研究论文

苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能、血清生化指标及瘤胃发酵参数、组织形态和微生物区系的影响

  • 周亚楠 ,
  • 冯宇哲 ,
  • 杨得玉 ,
  • 刘书杰 ,
  • 崔占鸿 , *
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  • 青海大学畜牧兽医科学院,农业农村部青藏高原放牧牦牛藏羊动物营养与饲草料重点实验室,青海省牦牛工程技术研究中心,青海省高原放牧家畜动物营养与饲料科学重点实验室,西宁 810016
* 崔占鸿,副研究员,硕士生导师,E-mail:

周亚楠(1997—),女,河南项城人,硕士研究生,动物营养与饲料科学专业。E-mail:

Copy editor: 武海龙

收稿日期: 2022-07-27

  网络出版日期: 2023-02-13

基金资助

国家自然科学基金项目(32260853)

青海省自然科学基金面上项目(2020-ZJ-911)

Effects of Alfalfa Hay, Oat Hay and Their Mixed Feeding on Growth Performance, Serum Biochemical Indexes and Rumen Fermentation Parameters, Morphology and Microflora of Suckling Yak Calves

  • ZHOU Yanan ,
  • FENG Yuzhe ,
  • YANG Deyu ,
  • LIU Shujie ,
  • CUI Zhanhong , *
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  • Key Laboratory of Plateau Grazing Animal Nutrition and Feed Science of Qinghai Province,Yak Engineering Technology Research Center of Qinghing Province, Ministry of Agriculture and Rural Affairs Key Laboratory of Animal Nutrition and Forage-Feed of Grazing Yak and Tibetan Sheep in Qinghai-Tibetan Plateau, Qinghai University College of Animal Husbandry and Veterinary Sciences, Xining 810016, China
* associate professor, E-mail:

Received date: 2022-07-27

  Online published: 2023-02-13

摘要

本试验旨在探究苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能、血清生化指标及瘤胃发酵参数、组织形态和微生物区系的影响。选取21只体重[(36.47±0.99) kg]相近、健康的45日龄牦牛公犊牛,采用随机区组设计分为3组,每组7头牛。各组在代乳粉和开食料的基础上饲喂粗饲料,苜蓿干草组(AH组)饲喂苜蓿干草,燕麦干草组(OH组)饲喂燕麦干草,苜蓿干草+燕麦干草组(AO组)饲喂苜蓿干草+燕麦干草(苜蓿草干∶燕麦干草=1∶1),3组的粗精比均7∶3(粗饲料∶开食料)。预试期21 d,正试期120 d。结果表明:1)AO组的终末体重、瘤胃重显著高于AH组和OH组(P<0.05),AH组和OH组的料重比显著高于AO组(P<0.05)。2)AO组和AH组的血清白蛋白含量显著高于OH组(P<0.05),AO组的血清肌酐含量显著高于AH组和OH组(P<0.05)。3)AO组的瘤胃乙酸、丁酸、总挥发性脂肪酸含量和乙酸/丙酸极显著高于AH组和OH组(P<0.01),AO组的瘤胃氨态氮含量显著高于OH组(P<0.05)。4)AO组的瘤胃肌层厚度、黏膜上皮厚度、黏膜下层厚度、乳头高度、乳头宽度和浆膜层厚度显著或极显著高于AH组和OH组(P<0.05或P<0.01)。5)在门水平上,AO组和OH组的瘤胃拟杆菌门、光古菌门相对丰度显著高于AH组(P<0.05)。在属水平上,AO组和OH组的瘤胃欧鲁森氏菌属相对丰度显著高于AH组(P<0.05),AO组的瘤胃普雷沃氏菌属、克里斯滕森菌科R-7群、甲烷短杆菌属和普雷沃氏菌科-UCG-001相对丰度显著或极显著高于AH组和OH组(P<0.05或P<0.01),AH组和OH组的瘤胃梭菌属UCG-014相对丰度显著高于AO组(P<0.05)。综上所述,采用饲喂代乳粉方式培育哺乳期牦牛犊牛,在开食料的基础上同时饲喂苜蓿干草和燕麦干草提高了牦牛犊牛体重,改变了瘤胃微生物菌群多样性及相对丰度,正向调控了瘤胃形态和功能的发育,为青藏高原地区牦牛犊牛在粗饲料组合饲粮的应用提供了重要参考。

本文引用格式

周亚楠 , 冯宇哲 , 杨得玉 , 刘书杰 , 崔占鸿 . 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能、血清生化指标及瘤胃发酵参数、组织形态和微生物区系的影响[J]. 动物营养学报, 2023 , 35(2) : 995 -1007 . DOI: 10.12418/CJAN2023.095

Abstract

The aim of this experiment was to investigate the effects of alfalfa hay, oat hay and their mixed feeding on growth performance, serum biochemical indexes and rumen fermentation parameters, morphology and microflora of suckling yak calves. Twenty-one healthy 45-day-old yak calves (male) with similar body weight [(36.47±0.99) kg] were randomly assigned into three groups with seven calves per group according a random block design. On the basis of milk replacer and starter, each group was fed with roughages, alfalfa hay group (AH group) was fed with alfalfa hay, oat hay group (OH group) was fed with oat hay, and alfalfa hay+oat hay group (AO group) was fed with alfalfa hay+oat hay (alfalfa hay∶oat hay = 1∶1). The ratio of roughage to concentrate was 7∶3 (roughage∶starter). The pre-experimental period lasted for 21 days, and the experimental period lasted for 120 days. The results showed as follows: 1) the final body weight and rumen weight of AO group were significantly higher than those of AH group and OH groups (P<0.05), and the feed to gain ration of AH group and OH group was significantly higher than that of AO group (P<0.05). 2) The serum albumin content of AO group and AH group was significantly higher than that of OH group (P<0.05), and the serum creatinine content of AO group was significantly higher than that of AH group and OH group (P<0.05). 3) The contents of acetic acid, butyric acid, total volatile fatty acid and acetic acid/propionic acid in rumen of AO group were significantly higher than those of AH group and OH group (P<0.01), and the rumen ammonia nitrogen content of AO group was significantly higher than that of OH group (P<0.05). 4) The muscle layer thickness, mucosal epithelium thickness, submucous layer thickness, papillary height, papillary width and plasma membrane thickness in rumen of AO group were significantly higher than those of AH group and OH group (P<0.05 or P<0.01). 5) At phylum level, the relative abundances of Bacteroidota and Euryarchaeota in rumen of AO group and OH group were significantly higher than those of AH group (P<0.05). At genus level, the rumen Olsenella relative abundance of AO group and OH group was significantly higher than that of AH group (P<0.05), the relative abundances of Prevotella, Christensenellaceae_R-7_group, Methanobrevibacter and Prevodiaceae_UCG-001 in rumen of AO group were significantly higher than those of AH group and OH group (P<0.05 or P<0.01), and the rumen Clostridium_UCG-014 relative abundance of AH group and OH groups was significantly higher than that of AO group (P<0.05). In summary, suckling yak calves bred by feeding milk replacer, feeding alfalfa hay and oat hay at the same time on the basis of starter increase the body weight of yak calves, change the diversity and relative abundance of rumen microflora, and positively regulate the development of rumen morphology and function, which provided an important reference for the application of yak calves in roughage combination diet in Qinghai-Tibet Plateau.

