1.1 ANIMAL PRODUCTION OR RESOURCE UTILISATION.
1.2 TECHNOLOGY TRANSFER
1.3 FOOD ENERGY
1.4 LIVESTOCK MANAGEMENT AND SOCIO-ECONOMIC ASPECTS.
1.5 EDUCATION & RESEARCH: DEVELOPMENTAL TOOLS
1.6 A LIVESTOCK DEVELOPMENT STRATEGY ...
1.7 CHOICE OF SPECIES & PRODUCTION SYSTEM
1.8 COMMUNICATION
1.9 CONCLUSIONS
2: LIVESTOCK DEVELOPMENT STRATEGIES
2.1 MAJOR ISSUES
2.2 DRAUGHT ANIMALS
2.3 DUAL PURPOSE MILK & BEEF PRODUCTION
2.4 RESTRICTED SUCKLING
2.5 GENOTYPE-ENVIRONMENT INTERACTIONS
2.5.1 Effects on production traits.
2.5.2 Heat tolerance
2.5.3 Parasitism
2.6 INTEGRATION: LIVESTOCK WITH CROPS
2.6.1 Livestock and food crops
2.6.2 Livestock and tree crops
2.6.3 Livestock and waste disposal
3: DIGESTIVE PHYSIOLOGY OF RUMINANTS
3.1 INTRODUCTION
3.2 THE DIGESTIVE TRACT OF HERBIVORES
3.2.1 Ruminant digestive tract
3.2.2 The rumen environment
3.2.3 Rumination
3.2.4 Rumen microbial ecosystem
3.3 RUMEN ORGANISMS
3.3.1 The phycomycetous fungi
3.3.3 Bacteria
3.3.4 Other organisms in the rumen
3.4 MICROBIAL INTERACTIONS IN THE RUMEN
3.4.1 Bacteria-bacteria interactions
3.4.2 Protozoa-bacteria interactions
3.4.3 Interactions of bacteria, fungi and protozoa
3.4.4 Conclusions
3.5 ENERGY TRANSACTIONS IN THE RUMEN.
3.5.1 Fermentation of carbohydrate .
3.5.2 Fate of dietary fat in the rumen.
3.5.3 Microbial growth and fermentation
3.5.4 Factors affecting the quantities of rumen microbes available for digestion in the small intestines
3.5.5 Maintenance-ATP (MATP) requirements of rumen micro-organisms
3.6 MODEL OF FERMENTATION IN THE RUMEN
Fermentation of carbohydrate . . . .
Fate of dietary fat in the rumen . . .
Microbial growth and fermentation.
Factors affecting the quantities of rumen microbes available for digestion in the small intestines . . . . . . . . . . . . . . . . . . . . . . . . . ..
3.5.5 Maintenance-ATP (MATP) requirements of rumen micro-organisms
MODEL OF FERMENTATION IN THE RUMEN
3.6.1 Stoichiometry ...................................................................... .
3.6.2 Energy losses in ferulentation ..................................... .
3.6.3 The balance of microbial protein to VFA energy (P IE ratio)
3.6.4 Protein fermentation and P IE ratio
3.6.5 Significance of PIE ratio .....
N-TRANSACTIONS IN THE RUMEN ..
3.7.1 Dietary nitrogen ................................................ .
3.7.2 Degradation of dietary protein in the rumen.
3.7.3 Outflow of dietary and endogenous nitrogenous materials from the rumen.
3.7.4 Peptides and amino acids in rumen fluid ...................... .
3.7 .. 5 Rumen amnlonia pool. ". ................................................. .
3.7.6 Recycling of N to the rumen from plasma urea
3.7.7 Urea (ammonia) toxicity
3.7.8 Other sources of non-protein nitrogen (NPN)
SULPHUR NUTRITION OF RUMINANTS.
3.8.1 Sulphur utilisation in the rumen
3.8.2 Toxicity of sulphur
FERMENTATION IN THE LOWER GUT.
