Intro
Contents
Yeast as a Source of Exogenous Enzymes in Ruminant Feeding
1 Introduction
2 Composition of Yeast Culture
3 Yeasts as a Source of Exogenous Enzymes
4 Production of Enzymes from Yeast
5 Yeast Enzymes and Feed Utilization
5.1 Dietary Fibre Utilization
5.2 Ruminal Fermentation Characteristics
5.3 Microbial Protein Synthesis
5.4 Milk Production, Composition and Quality
5.5 Growth Performance
5.6 Meat Quality
6 Source of Dietary Lipid/Microbial Lipid
7 Means of Counteracting the Negative Effects of Mycotoxins
8 Conclusions
References

Yeast Culture and Direct-Fed Microbes: Modes of Action and Beneficial Applications in Ruminants
1 Introduction
2 Mechanism of Action of Yeast Culture and Direct-Fed Microbes
2.1 Mechanism of Action of Yeast Culture
2.2 Mechanism of Action of Direct-Fed Microbes
3 Beneficial Applications of Yeast Culture and Direct-Fed Microbes
3.1 Effects of Yeast Culture and Direct-Fed Microbes on Animal Performance
3.1.1 Effect on Growth
3.1.2 Effect on Intake and Lactation Yield
3.2 Effects on Rumen Fermentation
3.2.1 Effects of YC
3.2.2 Effects of DFM

3.3 Effects on Rumen Microbiota
3.3.1 Effects of YC
3.3.2 Effects of DFMs
3.4 Beneficial Effects of Yeast Culture and Direct-Fed Microbes on Host Immunomodulation
3.4.1 Effects of YC
3.4.2 Effects of DFMs
4 Conclusion and Prospects
References
Effects of Exogenous Enzymes on the Nutritive Value of Some Fibrous Forage in Ruminant
1 Introduction
2 Definition of Exogenous Enzymes
3 Sources of Exogenous Enzymes
4 Roles of Exogenous Enzymes in Improving Nutritive Value of Animal Feeds
5 Impact of Exogenous Enzymes
5.1 Fermentation of Fibrous Feeds

5.2 Nutrient Digestibility
5.3 Ruminal Degradability and Gas Production
5.4 Nitrogen Balance and Microbial Protein Synthesis
5.5 Milk Production, Composition and Quality
5.6 Growth Performance and Meat Quality
6 Conclusions
References
Exogenous Fibrolytic Enzymes: For the Better Utilization of Guinea Grass and Rice Straw as Ruminant Feeds
1 Introduction
2 Material and Methods
2.1 Location and Ethical Approval of Experiments
2.2 Animals, Management and Enzyme Treatment
2.2.1 Experiment 1
2.2.2 Experiment 2

2.3 Experimental Procedure, Measurements and Sampling
2.4 Laboratory Analyses
2.5 Calculations and Statistical Analysis
3 Results
3.1 Experiment 1
3.2 Experiment 2
4 Discussion
4.1 Experiment 1
4.2 Experiment 2
5 Conclusions
References
Role of Exogenous Enzymes in Feed Digestibility and Reducing the Emission Intensity of Enteric Methane Production in Ruminants
1 Introduction
2 Poor-quality Roughage and its Degradation by Ruminants
3 Treatment of Poor-Quality Roughages
3.1 Exogenous Fibrolytic Enzymes