在成年反刍动物的瘤胃内栖息着大量微生物,致使瘤胃内环境变得较为复杂[1]。因此,对于反刍动物而言,瘤胃微生物极其重要,而对于哺乳期反刍动物,瘤胃微生物区系在未反刍之前就已建立[2],但不完善。随着瘤胃的不断发育,对粗纤维的消化会逐渐增强[3];随后,瘤胃微生物在反刍动物成长过程会随着饲粮转换逐步形成和建立完善的微生物区系[4],幼龄反刍动物为了适应环境和饲粮的变化也会随之调整优势菌群[5]。在哺乳期给犊牛饲喂开食料的同时添加粗饲料,能够促进瘤胃快速发育,缩短犊牛断奶时间。不同来源的粗饲料所含的营养物质也有所差异,因此,不同来源的粗饲料对哺乳期反刍动物的影响是不同的[6]。尤其是瘤胃微生物主要由饲料的结构决定[7],故在反刍动物幼龄期饲喂不同的粗饲料必定会影响反刍动物瘤胃细菌群落的丰富性[8]。对于反刍动物,瘤胃的发育极其关键,瘤胃微生物主要的作用是促进瘤胃发育并通过分泌各种酶来降解饲粮中的粗饲料[9-10],从而进一步调控反刍动物机体的生长发育[11]
在青藏高原传统的饲养管理模式下,冷季时天然牧草的质量急剧降低,严重限制了犊牛的营养摄入水平,从而导致放牧幼畜掉膘甚至成为僵牛。为了提高牦牛犊牛的生长性能,改善饲粮营养结构,本研究选用苜蓿干草替代青海地方性资源中禾本科的燕麦干草;而苜蓿干草属于典型的豆科牧草,营养物质含量丰富,能够提高反刍动物的免疫能力。因此,本试验旨在研究苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能、血清生化指标及瘤胃发酵参数、组织形态和微生物区系的影响[12],探讨苜蓿干草作为牦牛犊牛粗饲料的可行性,以期为青藏高原地区哺乳期牦牛犊牛饲粮营养结构与科学配制提供参考依据。

1 材料与方法

1.1 试验设计

选取21只体重[(36.47±0.99) kg]相近、健康的45日龄牦牛公犊牛,采用随机区组设计分为3组,每组7头牛。各组在代乳粉和开食料的基础上饲喂粗饲料,苜蓿干草组(AH组)饲喂苜蓿干草,燕麦干草组(OH组)饲喂燕麦干草,苜蓿干草+燕麦干草组(AO组)饲喂苜蓿干草+燕麦干草(苜蓿草干∶燕麦干草=1∶1),3组的粗精比均7∶3(粗饲料∶开食料)。预试期21 d,正试期120 d。

1.2 试验饲粮

3组的代乳粉、开食料和干草饲喂量一致,代乳粉和开食料来自北京标准动物营养研究中心,苜蓿干草来自甘肃省张掖市,燕麦干草来自青海省海晏县。开食料组成见表1,代乳粉、开食料、苜蓿干草和燕麦干草营养水平见表2
表1 开食料组成(干物质基础)

Table 1 Composition of the starter (DM basis)%

原料 Ingredients 含量 Content
玉米 Corn 46.5
豆粕 Soybean meal 27.0
麸皮 Bran 9.5
膨化大豆 Expanded soybean 8.0
乳清粉 Dried whey powder 5.0
细石粉 Fine limestone 1.6
预混料 Premix1) 1.0
脂肪粉 Fat powder 0.5
磷酸氢钙 CaHPO4 0.5
食盐 NaCl 0.4
合计 Total 100.0

预混料为每千克开食料提供 The premix provided the following per kg of the starter:Fe 22.1 mg,Mn 9.82 mg,Cu 2.25 mg,Zn 27.0 mg,Se 0.19 mg,I 0.54 mg,Co 0.09 mg,VA 30 000 IU,VD 30 000 IU,VE 4 000 IU。

表2 代乳粉、开食料、苜蓿干草和燕麦干草营养水平

Table 2 Nutrient levels of milk replacer, starter, alfalfa hay and oat hay

营养水平
Nutrient levels
代乳粉
Milk replacer
开食料
Starter
燕麦干草
Oat hay
苜蓿干草
Alfalfa hay
干物质 DM/% 95.00 87.90 93.00 95.00
粗蛋白质 CP/% DM 26.24 20.00 4.08 14.19
粗脂肪 EE/% DM 27.79 4.70 4.20 3.39
中性洗涤纤维 NDF/% DM 10.90 84.40 64.86
酸性洗涤纤维 ADF/% DM 4.10 45.18 46.13
钙 Ca/% DM 2.50 0.80 1.05 1.55
磷 P/% DM 1.40 0.45 0.15 0.74
钙/磷 Ca/P 1.79 1.78 7.00 2.10

1.3 饲养管理

试验时间2021年8—12月,饲养试验于青海省海北州海晏县高原现代生态畜牧业科技试验示范园进行。牦牛犊牛单栏饲养,预试期代乳粉早、中、晚(08:30、12:30、16:30)各饲喂1次,正试期代乳粉早、晚(08:30、16:30)各饲喂1次。在预试期前1周内,为减少犊牛应激,将牦牛奶与代乳粉按比例使用奶瓶饲喂,代乳粉比例从20%逐渐增大至100%,需将冲泡代乳粉的沸水冷却至42 ℃,代乳粉与水按1∶5比例配制。正式试验开始后,代乳粉添加量为0.48 kg/d,每隔7 d增加15 g;粗饲料添加量为140 g/d,每隔7 d增加70 g;开食料添加量为70 g/d,每隔7 d增加30 g。为了模拟哺乳环境,代乳粉遵循代乳粉饲养标准,在每个阶段的规定摄入量内不限制其摄入。为了保证每头牦牛犊牛开食料摄入量一致,先饲喂开食料后饲喂粗饲料,待粗饲料和开食料摄入量达到1 kg时进行断奶并屠宰。