ABSORPTION
4.1 VFA METABOLISM. . . . . . . . . . .
4.2 GLUCOSE METABOLISM. . . . . . .
4.2.1 Glucose as an essential nutrient
4.2.2 The contribution of propionate to glucose synthesis
4.2.3 Amino acid metabolism and glucose synthesis . . . .
4.2.4 Long-chain fatty acid synthesis and glucose metabolism.
4.2.7 Acetogenic/glucogenic ratios in rUUlen end-products: requirements for body fat synthesis. . . . .
4.2.8 Conclusion
4.3 THE BALANCE OF NUTRIENTS ABSORBED 57
4.4 NUTRIENTS FOR WORK. . . . . . . . . . . . . . 57
4.4.1 Availability of su bstrates for muscle metabolism 58
4.4.2 The effects of work on overall metabolic activity 58
4.4.3 Physiology of muscle contraction . . . . . . 58
4.4.4 Types of striated muscle. . . . . . . . . . . . 59
4.4.5 High-energy phosphate balance in muscles 60
4.4.6 Sources of energy for muscle . . . . . . . . . 60
4.4.7 Pathways of metabolism of substrates by skeletal muscle 60
4.4.8 Substrate use and heat production . . . . . . . . . . . . . 62
4.4.9 Substrates used by resting muscle. . . . . . 62
4.4.10 The effect of exercise on substrate use in the hind limb 63
4.4.11 Preferred substrates of skeletal muscle. .. ................................................................................................................ 64
