master’s Thesis. Zhengzhou: Henan Agricultural University, 2022. (in Chinese)

[29]
陈跃鹏. 全株玉米与玉米秸秆青贮品质评价及对肉牛生长性能和瘤胃微生物区系的影响[D]. 硕士学位论文. 郑州: 河南农业大学, 2018.

CHEN Y P. Quality evaluation of whole plant corn and corn stalk and its effect on the growth performance and rumen microbial community of beef cattle[D]. Master’s Thesis. Zhengzhou: Henan Agricultural University, 2018. (in Chinese)

[30]
张兴隆, 杨永在, 王长水, 等. 精料比例对皖南牛粗饲料采食量和日粮养分表观消化率的影响[J]. 中国畜牧杂志, 2016, 52(1):38-42.

ZHANG X L, YANG Y Z, WANG C S, et al. Effect of concentrate proportion on roughage intake and apparent digestibility of nutrients of Wannan cattle[J]. Chinese Journal of Animal Science, 2016, 52(1):38-42. (in Chinese)

[31]
周汉林, 莫放, 李琼, 等. 日粮中性洗涤纤维水平对中国荷斯坦公牛营养物质消化率的影响[J]. 海南大学学报(自然科学版), 2006, 24(3):275-283.

ZHOU H L, MO F, LI Q, et al. Influence of dietary neutral detergent fiber levels on Chinese Hostein male calves’ digestibility of nutrient substances[J]. Natural Science Journal of Hainan University(Natural Science Edition), 2006, 24(3):275-283. (in Chinese)

[32]
祁茹, 林英庭. 日粮物理有效中性洗涤纤维对奶牛营养调控的研究进展[J]. 粮食与饲料工业, 2010(5):52-55.

QI R, LIN Y T. Research progress of dietary physically available neutral detergent fiber on nutrition regulation of dairy cows[J]. Cereal & Feed Industry, 2010(5):52-55. (in Chinese)

[33]
姜芳, 王佳堃. 日粮纤维对反刍动物瘤胃发酵的影响[J]. 饲料研究, 2009(1):58-60.

JIANG F, WANG J K. Effect of dietary fiber on rumen fermentation in ruminants[J]. Feed Research, 2009(1):58-60. (in Chinese)

[34]
楼灿, 姜成钢, 马涛, 等. 饲养水平对肉用绵羊妊娠期消化代谢的影响[J]. 动物营养学报, 2014, 26(1):134-143.

DOI

LOU C, JIANG C G, MA T, et al. Effects of feeding level on digestion and metabolism of meat Ewes during pregnancy[J]. Chinese Journal of Animal Nutrition, 2014, 26(1):134-143. (in Chinese)

[35]
魏晨, 刘桂芬, 游伟, 等. 6种反刍动物常用粗饲料在肉牛瘤胃中的降解规律比较[J]. 动物营养学报, 2019, 31(4):1666-1675.

WEI C, LIU G F, YOU W, et al. Comparison on degradation rule of six kinds of common roughages for ruminants in rumen of beef cattle[J]. Chinese Journal of Animal Nutrition, 2019, 31(4):1666-1675. (in Chinese)

[36]
孙国强, 吕永艳, 张杰杰. 利用体外瘤胃发酵法研究全株玉米青贮与花生蔓和羊草间的组合效应[J]. 草业学报, 2014, 23(3):224-231.

DOI

SUN G Q, LV Y Y, ZHANG J J. A study on the associative effect of whole corn silage-peanut vine and Leymus chinensis by rumen fermentation in vitro[J]. Acta Prataculturae Sinica, 2014, 23(3):224-231. (in Chinese)

[37]
FIRKINS J L. Effects of feeding nonforage fiber sources on site of fiber digestion[J]. Journal of Dairy Science, 1997, 80(7):1426-1437.

PMID

[38]
HAN Z Q, LI K, SHAHZAD M, et al. Analysis of the intestinal microbial community in healthy and diarrheal perinatal yaks by high-throughput sequencing[J]. Microbial Pathogenesis, 2017,111:60-70.

[39]
DAN X, CHEN H, CHEN F, et al. Analysis of the rumen bacteria and methanogenic archaea of yak (Bos grunniens) steers grazing on the Qinghai-Tibetan plateau[J]. Livestock Science, 2016,188:61-71.

[40]
MCDONALD P, EDWARDS R A. The influence of conservation methods on digestion and utilization of forages by ruminants[J]. The Proceedings of the Nutrition Society, 1976, 35(2):201-211.

[41]
DONG L F, ZHANG W B, ZHANG N F, et al. Feeding different dietary protein to energy ratios to Holstein heifers:effects on growth performance,blood metabolites and rumen fermentation parameters[J]. Journal of Animal Physiology and Animal Nutrition, 2017, 101(1):30-37.

[42]
ROMAN G Y, DENTON B L, MITCHELL K E, et al. Conditions stimulating neutral detergent fiber degradation by dosing branched-chain volatile fatty acids.Ⅰ:comparison with branched-chain amino acids and forage source in ruminal batch cultures[J]. Journal of Dairy Science, 2021, 104(6):6739-6755.

[43]
FELIX A, COOK R M, HUBER J T. Effect of feeding isoacids with urea on growth and nutrient utilization by lactating cows[J]. Journal of Dairy Science, 1980, 63(11):1943-1946.

PMID

[44]
FELIX A, COOK R M, HUBER J T. Isoacids and Urea as a protein supplement for lactating cows fed corn silage[J]. Journal of Dairy Science, 1980, 63(7):1098-1103.