1.4 样品采集和指标测定

1.4.1 生长性能测定

试验开始和结束时称量牦牛犊牛体重,记录耗料量,计算初始体重、终末体重、干物质采食量、平均日增重和料重比;屠宰前1天,测量牦牛犊牛体高、体斜长、管围、胸围。

1.4.2 样品采集

牦牛犊牛于屠宰前1天16:00后断食断水,翌日清晨使用采血针从牦牛犊牛颈静脉采血至肝素钠采血管,采集3管,每管5 mL,静置后置于离心机中4 000 r/min离心10 min,取上层血清置于冻存管中,于-80 ℃保存待测,采血后进行称重、屠宰。
在瘤胃内部取瘤胃液,用4层纱布过滤后应当立即测定pH,之后分装在离心管内立即投入液氮进行保存,用于后续瘤胃发酵参数测定和16S rRNA高通量测序。取瘤胃腹囊组织块约2 cm×2 cm,用0.9%生理盐水洗净后存放于4%的多聚甲醛溶液,用于后续制备石蜡切片进行组织形态学观察。

1.4.3 血清生化指标测定

血清样品送至青海省第一人民医院进行检测,采用全自动生化分析仪,测定指标为白蛋白(albumin,ALB)、球蛋白(globulin,GLB)、碱性磷酸酶(alkaline phosphatase,ALP)、丙氨酸氨基转移酶(alanine aminotransferase,ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase,AST)、肌酐(creatinine,CRE)、总蛋白(total protein,TP)。

1.4.4 瘤胃发酵指标测定

氨态氮(NH3-N)含量采用比色法[13],使用TU-1810紫外可见分光光度计进行测定。微生物蛋白(microbial proteins,MCP)含量采用考马斯亮蓝法[14],使用分光光度计进行测定。挥发性脂肪酸(volatile fatty acids,VFA)含量采用气相色谱仪(GC-2014,日本岛津公司)进行测定[15],气相色谱条件为:载气为氮气(N2),分流比为40∶1,进样量为1 μL,进样孔温度为250 ℃,辅助箱温度为250 ℃,气化室温度为250 ℃,火焰离子化检测器(FID)温度为250 ℃,色谱柱型号为AT-FFAP毛细管填充柱(30.0 m×0.32 μm)。恒流模式,流量2.1 mL/min,平均线速度38 cm/s,柱压11.3 psi(0.1 mPa)。

1.4.5 瘤胃组织形态测定

采用苏木精-伊红(HE)染色法制备石蜡切片后在Olympus BX53电子显微镜下观察并测量瘤胃腹囊的黏膜上皮厚度、黏膜下层厚度、乳头宽度、乳头高度、肌层厚度以及浆膜层厚度。

1.4.6 瘤胃微生物区系测定

将1管5 mL的瘤胃液样品在干冰条件下储存运输至北京诺和致源生物技术公司,在Illumina MiSeq平台上对瘤胃液的细菌扩增子进行测序。文库构建使用的试剂盒是TruSeq® DNA PCR-Free Sample Preparation Kit。一般流程为样品准备、DNA提取与检测、PCR扩增、产物纯化、文库制备及库检、NovaSeq上机检测。使用通用引物V341F(5’-CCTAYGGGRBGCASCAG-3’)和V806R(5’-GGACTACHVGGGTWTCTAAT-3’)对微生物基因组总DNA的16S rRNA V3~V4高变区进行PCR扩增,经检验合格后进行上机测序。得到的下机数据经过对各样本的数据进行均一化处理,进行Alpha多样性分析和Beta多样性分析。

1.5 数据处理与统计分析

试验原始数据经Excel 2016初步整理后,再经SPSS 20.0软件的ANOVA程序进行单因素方差分析和Duncan氏法多重比较。结果以平均值±标准差表示,P>0.05表示差异不显著,P<0.05表示差异显著,P<0.01表示差异极显著。

2 结果

2.1 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能和体尺指标的影响

表3可知,3组之间初始体重、体斜长、体高、胸围、管围、干物质采食量和平均日增重均差异不显著(P>0.05)。AO组的终末体重、瘤胃重显著高于AH组和OH组(P<0.05),AH组和OH组的料重比显著高于AO组(P<0.05)。
表3 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能和体尺指标的影响

Table 3 Effects of alfalfa hay, oat hay and their mixed feeding on growth performance and body size indexes of suckling yak calves

项目
Items
组别 Groups P
P-value
AH OH AO
初始体重 Initial body weight/kg 36.00±1.58 35.80±0.84 37.60±0.55 0.053
终末体重 Final body weight/kg 71.20±1.79b 70.60±0.55b 74.80±3.11a 0.017
平均日增重 Average daily gain/(g/d) 293.33±3.12 290.00±3.12 310.00±10.00 0.095
料重比 Feed/gain 2.68±0.03a 2.69±0.01a 2.55±0.05b 0.018
体斜长 Body length/cm 92.00±1.30 90.40±0.51 92.60±1.69 0.470
体高 Body height/cm 88.60±1.44 89.80±0.80 92.40±1.44 0.135
胸围 Chest circumference/cm 112.80±0.80 111.80±2.13 113.20±1.67 0.824
管围 Cannon circumference/cm 15.60±0.24 15.80±0.20 16.20±0.20 0.178
瘤胃重 Rumen weight/kg 0.86±0.01b 0.85±0.01b 0.96±0.04a 0.049
干物质采食量 Dry matter intake/(kg/d) 1.00 1.00 1.00 1.000

同行数据肩标不同小写字母表示差异显著(P<0.05),不同大写字母表示差异极显著(P<0.01),相同小写字母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), and with different capital letter superscripts mean significant difference (P<0.01), while with the same small letter or no letter superscripts mean no significant difference (P>0.05). The same as below.

2.2 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛血清生化指标的影响

表4可知,3组之间血清ALP、ALT、AST活性和GLB、TP含量均差异不显著(P>0.05)。AO组和AH组的血清ALB含量显著高于OH组(P<0.05),AO组的血清CRE含量显著高于AH组和OH组(P<0.05)。
表4 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛血清生化指标的影响

Table 4 Effects of alfalfa hay, oat hay and their mixed feeding on serum biochemical indexes of suckling yak calves

项目
Items
组别 Groups P
P-value
AH OH AO
白蛋白 ALB/(g/L) 29.10±0.32a 26.18±1.21b 29.62±0.64a 0.033
球蛋白 GLB/(g/L) 43.86±1.32 42.80±2.47 48.65±3.62 0.283
总蛋白 TP/(g/L) 72.96±1.25 68.98±2.06 75.27±2.84 0.663
碱性磷酸酶 ALP/(U/L) 4.00±0.91 3.50±0.50 4.75±0.68 0.634
丙氨酸氨基转移酶 ALT/(U/L) 37.90±1.67 32.92±2.93 39.97±2.62 0.181
天门冬氨酸氨基转移酶 AST/(U/L) 88.36±4.06 87.00±2.28 89.74±2.84 0.910
肌酐 CRE/(μmol/L) 116.00±1.53b 114.33±1.86b 135.67±4.33a 0.042

