低蛋白日粮添加过瘤胃蛋氨酸对人工瘤胃和体外后肠道营养代谢的影响
发布时间：2020-11-13 00:18
相比于反刍动物日粮蛋白质含量,蛋白质的品质在生长、生产和繁殖中起着更重要的作用。提高高产奶牛的日粮蛋白含量并不意味着可提高动物生产性能和十二指肠限制氨基酸(AA)的平衡,反而会提高动物尿液和粪便的氮(N)排泄。到达后肠的蛋白质主要以胱氨酸的形式,蛋氨酸的形式非常缺乏,被称为第一限制性AA。日粮中添加过瘤胃形式的限制性AA被认为有利于动物的生理功能:生产性能,生理和繁殖性能等。为此,我们提出研究假设:到达小肠的第一限制性AA为蛋氨酸。这些蛋氨酸来自瘤胃未降解的蛋白,微生物蛋白(MCP)和补充的过瘤胃蛋白(RPMet)。低蛋白日粮添加RPMet不仅降低了饲料成本,而且可改善营养代谢,提高N和能量利用。试验分为4组:(1)高蛋白组(HP,163.39 g/kg),(2)低蛋白组(LP,146.33 g/kg);(3)低蛋白+低浓度RPMet组(LPLMet,141.80 g CP+0.11 g RPMet/kg DM);(4)低蛋白质+高浓度RPMet(LPHMet;143.30 g+0.81g RPMet/kg DM)。其中HP日粮作为阳性对照,低LP组作为阴性对照。依次采用人工瘤胃(Rusitec,15 d适应和7d采样)、皱胃和回肠体外消化(8 d)技术评定消化率。试验结果表明,LPLMet和LPHMet组的Rusitec和后肠道CP体外消化率显著上升。然而,饲料NDF和GE在Rusitec的消化率中无变化,但LPHMet组的后肠道NDF消化率显著高于HP组。此外,RPMet提高了16S r RNA基因的丰度,但对种类无影响。对纤维降解菌R.flavefaciens和F.succinogenes相对丰度无影响,但改变了R.albus。然而,MCP产量、总短链脂肪酸浓度和R.albus相对丰度在LPHMet与HP组无显著差异。HP组的总气体和甲烷产量以及NH3-N浓度显著高于LP、LPLMet和LPHMet组。Rusitec发酵罐在进食前后的p H没有显著变化。与其他组相比,LPHMet组回肠(小肠)液体部分的总AA流量无差异,但蛋氨酸流量显著增加。HP组固体残留物中的总AA和一些必需和非必需的AA明显高于其他组。综上,在低蛋白日粮中补充RPMet(0.11 g/kg DM)对后肠道的大多研究指标无影响。低蛋白日粮中补充高水平RPMet(0.81 g/kg DM),可显著提高MCP、短链脂肪酸浓度、NDF和GE体外消化率、人工瘤胃R.albus丰度。HP组的总气体和甲烷产量显著高于其他组。LPHMet组的后肠道NDF消化率显著高于其他组。HP组固体残留物中的总AA和一些必需和非必需的AA明显高于其他组。从目前的研究可得出结论:低蛋白日粮添加过瘤胃蛋氨酸可显著提高回肠中总氨基酸,必需氨基酸和蛋氨酸的流量,此日粮可替代中产奶牛的高蛋白质日粮。
【学位单位】：西北农林科技大学
【学位级别】：博士
【学位年份】：2018
【中图分类】：S816
【文章目录】：
ABSTRACT
摘要
CHAPTER 1: INTRODUCTION
1.1 Problems due to feeding excessive protein ration in dairy ruminants
1.2 Crude protein, rumen degradable, undegradable and metabolizable protein
1.3 Studies of rumen-protected methionine supplementation and crude protein
1.4 Problems statements, methionine role and hypothesis of the proposed research
1.5 Hypothesis and objectives of the proposed research
CHAPTER 2: REVIEW OF THE LITERATURE
2.1 Introduction of the methionine and biosynthesis process
2.2 The impacts of methionine supplementation on dairy ruminants
2.3 Description of current experimental product
2.4 Characteristics of Rusitec technique and structure of apparatus
2.5 Operation and preparation for running the Rusitec apparatus
2.6 Inoculation of ruminal microbes, incubation process and adaptation period
2.7 Fermenters volume, dilution rate, ration amount and feedbags size
2.8 Parameters reported in the literature during operation of the Rusitec
CHAPTER 3: LOW DIETARY PROTEIN DIET WITH SUPPLEMENTATION OF RUMEN PROTECTED METHIONINE: THEIR EFFECTS ON APPARENT NUTRIENTSDISAPPEARANCE
3.1 Abstract
3.2 Introduction
3.3 Hypothesis and objective
3.4 Material and methods
3.4.1 Animal care
3.4.2 Experimental strategy
3.4.3 Test product description
3.4.4 Experimental diets and inoculum donors
3.4.5 Rumen simulation technique and sampling
3.4.6 In vitro abomasum digestibility, collection of small intestinal fluid of goatsand lyophilization technique
3.4.7 In vitro ileum digestibility technique, and laboratory analyses of feed andsamples
3.5 Statistical analyses
3.6 Results
3.6.1 Effects of supplementation of rumen-protected methionine on disappearanceat Rusitec
3.6.2 Rumen-protected methionine supplements their post-ruminal effects on thedisappearance
3.7 Discussion
3.8 Conclusion
CHAPTER 4: TOTAL POPULATION AND THREE CELLULOLYTIC SPECIFIC SPECIES RESPONSES TO RUMEN PROTECTED METHIONINE WITH LOW DIETARYPROTEIN DIET USING RUSITEC FERMENTERS
4.1 Abstract
4.2 Introduction
4.3 Hypothesis and objective
4.4 Material and methods
4.4.1 Experimental treatments and methodology