[45]
李世歌, 陈光吉, 李小冬, 等. 杂交构树青贮对务川白山羊瘤胃微生物区系的影响[J]. 中国饲料, 2022(1):114-120.

LI S G, CHEN G J, LI X D, et al. Effects of hybrid Broussonetia papyrifera silage on rumen microflora of Wuchuan white goat[J]. China Feed, 2022(1):114-120. (in Chinese)

[46]
CHANTHAKHOUN V, WANAPAT M, KONGMUN P, et al. Comparison of ruminal fermentation characteristics and microbial population in swamp buffalo and cattle[J]. Livestock Science, 2012, 143(2/3):172-176.

[47]
JOSHUA C, MCCAN N. High-throughput methods redefine the rumen microbiome and its relationship with nutrition and metabolism[J]. Bioinformatics and Biology Insights, 2014,8:109-125.

[48]
HENDERSON G, COX F, GANESH S, et al. Rumen microbial community composition varies with diet and host,but a core microbiome is found across a wide geographical range[J]. Scientific Reports, 2015,5:14567.

[49]
ZHANG J, SHI H T, WANG Y J, et al. Effect of dietary forage to concentrate ratios on dynamic profile changes and interactions of ruminal microbiota and metabolites in Holstein heifers[J]. Frontiers in Microbiology, 2017,8:2206.

[50]
CHEN Y B, LAN D L, TANG C, et al. Effect of DNA extraction methods on the apparent structure of yak rumen microbial communities as revealed by 16S rDNA sequencing[J]. Polish Journal of Microbiology, 2015, 64(1):29-36.

[51]
GUO W, LI Y, WANG L Z, et al. Evaluation of composition and individual variability of rumen microbiota in yaks by 16S rRNA high-throughput sequencing technology[J]. Anaerobe, 2015,34:74-79.

[52]
LENG J, XIE L J, ZHU R J, et al. Dominant bacterial communities in the rumen of gayals (Bos frontalis),yaks (Bos grunniens) and Yunnan yellow cattle (Bos taurs) revealed by denaturing gradient gel electrophoresis[J]. Molecular Biology Reports, 2011, 38(8):4863-4872.

[53]
ZHOU Z M, FANG L, MENG Q X, et al. Assessment of ruminal bacterial and archaeal community structure in yak (Bos grunniens)[J]. Frontiers in Microbiology, 2017,8:179.

[54]
WU S R, CHEN X D, LI J L, et al. Effect of alfalfa hay and starter feed supplementation on caecal microbiota and fermentation,growth,and health of yak calves[J]. Animal, 2021, 15(3):100019.

[55]
JIANG F, GAO H M, QIN W, et al. Marked seasonal variation in structure and function of gut microbiota in forest and alpine musk deer[J]. Frontiers in Microbiology, 2021,12:699797.

[56]
王荣蛟. 不同质量粗饲料与精粗比日粮对奶水牛消化与瘤胃微生物的影响[D]. 硕士学位论文. 昆明: 云南农业大学, 2022.

WANG R J. Effects of different quality roughages and concentrate to roughage rations on nutrient digestion and rumen microorganisms in dairy buffaloes[D]. Master’s Thesis. Kunming: Yunnan Agricultural University, 2022. (in Chinese)

[57]
PITTA D W, PINCHAK W E, INDUGU N, et al. Metagenomic analysis of the rumen microbiome of steers with wheat-induced frothy bloat[J]. Frontiers in Microbiology, 2016,7:689.

[58]
周芳芳. 不同粗饲料来源饲粮对荷斯坦奶公犊生长性能、养分消化及瘤胃细菌区系的影响[D]. 硕士学位论文. 南宁: 广西大学, 2020.

ZHOU F F. Effects of different roughage sources on growth performence,nutrient digestibility and rumen bacterial flora of Holstein calves[D]. Master’s Thesis. Nanning: Guangxi University, 2020. (in Chinese)

[59]
肖俊楠. 不同粗饲料对西门塔尔杂交牛生产性能、肉品质及瘤胃微生物区系的影响[D]. 硕士学位论文. 郑州: 河南农业大学, 2019.

XIAO J N. Effects of different roughage on production performance,meat quality and rumen microflora of Simmental crossbred cattle[D]. Master’s Thesis. Zhengzhou: Henan Agricultural University, 2019. (in Chinese)

[60]
刘昭曦, 王禄山, 陈敏. 肠道菌群多糖利用及代谢[J]. 微生物学报, 2021, 61(7):1816-1828.

LIU Z X, WANG L S, CHEN M. Glycan utilization and metabolism by gut microbiota[J]. Acta Microbiologica Sinica, 2021, 61(7):1816-1828. (in Chinese)

[61]
MAO S Y, HUO W J, ZHU W Y. Microbiome-metabolome analysis reveals unhealthy alterations in the composition and metabolism of ruminal microbiota with increasing dietary grain in a goat model[J]. Environmental Microbiology, 2016, 18(2):525-541.

[62]
MORGAVI D P, RATHAHAO-PARIS E, POPOVA M, et al. Rumen microbial communities influence metabolic phenotypes in lambs[J]. Frontiers in Microbiology, 2015,6:1060.

[63]
SCHÄREN M, FRAHM J, KERSTEN S, et al. Interrelations between the rumen microbiota and production,behavioral,rumen fermentation,metabolic,and immunological attributes of dairy cows[J]. Journal of Dairy Science, 2018, 101(5):4615-4637.

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