2.3 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃发酵参数的影响

表5可知,3组之间瘤胃MCP、丙酸含量均差异不显著(P>0.05)。AO组的瘤胃乙酸、丁酸、总挥发性脂肪酸(TVFA)含量和乙酸/丙酸极显著高于AH组和OH组(P<0.01),AO组的瘤胃NH3-N含量显著高于OH组(P<0.05)。
表5 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃发酵参数的影响

Table 5 Effects of alfalfa hay, oat hay and their mixed feeding on rumen fermentation parameters of suckling yak calves

项目
Items
组别 Groups P
P-value
AH OH AO
pH 7.04±0.07a 6.69±0.25b 6.92±0.01a 0.015
氨态氮 NH3-N/(mg/dL) 1.86±0.23ab 1.36±0.19b 2.18±0.06a 0.021
微生物蛋白 MCP/(mg/dL) 13.15±2.06 15.98±0.77 17.60±1.63 0.181
乙酸 Acetate/(mmol/L) 22.28±1.52Bb 24.28±0.81Bb 33.58±0.81Aa <0.001
丙酸 Propionate/(mmol/L) 6.01±0.26 5.99±0.24 7.23±0.75 0.169
丁酸 Butyrate/(mmol/L) 3.43±0.14Bb 3.43±0.15Bb 4.51±0.12Aa 0.001
总挥发性脂肪酸 TVFA/(mmol/L) 43.13±0.96Bb 38.86±1.14Bb 52.14±3.13Aa 0.003
乙酸/丙酸 Acetate/propionate 3.54±0.08Bb 3.82±0.59Bb 4.86±0.48Aa 0.005

2.4 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃组织形态的影响

图1表6可知,AO组的瘤胃肌层厚度显著高于AH组和OH组(P<0.05),AO组的瘤胃黏膜上皮厚度、黏膜下层厚度、乳头高度、乳头宽度和浆膜层厚度极显著高于AH组和OH组(P<0.01)。
图1 哺乳期牦牛犊牛的瘤胃冷冻切片

A:黏膜上皮 mucosal epithelium;B:黏膜肌层 mucosal muscle layer;C:黏膜下层submucous layer;D:肌层 muscular layer;E:浆膜 plasma membrane。

Fig.1 Frozen section of rumen of suckling yak calves (400×)

表6 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃组织形态的影响

Table 6 Effects of alfalfa hay, oat hay and their mixed feeding on rumen morphology of suckling yak calvesμm

项目
Items
组别 Groups P
P-value
AH OH AO
黏膜上皮厚度 Mucosal epithelium thickness 91.70±4.04Bb 78.46±1.06Bb 189.83±18.98Aa 0.005
黏膜下层厚度 Submucous layer thickness 746.74±66.48Bb 724.54±56.73Bb 1 275.19±73.37Aa 0.007
乳头宽度 Papillary width 1 152.57±52.71B 612.47±41.94C 1 392.12±39.25A 0.009
乳头高度 Papillary height 605.03±20.74Bb 547.99±47.72Bb 1 816.09±72.94Aa <0.001
肌层厚度 Muscular layer thickness 1 985.63±80.92b 1 299.89±84.40c 2 284.27±65.07a 0.025
浆膜层厚度 Plasma membrane thickness 117.80±7.96B 85.30±3.00C 135.44±3.40A 0.002

2.5 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃微生物区系的影响

2.5.1 操作分类单元(OTU)聚类及基础分析结果

样品经高通量测序后,统计分析得到每个样品的OUT数目和代表序列。本试验共15个样品,以97%的一致性将样品聚类成OTU,数据处理后平均每个样品测得80 493条原始序列,质控后每个样品平均57 345条有效序列,质控有效率为71.29%。

2.5.2 Venn图

图2可知,AH组、OH组和AO组的OTU数目分别为2 599、2 537、2 914个,3组相同的OTU数目为679个,AH组、OH组和AO组特有的OTU数目分别为1 174、1 260、1 093个。
图2 Venn图

RSA代表苜蓿干草组,RSO代表燕麦干草组,RSAO代表苜蓿干草+燕麦干草组。下图同。

Fig.2 Venn diagram

RSA represented the AH group, RSO represented the OH group, and RSAO represented the AO group. The same as below.

2.5.3 Alpha多样性指数

表7图3可知,3组覆盖率均为1.00,测序深度已经是饱和状态,说明测序结果可代表样品中微生物的真实信息。AO组的OTU数目显著高于AH组和OH组(P<0.05)。3组之间的Chao1指数、覆盖率、Shannon指数、Simpson指数均无显著差(P>0.05)。
表7 哺乳期牦牛犊牛瘤胃微生物OTU数目和Alpha多样性指数分析

Table 7 Analysis of rumen microbial OTU number and alpha diversity indexes of suckling yak calves

项目
Items
组别 Groups P
P-value
AH OH AO
Chao1指数 Chao1 842.33±28.56 799.66±29.31 915.64±51.81 0.338
覆盖率 Good’s coverage 1.00±0.00 1.00±0.00 1.00±0.00 1.000
操作分类单元 OTU 840.68±27.83b 707.67±29.67b 1 024.00±39.00a 0.011
Shannon 指数 Shannon index 8.02±0.30 7.78±0.31 7.90±0.24 0.837
Simpson 指数 Simpson index 0.98±0.00 0.97±0.10 0.99±0.00 0.726
图3 覆盖率图

Fig.3 Good’s coverage diagram

2.5.4 瘤胃微生物优势菌门和菌属相对丰度

表8可知,在门水平上,3组瘤胃微生物优势菌门均为厚壁菌门、拟杆菌门,AO组和OH组的瘤胃拟杆菌门、光古菌门相对丰度显著高于AH组(P<0.05)。在属水平上,AO组和OH组的瘤胃欧鲁森氏菌属相对丰度显著高于AH组(P<0.05),AO组的瘤胃普雷沃氏菌属、克里斯滕森菌科R-7群、甲烷短杆菌属相对丰度显著高于AH组和OH组(P<0.05),AO组的瘤胃普雷沃氏菌科UCG-001相对丰度极显著高于AH组和OH组(P<0.01),AH和OH组的瘤胃梭菌属UCG-014相对丰度显著高于AO组(P<0.05)。
表8 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃微生物优势菌门和菌属相对丰度的影响

Table 8 Effects of alfalfa hay, oat hay and their mixed feeding on relative abundance of rumen microbial dominant phylum and genus of suckling yak calves%

