Gracey's Meat Hygiene

Description

Gracey’s Meat Hygiene, Eleventh Edition is the definitive reference for veterinarians working in meat hygiene control. This new edition of a classic text reflects the recent significant changes in science, legislation and practical implementation of meat hygiene controls in the UK, Europe and worldwide since the 10th edition was published in 1999. An excellent practical guide for teaching food hygiene to veterinary students worldwide, in addition to laying the foundations of food animal anatomy, pathology and disease. New chapters address the increased concern of both the public and inspectors to issues of animal welfare and recognise the role of the profession, and interest from the consumer, in environmental protection.

Key features include:

• Fully updated new edition, in a refreshed design with colour photographs and illustrations throughout.
• Includes new content on meat hygiene inspection covering the components of an integrated food safety management system as well as animal health and welfare controls in the ‘farm to fork’ system.
• A practical approach to health and safety in meat processing is outlined by identifying the hazards and then describing how these can best be controlled.
• With contributions from veterinary and industry experts, this edition is both a valuable teaching aid and a practical reference for veterinarians and all food business operators and their staff.

Table of Contents

Contributors
Preface
Acknowledgements

1 The food animals 1

• Dietary factors 2
• World livestock production 3
• UK meat plants and throughputs 4
• Cattle 4
• Breeds 4
• Systems of beef production 6
• Growth promoters 7
• Definitions 7
• Sheep 7
• Definitions 9
• Pigs 10
• Pig breeds 10
• Pig breeds in the United Kingdom 11
• Pig production 11
• Pig meat production 13
• Glossary of terms 13
• Additional facts 13
• Goats 13
• Poultry 14
• Definitions 14
• Rabbits 15
• Deer 16
• Handling of deer 17
• References 17
• Further reading 17
• Form animal welfare council 17

2 Anatomy 19

• Descriptive terms 19
• Osteology and arthrology 19
• Bones 19
• Digestive system 21
• Tongue 21
• Stomach 22
• Mucous membranes 22
• Intestines 23
• Liver 24
• Pancreas (gut sweetbread) 25
• Respiratory system 26
• Lungs 26
• Pluck 26
• Circulatory system (heart, arteries, capillaries and veins) 26
• Heart 26
• Portal circulation 27
• Spleen (melt) 27
• Lymphatic system 28
• Haemal lymph nodes 28
• Lymph nodes of the ox 29
• Nodes of the head and neck 30
• Nodes of the chest and forequarter 30
• Nodes of the abdomen and hindquarter 31
• Lymph nodes of the pig 33
• Head and neck 33
• Other nodes 33
• Urogenital system 34
• Urinary organs 34
• Genital organs 34
• Kidney 34
• Reproductive system 34
• Uterus 34
• Udder 36
• Endocrine system 36
• Thymus 36
• Adrenal (suprarenal) bodies 36
• Testicles (testes) 37
• Collection and yield of glands 37
• Skin 37
• Horns 37
• Muscular system 37
• Connective tissue 38
• Fat 38
• Determination of age by dentition 38
• Teeth 38
• Determination of sex 39
• Cattle 39
• Sheep 40
• Pigs 41
• Horse and ox differentiation 41
• Debasement of food
• (adulteration and substitution) 41
• Food tampering 43
• References 43
• Further reading 43

3 Meat establishment construction and equipment 45

• Site 45
• Environmental statement 45
• Submission of plans 46
• Area size 46
• Facilities 47
• Equipment design 50
• Pest control 51
• Small abattoir units 51
• Lairage 52
• Cattle lairage 52
• Sheep lairage 52
• Pig lairage 52
• Deer lairage 53
• Clipping or cleaning of livestock 53
• Manure disposal 53
• Slaughterhall 53
• Stunning area 53
• Bleeding area 54
• Cattle carcase dressing 54
• On-the-rail dressing 55
• Sheep slaughterhall 56
• Pig slaughterhall 57
• Singeing and scraping 58
• Refrigeration accommodation 58
• Detained meat room 59
• Condemned meat room 60
• Hide and skin store 60
• Gut and tripe room 60
• Red offal room 60
• The edible fat room 61
• Cutting rooms 61
• Equipment wash 61
• Fresh meat dispatch area 61
• Vehicle washing 62
• General amenities for personnel 62
• Veterinary office 62
• Treatment of effluent 62
• Pollution parameters 63
• Treatment 63
• Preliminary treatment: Screening, solids and grit removal 63
• Secondary treatment 64
• Further reading 65

4 Preservation of meat 67

• Physical changes in stored meat 67
• Chemical changes in stored meat 68
• Water activity or water availability (aw ) 68
• Meat curing 68
• Salt 68
• Ingredients used in curing 69
• Production of bacon and ham 69
• Cutting 70
• Application of the pickle 70
• Production of cooked hams 71
• Traditional dry-cured bacon 71
• Alternative dry cure 71
• Smoking 71
• Common defects in cured meat 71
• Micro-organisms on cured product 72
• Refrigeration 72
• Mechanical refrigeration 72
• Chilling of meat 73
• Freezing of meat 75
• Freeze-drying or lyophilisation 76
• Storage of fresh meat 76
• Vacuum packing 76
• Modified atmosphere packing 76
• Refrigerated meat transport and storage 76
• Changes in frozen meat 77
• ‘Weeping’ or ‘drip’ 77
• Durability of frozen meat 78
• Effect of freezing on pathogenic micro-organisms and parasites 78
• Heat: Thermal processing 78
• Traditional canning methodology 79
• Treatment of food to be canned 79
• Canning operations 80
• Canning of meats 82
• Foods packed in glass 82
• Spoilage in canned foods 82
• Types of spoilage 83
• The public health aspect of canned foods 85
• Other methods of meat preservation 86
• Antioxidants 86
• Preservatives 86
• Irradiation 86
• Infrared radiation 86
• Ultraviolet radiation 86
• Ionising radiation 86
• High pressure 87
• References 87
• Further reading 88