4.4.2 Sterilization preparation
4.4.3 The reagents preparation
4.4.4 DNA extraction protocol for rumen microbes
4.4.5 Agar gel electrophoresis
4.4.6 Spectrophotometry test
4.4.7 Quantitative real-time PCR （qrt PCR）
4.4.8 qrt PCR and determination of the bacterial copy number
4.5 Statistical analyses
4.6 Results
4.6.1 Effects of supplements on total and cellulolytic species gene copy of liquidfraction
4.6.2 Effects of supplements on total and cellulolytic species gene copy of solidfraction
4.7 Discussion
4.8 Conclusion
CHAPTER 5: ADDITION OF DIFFERENT LEVELS OF RUMEN PROTECTED METHIONINE WITH LOW PROTEIN DIET: THEIR EFFECTS ON RUMEN ANDPOST- RUMEN FERMENTATION CHARACTERISTICS
5.1 Abstract
5.2 Introduction
5.3 Hypothesis and objective
5.4 Material and methods
5.5 Statistical analyses
5.6 Results
5.6.1 Effects of supplements with low CP on total and individual volatile fattyacids at Rusitec
5.6.2 Post-ruminal effects of supplements with low CP on total and individualvolatile fatty acids
5.6.3 Effects of supplements on total and greenhouse gases production
5.6.4 Rumen p H, microbial protein synthesis, and NH3-N production ruminal andpost-ruminal
5.7 Discussion
5.8 Conclusion
CHAPTER 6: ADDITION OF DIFFERENT LEVELS OF RUMEN PROTECTED METHIONINE AS A CONCEIVABLE APPROACH TO DEPLOYING MAXIMUMTOTAL AND METHIONINE AMINO ACID FLOW AT THE SMALL INTESTINE
6.1 Abstract
6.2 Introduction
6.3 Hypothesis and objective
6.4 Material and Methods
6.4.1 Experimental methodology and treatments
6.4.2 Laboratory analyses of experimental feed and collected samples
6.4.3 The methodology of preparation of Rusitec and in vitro fluid samples foramino acids analyses
6.4.4 The methodology of preparation of Rusitec and in vitro residue samples foramino acids analyses
6.4.5 Sample filtration and constant volume preparation for the amino acidanalyzer
6.5 Statistical analyses
6.6 Results
6.6.1 Low protein with RPMet supplementation their effects on EAA, NEAA andMet flow from the rumen to ileum residue
6.6.2 Low protein with RPMet supplementation their effects on EAA, NEAA andMet flow from rumen to ileum fluid
6.7 Discussion
6.8 Conclusion
CHAPTER 7: Conclusion and Recommendations
7.1 Conclusion
7.2 Recommendations
PUBLICATIONS
ACKNOWLEDGEMENTS
REFERENCES
APPENDIXA
ABBREVIATIONS
BIOGRAPHICAL SKETCH
本文编号：2881447
【学位单位】：西北农林科技大学
【学位级别】：博士
【学位年份】：2018
【中图分类】：S816
【文章目录】：
ABSTRACT
摘要
CHAPTER 1: INTRODUCTION
1.1 Problems due to feeding excessive protein ration in dairy ruminants
1.2 Crude protein, rumen degradable, undegradable and metabolizable protein
1.3 Studies of rumen-protected methionine supplementation and crude protein
1.4 Problems statements, methionine role and hypothesis of the proposed research
1.5 Hypothesis and objectives of the proposed research
CHAPTER 2: REVIEW OF THE LITERATURE
2.1 Introduction of the methionine and biosynthesis process
2.2 The impacts of methionine supplementation on dairy ruminants
2.3 Description of current experimental product
2.4 Characteristics of Rusitec technique and structure of apparatus
2.5 Operation and preparation for running the Rusitec apparatus
2.6 Inoculation of ruminal microbes, incubation process and adaptation period
2.7 Fermenters volume, dilution rate, ration amount and feedbags size
2.8 Parameters reported in the literature during operation of the Rusitec
CHAPTER 3: LOW DIETARY PROTEIN DIET WITH SUPPLEMENTATION OF RUMEN PROTECTED METHIONINE: THEIR EFFECTS ON APPARENT NUTRIENTSDISAPPEARANCE