项目
Items
组别 Groups P
P-value
AH OH AO
门水平 Phylum level
厚壁菌门 Firmicutes 54.88±6.96 39.59±2.19 38.88±4.94 0.121
拟杆菌门 Bacteroidota 21.65±1.35b 42.65±3.04a 46.83±2.31a 0.020
放线菌门 Actinobacteriota 0.39±0.14 0.98±0.13 3.56±2.42 0.407
光古菌门 Euryarchaeota 2.69±1.11b 5.18±0.16a 6.69±0.87a 0.036
变形菌门 Proteobacteria 2.06±0.66 2.47±0.47 0.69±0.09 0.100
髌骨细菌门 Patescibacteria 0.67±0.06 0.18±0.04 1.08±0.67 0.263
属水平 Genus level
欧鲁森氏菌属 Olsenella 0.17±0.04b 0.30±0.09a 0.62±0.18a 0.028
奎因氏菌属 Quinella 1.14±0.71 0.83±0.70 0.55±0.22 0.713
理研菌科RC9肠道群Rikenellaceae_RC9_gut_group 18.91±3.90 20.74±1.68 21.84±1.32 0.679
普雷沃氏菌属 Prevotella 7.71±0.85b 7.71±2.23b 17.06±0.45a 0.016
F082 2.76±0.93 6.09±1.11 7.37±2.78 0.298
克里斯滕森菌科R-7群 Christensenellaceae_R-7_group 4.71±0.61b 4.38±0.14b 7.48±1.45a 0.032
产粪甾醇真细菌群
Eubacterium_coprostanoligenes_group
2.96±0.90 3.18±0.89 2.23±0.57 0.631
甲烷短杆菌属 Methanobrevibacter 2.58±1.11b 4.47±0.26b 6.34±0.79a 0.044
普雷沃氏菌科UCG-001 Prevotellaceae_UCG-001 0.72±0.22Bb 1.02±0.08Bb 8.98±0.41Aa <0.001
梭菌属UCG-014 Clostridium_UCG-014 3.94±0.44a 2.45±0.72a 1.28±0.47b 0.046

3 讨论

3.1 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛生长性能的影响

犊牛在哺乳期的营养对后续发育极为重要,尤其在发育后期,摄入的饲粮将使瘤胃快速发育[16]。在哺乳期给犊牛饲喂粗饲料,饲粮中的粗纤维能够促进瘤胃发育,增强对粗饲料的消化,加大采食量[3,17-19]。研究表明,粗饲料来源不同,犊牛的采食量、生长发育也不同[20-21]。研究表明,犊牛饲喂燕麦干草和苜蓿干草组合相较于单独饲喂苜蓿干草,其发育及消化更好[22]。本试验中,3组干物质采食量相同,这与Daneshvar等[23]和Thomas等[24]研究发现不同粗饲料来源饲粮不影响反刍动物的干物质采食量的结果一致;3组的体尺指标差异不显著,这与周芳芳[25]研究发现粗饲料对犊牛体尺影响不显著的结果一致;AO组的终末体重显著高于AH组和OH组,说明在补饲开食料基础上饲喂混合干草可以有效增加哺乳期犊牛的体重,这与任春燕等[26]研究发现粗饲料能够促进犊牛发育的结果一致;AO组的瘤胃重显著高于AH组和OH组,这与崔利宏等[27]研究发现混合干草更能够促进犊牛发育以及Tamate等[28]研究发现粗饲料能够促进反刍动物前胃发育的结果一致。因此,饲喂混合干草相较于单一干草而言更能促进哺乳期牦牛犊牛发育。

3.2 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛血清生化指标的影响

血清生化指标是动物生长过程中健康和营养物质消化吸收状况的直接反映[29-31]。其中TP由ALB、GLB构成,三者可以反映动物机体对营养物质的代谢情况[32],能够反映蛋白质合成与分解速率,并维持血管内的平衡[33],还能够提高机体的免疫力;ALP、ALT、AST等是肝脏功能的直接反映,可以监测肝脏是否被损伤;CRE则能够反映机体摄入的营养状况,监测动物的肾脏功能是否正常[32]。本研究无论饲喂单一干草还是混合干草,ALP、ALT和AST活性以及GLB和TP含量均差异不显著,表明饲喂的干草未损伤犊牛肝脏,饲喂混合干草在哺乳期犊牛生长期间是可行的,能够给犊牛提供均衡的营养,这与赵淑敏等[34]、周明等[35]、周亚楠等[36]的研究结果一致。本研究发现,在开食料的基础上对哺乳期牦牛犊牛饲喂不同的干草能对血清ALB、CRE含量造成一定的影响,AO组和AH组的血清ALB含量显著高于OH组,AO组的血清CRE含量显著高于AH组和OH组,说明饲喂组合干草相较于单一干草更能加强哺乳期牦牛犊牛对蛋白质合成和分解以及增强肾脏功能,促进机体代谢,进而提高饲料转化率。

3.3 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃发酵指标的影响

反刍动物摄入粗饲料后,瘤胃内微生物的菌群活动会改变,瘤胃液pH也会随之改变[37],反刍动物摄入粗饲料后,瘤胃内环境的改变可能会影响其正常的生长发育,通过瘤胃液pH能直观地表现瘤胃健康状态[27],并综合反映瘤胃微生物活动以及生成VFA情况[38]。通常情况下,反刍动物瘤胃液的pH在6.0~7.5[28],本试验瘤胃液pH为6.69~7.04,表明本研究的3组瘤胃发酵均处于正常水平。有研究显示,适合瘤胃内消化粗饲料的纤维素分解菌生存的pH应在6.2~6.8[1],本研究的瘤胃液pH在这一区间内,说明3组的瘤胃内环境适合微生物生存。VFA是反刍动物瘤胃发酵最为重要的物质,通过瘤胃吸收后为机体提供了总能量需要的60%~70%[39]。本研究中,AO组的瘤胃TVFA、乙酸、丙酸含量高于另AH组和OH组,说明饲喂组合干草能促进哺乳期牦牛犊牛瘤胃发酵,所含的饲粮营养成分更利于乙酸和丙酸生成。蛋白质和脂肪含量较高的粗饲料能够促进TVFA的生成,而OH组的蛋白质和脂肪含量较低,故其瘤胃TVFA含量较低。瘤胃微生物所需的氮主要来自NH3-N[40]。本研究中,AO组的牦牛瘤胃NH3-N含量最高,OH组最低,说明饲喂组合干草能促进瘤胃微生物对NH3-N的利用,这与Pazoki等[41]研究结果一致;3组的瘤胃MCP含量差异不显著,说明饲喂不同粗饲料对MCP的合成影响较小或者无影响,这与Van Dung等[42]研究结果一致。