4.5 NUTRIENTS FOR WORK OR PRODUCTION
4.5.1 Work ............................................. .
4.5.2 Work vs milk production
4.5.3 Work vs pregnancy ................ .
4.5.4 Conclusion ................................. .
4.6 NUTRIENT REQUIREMENTS FOR PRODUCTION
4.6.1 Tissue growth ................................................. .
4.6.2 Growth of the foetus and placenta ........................... .
4.6.3 Milk production ................................................................. .
4.7 GLUCOSE AVAILABILITY & PRODUCTIVITY
4.7.1 Evidence from feeding trials ....................................... .
4.7.2 Evidence from infusion of metabolites .................. .
4.7.3 Evidence from studies with lactating animals
4.8 OTHER CONSIDERATIONS ....................................................... .
4.8.1 Stress and glucose availability ........................................ .
4.8.2 Glucose availability from forage/sugar versus grain based diets
4.8.3 Balance of nutrients in starving animals ............................................ .
4.8.4 Physiological state: balance of nutrients and feed intake
4.8.5 Genotype: balance of nutrients
4.9 CONCLUSIONS .
5: MANIPULATION OF FEEDING & THE RUMEN ECOSYSTEM
5.1 CHEMICAL TREATMENTS OF ROUGHAGE
5.1.1 Ammoniation .....
5.1.2 Acid gas treatments
5.1.3 Steam treatment ...
5.2 INCREASING FIBRE DIGESTIBILITY IN THE RUMEN
5.2.1 Rumen ammonia <,/ ................................................................................ .
5.2.2 Availability of peptides and amino acids
5.2.3 Other nutrients ............................................................. .
5.2.4 Maintenance of a large 'free-floating' pool of cellulolytic organisms
5.2.5 Protozoa and digestibility of fibrous feeds .. -fI/. •....•
5.3 ENHANCING RUMEN PROPIONIC ACID PRODUCTION ....................... .
5.4 ALTERING THE P /E RATIO ..................................................................................... .
5.4.1 Chemicals inhibiting proteolysis or amino acid deamination
5.4.2 Dilution rate ...................................... .
5.4.3 Protozoa - defaunation ................. .
5.5 MANIPULATING DIETARY FAT
6: CONTROL OF FEED INTAKE IN RUMINANTS
6.1 SOME PRACTICAL OBSERVATIONS 6.1.1 Animal behaviour
6.1.2 Selection ....................................................... .
6.1.3 Dysphagia .................................................... .
6.2 FACTORS IN FEED THAT AFFECT INTAKE
6.3 ANIMAL FACTORS & FEED INTAKE ........................... .
6.3.1 Physiological state ......................................................... .
6.3.2 Major factors involved in decreasing feed intake
6.3.3 Palatability and unpalat.ability .................................... .
6.3.4 Effects of exercise on feed intake ............................ .
6.3.5 Animal genotype and voluntary feed intake 6.3.6 Rumen distension and nutrient imbalance
6.3.7 Fatigue ................................................................................. .
6.3.8 Acetate clearance and feed intake control.
7: GUIDELINES FOR FEEDING SYSTEMS 103
7.1 INTRODUCTION .................................................................................................................................................. 103
7.1.1 Limitations to "conventional" feeding standards 103
7.1.2 An alternative approach. . . . . . . . . . . . . . . . 103
7.1.3 Anilnal response to non-conventional feed resources 104
7.1.4 Nutritive value. . . . . . . . . . . . . . . . . . . 105
7.2 NUTRIENT SUPPLY Vs PRODUCTIVE STATE 106
7.2.1 Introduction 106
7.2.2 Work..... 107
7.2.3 Maintenance 108
7.2.4 Growth.... 108
7.2.5 Reproduction. 108
7.2.6 Milk production 110
7.2.7 Wool or hair production. 111
7.2.8 Carry-over effects of imbalanced nutrition in early life 111
7.3 PRINCIPLES OF SUPPLEMENTATION . . . . . . . . . . . . 113
7.3.1 Balancing the rumen and the animal for critical nutrients 113
7.3.2 The role of minerals ................................................................................................................................ 115
7.4 CATEGORISATION OF FEED RESOURCES 116
7.4.1 Fermentable carbohydrate .................................................................................................................... 117
7.4.2 Fermentable nitrogen. . . . . . . . . . . . . 117
7.4.3 Supplements which contribute to creating an efficient rumen ecosystem 117
7.4.4 Bypass protein . . . . . . . . . . . . . . . . . 117
7.4.5 Bypass starch and glucogenic precursors .. . . . . . . . . . . . 118
7.4.6 Long-chain fatty acids . . . . . . . . . . . . . . . . . . . . . . . . . 118
7.4.7 Feeds and other materials with a capacity to manipulate the
rumen microbial biomass . . . . . . . . 118
7.5 NON-CONVENTIONAL SUPPLEMENTS. . . . . . 119
7.5.1 Livestock excreta . . . . . . . . . . . . . . . . . . 119
7.5.2 Legume forages and foliages from food crops. 119
7.5.3 Attributes of legumes as supplements 120
7.6 METHODS FOR EVALUATING FEEDS. . ]22
7.6.1 Sources of ferlnentable carbohydrates 123
7.6.2 Fermentable nitrogen. . . . . . . . . . . 123
7.6.3 Rumen function and feed resources. .............................................................................................. 124
