Understanding the Dairy Cow

Acknowledgements xiii Preface to the Third Edition xiv About the Companion Website xvi Part I How the Cow Works 1 1 Introduction – The Dairy Cow of Today 3 Milk as Food 6 Nutrient Supply 7 Healthy Digestion 8 Taste and Appetite 9 Do no Harm 9 Biological Efficiency of Milk Production 10 Milk Production: Species and Breed Comparisons 11 Efficiency of Feed Conversion to Milk, Eggs and Meat: Competitive and Complementary Feeds 12 Behaviour and Welfare 14 2 Digestion and Metabolism 18 Structure of the Digestive Tract 18 Eating and Rumination 22 Grazing 22 Salivation 23 Rumen Movements 23 Rumination 25 Digestion 26 Fermentation of Carbohydrates in the Rumen 28 Utilization of Metabolizable Energy for Maintenance and Production 31 Digestion of Crude Protein 32 Microbial Protein Synthesis 35 Truly Absorbed Amino Nitrogen 37 Urea Recycling 38 Digestion of Lipids 38 Absorption and Secretion of Minerals 39 Calcium Exchange 41 Appetite and Food Intake 42 3 Reproduction and Lactation 45 Anatomy of the Female Reproductive Tract 45 Follicle Development and Ovulation 45 The Oestrus Cycle 49 Puberty 49 Fertilisation 50 Pregnancy 51 Placental Transfer and Foetal Nutrition 53 Parturition 53 Dystocia 55 Lactation 56 Anatomy of the Udder 56 Milk Yield 58 Extended Lactations 59 Hormonal Control of Lactation 60 Reproduction in the Male 61 4 Environment, Behaviour and Welfare 64 Environmental Needs 64 Behaviour 65 Physical Comfort 66 Thermal Comfort 68 Sensible Heat Loss 68 Evaporative Heat Loss 69 Metabolic Heat Production 71 Climate, Production and Welfare 73 Tropical Climates 73 Cold Climates 74 Security and Social Behaviour 74 Sexual and Maternal Behaviour 75 Behaviour as an Indicator of Welfare 76 Part II Feeding the Dairy Cow 77 5 Nutrition: Supply and Demand 79 Nutrient Requirements and Responses 81 Nutrient Allowances for the Lactating Cow 84 Mineral Requirements 88 Nutritive Value of Feeds 90 Ration Formulation 93 Prediction of Food Intake 93 Assessment of an Existing Ration 94 Feeding Plans for Dairy Cows 95 Inputs 95 Outputs 96 Allowances for Growing Heifers 97 6 Feeds and Feeding Strategies 99 Pasture 100 Grazing Strategies 102 Legumes 104 Grass Silage 104 Dry Matter 105 Metabolisable Energy 106 Protein 106 Silage Additives 107 Hay 107 Straw 108 Ensiled Whole-crop Cereals 108 Other Green Feeds 109 Root Crops 109 Cereals 109 By-products 111 Oilseed Cakes and Meals 111 Miscellaneous By-products 113 Sugar Beet Pulp 113 Maize Gluten 113 Brewers’ and Distillers’ Grains 114 Wheat Bran 114 Balancing Forages and Concentrates 114 Feeding Strategies 117 Feeding to Yield 117 Total Mixed Rations and Flat Rate Feeding 119 7 Feeding Problems and Metabolic Diseases 121 Feeding Problems 123 Rumen Acidosis 123 Abomasal Disorders 125 Bloat 126 Metabolic Disorders 127 Ketosis 127 Prevention and Treatment 129 Parturient Hypocalcaemia (‘Milk Fever’) 130 Prevention and Treatment 131 The Downer Cow 132 Hypomagnesaemic Tetany (Grass Staggers) 133 Prevention and Treatment 135 Other Mineral Deficiencies 136 Phosphorus 136 Copper and Molybdenum 137 Cobalt 138 Selenium 138 Vitamin Deficiencies 139 Vitamin A 139 Vitamin D 140 Vitamin E 140 Last Words on Minerals and Vitamins 141 Part III Housing Health and Management 143 8 Healthy and Humane Housing and Handling 145 Accommodation 145 The Cow House 146 Cubicle Design 150 The Cubicle Bed 153 Passageways 154 Calving and Isolation Boxes 154 Heifer Yards 156 Handling Facilities 156 Lameness 157 Conditions that Cause Lameness 159 Sole Haemorrhage and Sole Ulcers 159 White Line Disease 161 Digital Dermatitis 161 Interdigital Necrobacillosis ‘Foul’ 162 Aseptic Laminitis, ‘Founder’ 162 Risk Factors for Lameness 162 Transport and Slaughter 164 Loading and Unloading 164 The Journey 165 A Gentle Death 166 9 Milking and Mastitis 168 The Milking Machine 171 The Milking Parlour 174 Hygiene in the Milking Parlour 174 Mastitis 175 Indicators of Mastitis 176 Contagious Mastitis 177 Environmental Mastitis 178 Summer Mastitis 180 Dry Cow Therapy 181 10 Miscellaneous Maladies 182 Signs of Disease 183 Sudden Death 183 Drooling 185 Abdominal Symptoms 186 Nervous Symptoms 187 Fever 187 Inappetence and Anorexia 188 Notifiable Diseases 189 Bovine Tuberculosis 191 Foot and Mouth Disease 192 Other Infectious Diseases 193 Bovine Viral Diarrhoea (BVD) 193 Johne’s Disease 194 Salmonellosis 194 Leptospirosis 195 Parasitic Diseases 195 Part IV Breeding and Fertility 197 11 Breeding 199 Selection Criteria 202 Genomic Selection 206 Sexed Semen 206 Cow Selection 207 Beef Bulls 209 12 Fertility 211 Fertility Management 212 Behaviour at Oestrus 212 Aids to Oestrus Detection 213 Synchronisation of Oestrus 216 Time of Insemination 217 Pregnancy Diagnosis 217 Rebreeding 219 Infertility 219 Ovarian Dysfunction 220 Uterine Disorders 221 Retained Placenta 221 Endometritis 222 Early Foetal Death 222 Abortion 223 Nutrition and Infertility 223 Condition Score at Calving? 225 Condition Score at the Time for Rebreeding? 225 Milk Yields in Early and Mid-lactation? 225 How Well Does Nutrient Supply Match Requirements? 226 Transition Management 226 Part V Cows, People and the Environment 229 13 Cows, People and the Living Environment 231 Most of Those who can Consume Too Much Meat and Milk 232 Food We Could Eat is Fed to Animals While the Poor Grow Hungry 233 Intensive Livestock Production is Incompatible with Animal Welfare 233 Livestock’s Long Shadow is Destroying the Planet 235 Methane Production and Climate Change 237 Pollution from Dairy Units 238 Alternative Husbandry Systems 240 Organic Dairy Farming 240 Traditional and Village Systems 241 Fair Play for Cows, People and the Planet 242 Herd Health and Welfare 242 Herd Health Management 243 Animal Welfare: Quality Assurance and Quality Control 243 Further Reading 247 Index 252