3.4 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃组织形态的影响

哺乳期是犊牛瘤胃发育重要阶段,研究表明摄入粗饲料能促进犊牛瘤胃发育,使其重量快速增加,组织形态发育完全,在空腹体重时所占比例增大[43]。瘤胃能有效地帮助反刍动物将饲粮进行均匀的搅拌和揉搓,吸收VFA后通过糖异生环节为动物提供能量来源。动物摄入粗饲料后,一方面经瘤胃发酵产生乙酸、丙酸等被反刍动物吸收;另一方面则可以刺激瘤胃乳头发育[44]。本研究中,AO组的瘤胃乳头宽度、乳头高度发育较好,说明饲喂组合干草相较于单一干草更能够有效促进哺乳期牦牛犊牛瘤胃乳头的发育。瘤胃肌层能够使瘤胃产生胃蠕动,进而产生反刍行为。本试验中,AO组的瘤胃肌层和浆膜层发育相比于其他2组要好,同样表明饲喂组合干草相较于单一干草能刺激瘤胃肌层发育并促进瘤胃进行反刍行为[28,45-46]。因此,从上述结果来看,饲喂组合干草的牦牛犊牛瘤胃发育最好。

3.5 苜蓿干草、燕麦干草及二者混合饲喂对哺乳期牦牛犊牛瘤胃微生物区系的影响

反刍动物摄入粗饲料后,瘤胃微生物能够将其进行发酵,产生机体生长发育所需的营养,并保证瘤胃的健康发育。但在摄入粗饲料的同时,也要考虑瘤胃内环境随之变化后能否适应瘤胃微生物生存,因为在一定范围内瘤胃微生物会随摄入的饲粮而发生改变,从而保持瘤胃内环境的稳定性。因此,从微生物角度研究粗饲料对瘤胃的变化,对于前期瘤胃发酵指标的结果更能准确、科学进行解释。而Chanthakhoun等[47]在水牛饲养中发现,添加不同的粗饲料可以改变瘤胃菌群的相对丰度。本研究中,AO组的瘤胃OTU数目显著高于AH组和OH组,与上述研究结果一致。
在门水平上,大量研究表明,反刍动物瘤胃菌群中相对丰度最高的是厚壁菌门和拟杆菌门[48-50],本研究得出了一致的结果。研究发现,厚壁菌门参与碳水化合物的分解与代谢[51],拟杆菌门主要分解瘤胃中非纤维素[52],如能够将饲粮中的可溶性多糖降解为琥珀酸,并在瘤胃内经过脱羧反应快速产生丙酸[53]。AO组瘤胃拟杆菌门和光古菌门相对丰度显著高于AH组,可能是因为AO组饲粮中粗纤维含量比AH组高。
在属水平上,本研究中AO组的瘤胃普雷沃氏菌属、普雷沃氏菌科UCG-003、克里斯滕森菌科R-7群和甲烷短杆菌属相对丰度显著高于AH组和OH组。Tian等[15]研究发现,粗饲料来源不同,营养成分不同,瘤胃普雷沃氏菌属、普雷沃氏菌科UCG-003相对丰度会有差异,这与本试验结果一致。普雷沃氏菌属是反刍动物瘤胃拟杆菌门中最丰富的一个属,其相对丰度在成年反刍动物瘤胃中保持相对的稳定性,它主要受到饲粮组成和营养水平的影响。Jami等[50]研究发现,草饲牛瘤胃普雷沃氏菌属相对丰度较高,与本试验研究结果一致。本研究中,AO组的瘤胃克里斯滕森菌科R-7群和甲烷短杆菌属相对丰度显著高于AH组和OH组,克里斯滕森菌科R-7群能调节瘤胃健康,甲烷短杆菌属能够提高瘤胃内纤维素酶活性,说明饲喂组合干草相较于饲喂单一干草更能增加反刍动物对纤维的利用率。AH组和OH组的瘤胃梭菌_UCG-014相对丰度高于AO组,可能是由于AH组饲粮蛋白质含量高于AO组或者OH组饲粮纤维含量略高于AO组,具体影响因素需要后续的深度挖掘。因此,饲喂苜蓿干草和燕麦干草组合,提高了瘤胃微生物的整体相对丰度,说明哺乳期牦牛犊牛饲喂组合干草的效果最好。

4 结论

综上所述,采用饲喂代乳粉方式培育哺乳期牦牛犊牛,在开食料的基础上同时饲喂苜蓿干草和燕麦干草提高了牦牛犊牛体重,改变了瘤胃微生物菌群多样性及相对丰度,正向调控了瘤胃形态和功能的发育,为青藏高原地区牦牛犊牛在粗饲料组合饲粮的应用提供了重要参考。
[1]
冯仰廉. 反刍动物营养学[M]. 北京: 科学出版社, 2004.

FENG Y L. Nutrition of ruminants[M]. Beijing: Science Press, 2004. (in Chinese)

[2]
JIAO J Z, LI X P, BEAUCHEMIN K A, et al. Rumen development process in goats as affected by supplemental feeding v. grazing:age-related anatomic development,functional achievement and microbial colonisation[J]. British Journal of Nutrition, 2015, 113(6):888-900.

DOI

[3]
KHAN M A, BACH A, WEARY D M, et al. Invited review:transitioning from milk to solid feed in dairy heifers[J]. Journal of Dairy Science, 2016, 99(2):885-902.

DOI

[4]
BROWN L D, LASSITER C A, EVERETT J P, et al. Effect of protein level in calf starters on the growth rate and metabolism of young calves[J]. Journal of Dairy Science, 1958, 41(10):1425-1433.

DOI

[5]
DIAS J, MARCONDES M I, NORONHA M F, et al. Effect of pre-weaning diet on the ruminal archaeal,bacterial,and fungal communities of dairy calves[J]. Frontiers in Microbiology, 2017, 8:1553.

DOI

[6]
CASTELLS L, BACH A, ARAUJO G, et al. Effect of different forage sources on performance and feeding behavior of Holstein calves[J]. Journal of Dairy Science, 2012, 95(1):286-293.

DOI PMID

[7]
MORINE S J, DREWNOSKI M E, JOHNSON A K, et al. Determining the influence of dietary roughage concentration and source on ruminal parameters related to sulfur toxicity[J]. Journal of Animal Science, 2014, 92(9):4068-4076.

DOI PMID

[8]
KONG Y H, TEATHER R, FORSTER R. Composition,spatial distribution,and diversity of the bacterial communities in the rumen of cows fed different forages[J]. FEMS Microbiology Ecology, 2010, 74(3):612-622.