7.6.4 Bypass protein. . . . . . /. 124
7.6.5 Glucogenic precursors 125
7.6.6 Long-chain fatty acids 125
7.6.7 Minerals......... 125
7.7 A STRATEGY FOR DEVELOPING FEEDING SYSTEMS
8: FEEDING SYSTEMS: STRAWS & AGRO-INDUSTRIAL BYPRODUCTS
8.1 FIBROUS CROP RESIDUES ....
8.1.] Factors influenc.ing nutritive value
8.1.2 Draught animals .................................. .
8.1.3 Growing animals ................................ .
8.1.4 Long-chain fatty acids (LCFA)
8.1.5 Milk production .................................. .
8.1.6 Wool growth ........................................ .
8.1.7 Metabolic disorders associated with ammoniation of feeds
8.2 FIBROUS AGRO·INDUSTRIAL BYPRODUCTS
8.3 FRESHLY HARVESTED GRASSES.
8.3.1 Legume forages ...................................... .
8.3.2 Bypass nutrients.
8.4 SUGARCANE ....................... .
8.4.1 Introduction .............. .
8.4.2 Whole sugarcane
8.4.3 Sugarcane tops.
8.4.4 Sugarcane pith ..
8.4.5 Final molasses ..
8.4.6 Metabolic disorders on molasses-feeding systems
8.4.7 Sugarcane juice ............................ .
8.4.8 Residual pressed cane stalk
8.5 SISAL BAGASSE & PULP.
8.5.1 Introduction ........................ .
8.6 BANANAS & PLANTAINS
8.6.1 Banana fruit .
8.6.2 Banana foliage .....
9: PASTURE-BASED FEEDING SYSTEMS
9.1 PASTURE AS A FEED RESOURCE .
9.1.1 Extensive ranching .......................................... .
9.1.2 Improving pastures with legumes ..
9.1.3 Management of legumes in pastures 9.1.4 Use of fertilisers to improve grassland 9.1.5 Pasture improvement and stocking rate
9.2 NUTRITIVE VALUE .......................................................... .
9.2.1 Supplementation of ruminants on green pastures
9.3 FEED INTAKE AT PASTURE ............................. .
9.4 SUPPLEMENTATION ............................................. .
9.4.1 General supplementation practices
9.4.2 Mineral supplements ................................... .
9.4.3 Fermentable nitrogen supplements
9.4.4 Bypass nutrient supplements .................. .
9.4.5 Other supplements ....................................... .
9.4.6 Dietary history, physiological state and supplementary feeding on dry pastures . . . . . . . . . . . . . . .
9.5 TRADITIONAL SYSTEMS BASED ON PASTURE
9.5.1 Communal grazing .............. .
9.5.2 Cut-and-carry grass ............. .
9.5.3 Transhumance systems.
9.6 DROUGHT FEEDING
9.6.1 Introduction ............................ .
9.6.2 Water econonlY .................... .
9.6.3 Nutritional aspects of sub-maintenance feeding 9.6.4 Strategies for feeding in drought
9.6.5 Responsibility for drought feeding
9.6.6 Conclusions on drought feeding ..
l0: PARASITE/NUTRITION INTERACTIONS
10.1 PARASITES AS A CAUSE OF PRODUCTION LOSSES 10.2 LIFE CYCLES OF PARASITES
10.2.1 Nematodes .............................................................. .
10.2.2 Strategic use of drenches .................................. .
10.3 NUTRITION-PARASITE INTERACTIONS. 10.3.1 Effects of parasites on rumen function.
10.3.2 Protein digestion in the small intestine/abomasum.
10.3.3 Parasites of the large intestine .................................................... .
10.3.4 Effects of site of parasitism on protein nutrition 186
10.4 METABOLISM IN THE ANIMAL 186
10.4.1 Effects of eetoparasites . 187
10.4.2 Conclusions . . . . . . . . . . .
189
l1:NUTRITIONAL PRINCIPLES: SMALLHOLDER LIVESTOCK SYSTEMS 191
11.1 INTRODUCTION ............................................................................................................................................... 191
11.2 SUPPLEMENTATION STRATEGIES. . . . . . 192
11.2.1 Supplementing low-nitrogen fibrous diets 192
11.2.2 Use of molasses/urea blocks 193
11.3 RESTRICTED SUCKLING ............................................................................................................................. 196
11.3.1 Conclusions. . . . . . . . . . . . . . . . . . . 198
11.3.2 Theoretical aspects of restricted suckling
199
12:PERSPECTIVES 201
12.1 INTRODUCTION ............................................................................................................................................... 201
12.2 RESEARCH: FUTURE NEEDS. 201
12.2.1 Digestive physiology 202
12.2.2 Metabolism. . . . . . . . . . 203
12.2.3 Feeding systems . . . . . . . 203
12.2.4 Evaluation of supplements 204
12.2.5 Fractionation of crops and crop residues 204
12.3 GUIDELINES FOR DEVELOPING FEEDING SYSTEMS 206
12.3.1 The inadequacies of the Metabolisable Energy system 206
12.3.2 The alternative approach of balanced nutrients 207
12.3.3 Computer models . . . . . . . . . 208
12.3.4 Conclusions. . . . . . . . . . . . . . . . . 208
12.4 DISEASE/PARASITE NUTRITION. . . . . 209
12.5 LIVESTOCK & RURAL DEVELOPMENT 209
12.5.1 Packaged supplements . . . . . . . . . . 209
12.6 MARKETING INFRASTRUCTURE. . . . 210
12.7 SOIL CONSERVATION & SOIL FERTILITY 211
12.7.1 Supplementation and overgrazing 211
12.7.2 Soil conservation and legumes 211
12.8 EDUCATION & EXTENSION 211
12.8.1 Training . . . . . . . . . 211
12.8.2 Communication . . . . 212
12.9 CONCLUDING REMARKS
14:INDEX