3.1 Abstract
3.2 Introduction
3.3 Hypothesis and objective
3.4 Material and methods
3.4.1 Animal care
3.4.2 Experimental strategy
3.4.3 Test product description
3.4.4 Experimental diets and inoculum donors
3.4.5 Rumen simulation technique and sampling
3.4.6 In vitro abomasum digestibility, collection of small intestinal fluid of goatsand lyophilization technique
3.4.7 In vitro ileum digestibility technique, and laboratory analyses of feed andsamples
3.5 Statistical analyses
3.6 Results
3.6.1 Effects of supplementation of rumen-protected methionine on disappearanceat Rusitec
3.6.2 Rumen-protected methionine supplements their post-ruminal effects on thedisappearance
3.7 Discussion
3.8 Conclusion
CHAPTER 4: TOTAL POPULATION AND THREE CELLULOLYTIC SPECIFIC SPECIES RESPONSES TO RUMEN PROTECTED METHIONINE WITH LOW DIETARYPROTEIN DIET USING RUSITEC FERMENTERS
4.1 Abstract
4.2 Introduction
4.3 Hypothesis and objective
4.4 Material and methods
4.4.1 Experimental treatments and methodology
4.4.2 Sterilization preparation
4.4.3 The reagents preparation
4.4.4 DNA extraction protocol for rumen microbes
4.4.5 Agar gel electrophoresis
4.4.6 Spectrophotometry test
4.4.7 Quantitative real-time PCR （qrt PCR）
4.4.8 qrt PCR and determination of the bacterial copy number
4.5 Statistical analyses
4.6 Results
4.6.1 Effects of supplements on total and cellulolytic species gene copy of liquidfraction
4.6.2 Effects of supplements on total and cellulolytic species gene copy of solidfraction
4.7 Discussion
4.8 Conclusion
CHAPTER 5: ADDITION OF DIFFERENT LEVELS OF RUMEN PROTECTED METHIONINE WITH LOW PROTEIN DIET: THEIR EFFECTS ON RUMEN ANDPOST- RUMEN FERMENTATION CHARACTERISTICS
5.1 Abstract
5.2 Introduction
5.3 Hypothesis and objective
5.4 Material and methods
5.5 Statistical analyses
5.6 Results
5.6.1 Effects of supplements with low CP on total and individual volatile fattyacids at Rusitec
5.6.2 Post-ruminal effects of supplements with low CP on total and individualvolatile fatty acids
5.6.3 Effects of supplements on total and greenhouse gases production
5.6.4 Rumen p H, microbial protein synthesis, and NH3-N production ruminal andpost-ruminal
5.7 Discussion
5.8 Conclusion
CHAPTER 6: ADDITION OF DIFFERENT LEVELS OF RUMEN PROTECTED METHIONINE AS A CONCEIVABLE APPROACH TO DEPLOYING MAXIMUMTOTAL AND METHIONINE AMINO ACID FLOW AT THE SMALL INTESTINE
6.1 Abstract
6.2 Introduction
6.3 Hypothesis and objective
6.4 Material and Methods
6.4.1 Experimental methodology and treatments
6.4.2 Laboratory analyses of experimental feed and collected samples
6.4.3 The methodology of preparation of Rusitec and in vitro fluid samples foramino acids analyses
6.4.4 The methodology of preparation of Rusitec and in vitro residue samples foramino acids analyses
6.4.5 Sample filtration and constant volume preparation for the amino acidanalyzer
6.5 Statistical analyses
6.6 Results
6.6.1 Low protein with RPMet supplementation their effects on EAA, NEAA andMet flow from the rumen to ileum residue
6.6.2 Low protein with RPMet supplementation their effects on EAA, NEAA andMet flow from rumen to ileum fluid
6.7 Discussion
6.8 Conclusion
CHAPTER 7: Conclusion and Recommendations
7.1 Conclusion
7.2 Recommendations
PUBLICATIONS
ACKNOWLEDGEMENTS
REFERENCES
APPENDIXA
ABBREVIATIONS
BIOGRAPHICAL SKETCH
本文编号：2881447
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