DOI

[9]
PURUSHE J, FOUTS D E, MORRISON M, et al. Comparative genome analysis of Prevotella ruminicola and Prevotella bryantii:insights into their environmental niche[J]. Microbial Ecology, 2010, 60(4):721-729.

DOI

[10]
WOOD T M, WILSON C A, STEWART C S. Preparation of the cellulase from the cellulolytic anaerobic rumen bacterium Ruminococcus albus and its release from the bacterial cell wall[J]. Biochemical Journal, 1982, 205(1):129-137.

DOI

[11]
QADIS A Q, GOYA S, IKUTA K, et al. Effects of a bacteria-based probiotic on ruminal pH,volatile fatty acids and bacterial flora of Holstein calves[J]. The Journal of Veterinary Medical Science, 2014, 76(6):877-885.

DOI

[12]
REY M, ENJALBERT F, COMBES S, et al. Establishment of ruminal bacterial community in dairy calves from birth to weaning is sequential[J]. Journal of Applied Microbiology, 2014, 116(2):245-257.

DOI PMID

[13]
BRODERICK G A, KANG J H. Automated simultaneous determination of ammonia and total amino acids in ruminal fluid and in vitro media[J]. Journal of Dairy Science, 1980, 63(1):64-75.

DOI

[14]
WANG M Z, WANG H R, CAO H C, et al. Effects of limiting amino acids on rumen fermentation and microbial community in vitro[J]. Agricultural Sciences in China, 2008, 7(12):1524-1531.

DOI

[15]
TIAN K, LIU J H, SUN Y W, et al. Effects of dietary supplementation of inulin on rumen fermentation and bacterial microbiota,inflammatory response and growth performance in finishing beef steers fed high or low-concentrate diet[J]. Animal Feed Science and Technology, 2019, 258:114299.

DOI

[16]
NEMATI M, AMANLOU H, KHORVASH M, et al. Rumen fermentation,blood metabolites,and growth performance of calves during transition from liquid to solid feed:effects of dietary level and particle size of alfalfa hay[J]. Journal of Dairy Science, 2015, 98(10):7131-7141.

DOI

[17]
MONTORO C, MILLER-CUSHON E K, DEVRIES T J, et al. Effect of physical form of forage on performance,feeding behavior,and digestibility of Holstein calves[J]. Journal of Dairy Science, 2013, 96(2):1117-1124.

DOI

[18]
SALARY NEYA A, FATHI NASRI M H, FARHANGFAR H, et al. Effect of two different levels of fiber on feed intake,average daily gain,feed efficiency and ruminal metabolites of Holstein calves[J]. Iranian Journal of Animal Science Research, 2013, 4(4):323-334.

[19]
CASTELLS L, BACH L, ARIS A, et al. Effects of forage provision to young calves on rumen fermentation and development of the gastrointestinal tract[J]. Journal of Dairy Science, 2013, 96(8):5226-5236.

DOI PMID

[20]
寇占英, 莫放, 李启鹏, 等. 哺乳犊牛消化道主要消化酶活性变化规律研究[C]// 动物营养研究进展——全国畜禽饲养标准学术讨论会暨营养研究会成立大会论文集. 北京: 中国农业出版社, 2000:159-163.

KOU Z Y, MO F, LI Q P, et al. Study on the changes of activities of main digestive enzymes in digestive tract of lactating calves[C]// Animal Nutrition Research Progress—Proceedings of the National Symposium on Livestock and Poultry feeding Standards and the Establishment of the Nutrition Research Association. Beijing: China Agriculture Press, 2000:159-163. (in Chinese)

[21]
BEIRANVAND H, GHORBANI G R, KHORVASH M, et al. Interactions of alfalfa hay and sodium propionate on dairy calf performance and rumen development[J]. Journal of Dairy Science, 2014, 97(4):2270-2280.

DOI PMID

[22]
邹新平. 不同日粮组合对断奶犊牛瘤胃发酵、营养物质消化率及生长发育的影响[D]. 硕士学位论文. 晋中: 山西农业大学, 2015.

ZOU X P. Effects of feed combination on ruminal fermentation,nutrients digestibility,and growth performance,of weaned calves[D]. Master’s Thesis. Jinzhong: Shanxi Agricultural University, 2015. (in Chinese)

[23]
DANESHVAR D, KHORVASH M, GHASEMI E, et al. The effect of restricted milk feeding through conventional or step-down methods with or without forage provision in starter feed on performance of Holstein bull calves[J]. Journal of Animal Science, 2015, 93(8):3979-3989.

DOI PMID

[24]
THOMAS D B, HINKS C E. The effect of changing the physical form of roughage on the performance of the early-weaned calf[J]. Animal Science, 1982, 35(3):375-384.

DOI

[25]
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)

[26]
任春燕, 毕研亮, 杜汉昌, 等. 开食料中不同NDF水平对犊牛生长性能、瘤胃内环境及血清生化指标的影响[J]. 草业学报, 2018, 27(5):210-218.

REN C Y, BI Y L, DU H C, et al. Effects of different starter NDF levels on the growth performance,rumen environments and serum biochemical parameters of calves[J]. Acta Prataculturae Sinica, 2018, 27(5):210-218. (in Chinese)

[27]
崔利宏, 于彦, 王斯琴塔娜, 等. 不同品质粗饲料对断奶至7月龄犊牛生长发育及营养物质消化率的影响[J]. 中国畜牧兽医, 2008, 35(9):9-11.

CUI L H, YU Y, WANG S Q T N, et al. Effect of different forages quality on nutrient digestibility and growth in calves weaning to 7-month-old[J]. China Animal Husbandry & Veterinary Medicine, 2008, 35(9):9-11. (in Chinese)

[28]
TAMATE H, MCGILLIARD A D, JACOBSON N L, et al. Effect of various dietaries on the anatomical development of the stomach in the calf[J]. Journal of Dairy Science, 1962, 45(3):408-420.

DOI

[29]
吴易雄. 家禽血液生化指标与生产性能的关系研究综述[J]. 贵州畜牧兽医, 2002, 26(3):12-13.

WU Y X. Summary on biochemical indexes and productive performances poultry blood[J]. Guizhou Journal of Animal Husbandry & Veterinary Medicine, 2002, 26(3):12-13. (in Chinese)

[30]
SUDRE K, CASSAR-MALEK I, LISTRAT A, et al. Biochemical and transcriptomic analyses of two bovine skeletal muscles in Charolais bulls divergently selected for muscle growth[J]. Meat Science, 2005, 70(2):267-277.

DOI PMID

[31]
NKRUMAH J D, SHERMAN E L, LI C, et al. Primary genome scan to identify putative quantitative trait loci for feedlot growth rate,feed intake,and feed efficiency of beef cattle[J]. Journal of Animal Science, 2007, 85(12):3170-3181.

