圍產(chǎn)期是泌乳周期的關(guān)鍵時(shí)期,其特征在于生理,代謝和免疫學(xué)的變化。在圍產(chǎn)期間,奶牛的營(yíng)養(yǎng)需求顯著增加,并且由于采食量的降低使得奶牛不能滿足其營(yíng)養(yǎng)需求,導(dǎo)致能量負(fù)平衡的發(fā)生以及脂肪組織的動(dòng)員。調(diào)整產(chǎn)犢前的能量飼喂水平及添加過瘤胃賴氨酸是減輕能量負(fù)平衡的有害影響,并可能改善奶牛整體生產(chǎn)性能的關(guān)鍵性因素。然而,圍產(chǎn)期能量飼喂水平和添加過瘤胃賴氨酸對(duì)奶牛的綜合影響尚未得到很好的探究。本研究的目的是探究產(chǎn)犢前能量飼喂水平和添加過瘤胃賴氨酸對(duì)圍產(chǎn)期奶牛的生產(chǎn)性能、血液生化指標(biāo)、肝臟功能及其抗氧化狀態(tài)的影響。68頭第三胎且即將進(jìn)入第4次泌乳期的奶牛被隨機(jī)分配到4個(gè)處理中,采用2 x 2因子設(shè)計(jì),分別飼喂兩種不同能量水平[高產(chǎn)奶凈能(NE_L)=1.53Mcal/kg DM(HE)和低NE_L=1.37Mcal/kg DM(LE)]的日糧以及添加過瘤胃賴氨酸40 g/cows(過瘤胃賴氨酸,Blys)和賴氨酸(對(duì)照,CK)。所以,4個(gè)處理分別為低能量日糧+過瘤胃賴氨酸(LEBlys)、低能量日糧+賴氨酸(LECK)、高能量日糧+過瘤胃賴氨酸(HEBlys)和高能量...

【文章頁(yè)數(shù)】：189 頁(yè)

【學(xué)位級(jí)別】：博士

【文章目錄】：
摘要
ABSTRACT
LIST OF ABBREVIATIONS
CHAPTER 1.INTRODUCTION
    1.1.JUSTIFICATION OF THE STUDY
    1.2.GENERAL HYPOTHESIS
    1.3.GENERAL OBJECTIVES
CHAPTER 2.LITERATURE REVIEW
    2.1.Dry matter intake during the transition period
        2.1.1.Transition period
        2.1.2.Dry matter intake
        2.1.3.Regulation of dry matter intake
    2.2.Dietary energy and energy metabolism
        2.2.1.Dietary energy requirement of dairy cows
        2.2.2.Feeding of dietary energy density to dairy cows during the far-off period
        2.2.3.Feeding of dietary energy density to dairy cows during the close-up period
        2.2.4.Negative energy balance
        2.2.5.Gluconeogenesis
    2.3.Energy metabolites
        2.3.1.Concentrations of free fatty acids
        2.3.2.Fatty Liver
        2.3.3.Ketogenesis
    2.4.Biomarkers of blood metabolites of liver functions
    2.5.Dietary lipids and fat metabolism
        2.5.1.Digestion of dietary lipids
        2.5.2.Carnitine biosynthesis
        2.5.3.Functions of carnitine
    2.6.Oxidative stress and antioxidant status
    2.7.Dietary protein and protein metabolism
        2.7.1.Essential and non-essential amino acids
        2.7.2.Dietary protein requirement
        2.7.3.Protein metabolism
        2.7.4.Limiting Amino acids
        2.7.5.Rumen-Protected Lysine
    2.8.Implications of milk urea and blood urea nitrogen
    2.9.Interrelationship of body condition score and milk production
    2.10.Causes of periparturient immunosuppression
        2.10.1.Energy metabolites and immunosuppression
        2.10.2.Factors contribute to immune-suppression during the transition period
CHAPTER 3.EFFECTS OF CLOSE-UP DIETARY ENERGY LEVEL AND SUPPLEMENTING RUMEN-PROTECTED LYSINE ON ENERGY METABOLITES AND MILK PRODUCTION IN TRANSITION COWS
    3.1.INTRODUCTION
    3.2.MATERIALS AND METHODS
        3.2.1.Experimental design and experimental cows
        3.2.3.Dietary treatment rations and cows housing
        3.2.4.Sampling,measurements,and analysis
        3.2.5.Statistical analysis
    3.3.RESULTS AND DISCUSSION
        3.3.1.Pre and postpartum dry matter intake
        3.3.2.Effects on free fatty acid concentrations
        3.3.3.Effects onβ-hydroxybutyrate concentrations
        3.3.4.Effects on milk yield and composition
    3.4.CONCLUSIONS
CHAPTER 4.EVALUATION OF BIOMARKERS OF BLOOD METABOLITES AND LIVER FUNCTIONS IN DAIRY COWS FED PRE-PARTUM ENERGY DENSITY AND RUMEN-PROTECTED LYSINE DURING THE TRANSITION PERIOD
    4.1.INTRODUCTION
    4.2.MATERIALS AND METHODS
        4.2.1.Experimental design and experimental cows
        4.2.2.Blood samples collection and plasma metabolites analyses
        4.2.3.Statistical analysis
    4.3.RESULTS
        4.3.1.Effects on glucose and insulin concentrations
        4.3.2.Effects on plasma albumin and blood urea nitrogen concentrations
        4.3.3.Effects on plasma IGF-1and total bilirubin concentrations
        4.3.4.Effects on ALT,AST,TC and TG concentrations
    4.4.DISCUSSION
    4.5.CONCLUSIONS
CHAPTER 5.EVALUATION OF MALONDIALDEHYDE CONCENTRATIONS AND ANTIOXIDANT STATUS IN DAIRY COWS FED CLOSE-UP ENERGY DENSITY AND RUMEN-PROTECTED LYSINE DURING THE TRANSITION PERIOD
    5.1.INTRODUCTION
    5.2.MATERIALS AND METHODS
        5.2.1.Experimental design and dietary treatment rations
        5.2.2.Blood samples collections and analysis of antioxidant status in blood serum
        5.2.3.Analysis of antioxidant status and malondialdehyde in blood serum
        5.2.4.Statistical analysis
    5.3.RESULTS
        5.3.1.Effects on blood serum superoxide dismutase activity
        5.3.2.Effects on serum glutathione peroxidase activity
        5.3.3.Effects on serum total antioxidant capacity
        5.3.4.Effects on serum malondialdehyde concentrations
    5.4.DISCUSSIONS
    5.5.CONCLUSIONS
CHAPTER 6.RELATIONSHIP OF CLOSE-UP COWS BODY WEIGHT,BODY CONDITION SCORE WITH COWS PRODUCTION PERFORMANCE,ANDΒ-HYDROXYBUTYRATE LEVELS DURING EARLY LACTATION
    6.1.INTRODUCTION
    6.2.MATERIALS AND METHOD
        6.2.1.Experimental design and selection of experimental cows
        6.2.2.Blood samples collection
        6.2.3.Milk samples collection
        6.2.4.Statistical analysis
    6.3.RESULTS AND DISCUSSION
        6.3.1.Correlation of close-up BCS with milk yield and composition during early lactation
        6.3.2.Correlation of BCS with,BHBA,milk yield,and compositions in early lactation
        6.3.3.Correction of BHBA with milk yield and composition during early lactation
        6.3.4.Relationship of close-up cows body weight with BCS,milk yield and compositions
    6.4.CONCLUSIONS
CHAPTER 7.GENERAL CONCLUSIONS
REFERENCES
APPENDIX
ACKNOWLEDGEMENTS
AUTHOR'S RESUME



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