DOI

[32]
贾泽统. 苜蓿与燕麦干草不同配比对奶牛生产性能的影响[D]. 硕士学位论文. 郑州: 河南农业大学, 2018.

JIA Z T. Effects of different proportion of alfalfa and oat hay on production performance of dairy cows[D]. Master’s Thesis. Zhengzhou: Henan Agricultural University, 2018. (in Chinese)

[33]
王建红, 刁其玉, 许先查, 等. 日粮Lys、Met和Thr添加模式对0-2月龄犊牛生长性能、消化代谢与血清学生化指标的影响[J]. 中国农业科学, 2011, 44(9):1898-1907.

WANG J H, DIAO Q Y, XU X C, et al. Effects of dietary addition pattern of lysine,methionine and threonine in the diet on growth performance,nutrient digestion and metabolism,and serum biochemical parameters in calves at the ages of 0 to 2 months[J]. Scientia Agricultura Sinica, 2011, 44(9):1898-1907. (in Chinese)

[34]
赵淑敏, 苏莹莹, 贾泽统, 等. 燕麦干草和苜蓿干草的组合效应及其对奶牛生产性能、乳品质、血清生化指标和营养物质表观消化率的影响[J]. 动物营养学报, 2021, 33(11):6572-6583.

ZHAO S M, SU Y Y, JIA Z T, et al. Combined effects of oat hay and alfalfa hay and their effects on performance,milk quality,serum biochemical indexes and nutrient apparent digestibility of dairy cows[J]. Chinese Journal of Animal Nutrition, 2021, 33(11):6572-6583. (in Chinese)

[35]
周明, 王恩典, 汪炳红, 等. 不同饲粮组成对西门塔尔杂交牛生长性能和血清生化指标的影响[J]. 粮食与饲料工业, 2016(3):56-59.

ZHOU M, WANG E D, WANG B H, et al. Effects of different diets on growth performance and serum biochemical parameters of Simmental crossbred cattle[J]. Cereal & Feed Industry, 2016(3):56-59. (in Chinese)

[36]
周亚楠, 夏洪泽, 刘书杰, 等. 不同CBI日粮对牦牛瘤胃发酵参数、血清生化指标和养分消化率的影响[J]. 草地学报, 2022, 30(8):2217-2222.

DOI

ZHOU Y N, XIA H Z, LIU S J, et al. Effects of different CBI diets on rumen fermentation parameters,serum biochemical indices and nutrient digestibility of yak[J]. Acta Agrestia Sinica, 2022, 30(8):2217-2222. (in Chinese)

[37]
王坤. 粗饲料来源及长度对水牛犊牛生长性能和瘤胃细菌菌群区系的影响[D]. 硕士学位论文. 南宁: 广西大学, 2020.

WANG K. Effect of source and length of roughage on growth performance and rumen bacterial flora of buffalo calves[D]. Master’s Thesis. Nanning: Guangxi University, 2020. (in Chinese)

[38]
SUN H Z, WANG D M, WANG B, et al. Metabolomics of four biofluids from dairy cows:potential biomarkers for milk production and quality[J]. Journal of Proteome Research, 2015, 14(2):1287-1298.

DOI

[39]
SUÁREZ B J, VAN REENEN C G, GERRITS W J J, et al. Effects of supplementing concentrates differing in carbohydrate composition in veal calf diets:Ⅱ.Rumen development[J]. Journal of Dairy Science, 2006, 89(11):4376-4386.

DOI

[40]
SRINIVAS B, GUPTA B N. Rumen fermentation,bacterial and total volatile fatty acid (TVFA) production rates in cattle fed on urea-molasses-mineral block licks supplement[J]. Animal Feed Science and Technology, 1997, 65(1/2/3/4):275-286.

DOI

[41]
PAZOKI A, GHORBANI G R, KARGAR S, et al. Growth performance,nutrient digestibility,ruminal fermentation,and rumen development of calves during transition from liquid to solid feed:effects of physical form of starter feed and forage provision[J]. Animal Feed Science and Technology, 2017, 234:173-185.

DOI

[42]
VAN DUNG D, SHANG W W, YAO W. Effect of crude protein levels in concentrate and concentrate levels in diet on in vitro fermentation[J]. Asian-Australasian Journal of Animal Sciences, 2014, 27(6):797-805.

DOI

[43]
BAILEY C B. Growth of digestive organs and their contents in Holstein steers:relation to body weight and diet[J]. Canadian Journal of Animal Science, 1986, 66(3):653-661.

DOI

[44]
KASAOKA S, SAKATA Y, SHIMADA M. Effects of coal carbonization conditions on rate of steam gasification of char[J]. Fuel, 1987, 66(5):697-701.

DOI

[45]
HODGSON J. The development of solid food intake in calves.1.The effect of previous experience of solid food,and the physical form of the diet,on the development of food intake after weaning[J]. Animal Science, 1971, 13(1):15-24.

DOI

[46]
PHILLIPS C J C. The effects of forage provision and group size on the behavior of calves[J]. Journal of Dairy Science, 2004, 87(5):1380-1388.

PMID

[47]
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.

DOI

[48]
SHANKS O C, KELTY C A, ARCHIBEQUE S, et al. Community structures of fecal bacteria in cattle from different animal feeding operations[J]. Applied and Environmental Microbiology, 2011, 77(9):2992-3001.

DOI PMID

[49]
HONG P Y, WHEELER E, CANN I K O, et al. Phylogenetic analysis of the fecal microbial community in herbivorous land and marine iguanas of the Galápagos islands using 16S rRNA-based pyrosequencing[J]. The ISME Journal, 2011, 5(9):1461-1470.

DOI

[50]
JAMI E, MIZRAHI I. Similarity of the ruminal bacteria across individual lactating cows[J]. Anaerobe, 2012, 18(3):338-343.

DOI PMID

[51]
HOOK S E, STEELE M A, NORTHWOOD K S, et al. Impact of subacute ruminal acidosis (SARA) adaptation and recovery on the density and diversity of bacteria in the rumen of dairy cows[J]. FEMS Microbiology Ecology, 2011, 78(2):275-284.

DOI PMID

[52]
徐俊. 不同牧草来源的NDF在瘤胃中降解特性及其对细菌群落结构的影响[D]. 博士学位论文. 扬州: 扬州大学, 2014.

XU J. Degradation characteristics of NDF from different forage sources in rumen and its effect on bacterial community structure[D]. Ph.D.Thesis. Yangzhou: Yangzhou University, 2014. (in Chinese)

[53]
POWER S E, O’TOOLE P W, STANTON C, et al. Intestinal microbiota,diet and health[J]. British Journal of Nutrition, 2014, 111(3):387-402.

DOI

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