5 Plant sanitation 89

• Reasons for cleaning and disinfecting plant 89
• ‘Scotoma effect’ or ‘factory-blindness’ 90
• The chemistry of cleaning 90
• The soil 91
• The substrate: Materials of construction 91
• Energies of cleaning 92
• Chemical and physical reactions of cleaning 92
• Detergents: Design and choice 95
• Principles of disinfection 95
• Biocidal active components 95
• Disinfectants: Design and choice 97
• Hygiene equipment and application methods 97
• Manual cleaning 98
• Foam cleaning 98
• Foam and disinfectant application equipment 98
• Gels 99
• Spray 100
• Fogging 100
• Knife and cutting tool disinfection during processing 100
• Machine washing 102
• Cleaning-in-place (CIP) 102
• Rinse systems 104
• Contamination and re-contamination 105
• Air 105
• Water 106
• People 106
• Surfaces 106
• Cleaning procedures 106
• The cleaning sequence 106
• Monitoring of hygiene 108
• Training 110
• Safety 110
• Effluent and external odour control 110
• Conclusion 111
• Note 111
• References 112

6 From farm to slaughter 113

• Production of clean, healthy livestock 113
• Clean livestock 115
• Healthy livestock 117
• Safe use of animal medicines 117
• Safe disposal of animal waste 117
• Animal welfare on the farm 119
• Assessment of an animal’s welfare 119
• Transportation of livestock 122
• Loading and unloading 122
• The journey to slaughter 123
• EU transport legislation 123
• Protection during transport 123
• Means of transport 123
• Space allowances 123
• Duties of transporters 123
• Feed, water and rest periods 123
• Treatment of sick animals 124
• Travel documentation 124
• Loss of weight during transport 124
• Transport mortality 125
• Lairage construction 126
• Animal husbandry in the lairage 127
• Moving animals within the lairage 127
• Social stress 128
• Watering 128
• Fasting 128
• Resting of animals prior to slaughter 129
• Pre-slaughter handling and meat quality 129
• Stress and the animal 129
• Stress and meat quality 130
• Pre-slaughter feeding of sugars 131
• Traumatic injury 131
• Time of bruising 131
• Rough handling 132
• Presence of horns 132
• Temperament 132
• Stunning box design 132
• Mixing of animals 133
• Breed 133
• Incentives and education 133
• References 133
• Further reading 134

7 Humane slaughter 135

• Pre-slaughter handling/restraint 136
• Cattle movement and restraint 136
• Pig movement and restraint 137
• The slaughtering process 137
• Assessment of unconsciousness at slaughter 137
• Methods of stunning 138
• Percussive stunning 138
• Head sites for percussive stunning 140
• Water jet stunning 142
• Carbon dioxide and other gas mixtures 142
• Electrical stunning 144
• Effect of stunning on meat quality 146
• Slaughter of minor species 146
• Slaughter of deer 146
• Slaughter of ostriches 147
• Slaughter of rabbits 147
• Other methods of slaughter 147
• Slaughter of poultry 148
• Electrical stunning of poultry 148
• Assessment of unconsciousness in electrical water bath stunned poultry 149
• Stunning/killing poultry with controlled atmospheres 149
• Percussive stunning of poultry 150
• Other methods of slaughter 150
• Effects of stunning on poultry meat quality 150
• Pithing 150
• Bleeding 151
• Cattle 151
• Sheep 151
• Pigs 152
• Efficiency of bleeding 153
• Slaughter without pre-stunning 153
• Shechita – Jewish religious slaughter 153
• Muslim methods of slaughter 156
• Slaughter of poultry without stunning 157
• References 157
• Further reading 158

8 Meat hygiene practice 159

• Meat and animal by-products 159
• Hygienic production 159
• Sources of contamination 159
• Outer integument – hide, hair, fleece or skin 159
• Gastrointestinal tract 160
• Stunning and sticking 160
• Physical contact with structures 160
• Operatives 160
• Equipment and utensils 161
• The slaughter hall environment 161
• Vermin and pests 161
• Chemical contamination 162
• Methods of reducing contamination 162
• Dealing with the dirty animal 162
• Clipping cattle on line 163
• Protecting the meat from the worker 163
• Good hygiene practice 165
• Layout and flow lines 167
• Dressing techniques – Removal of hide/fleece/hair 167
• Preventing contamination from the gastrointestinal tract 170
• Post-slaughter decontamination 172
• Water 172
• Trimming 173
• Chemical treatments 173
• Bacteriophages 174
• Ultraviolet and pulsed high-intensity light 174
• Outputs of the slaughterhouse 174
• Treatment of edible co-products 175
• Fats 175
• Edible fat rendering 176
• Stomach and intestines 176
• Bones 177
• Hides and skins 177
• Animal by-products 178
• Category 1 178
• Category 2 179
• Category 3 (can be used for pet food) 180
• Materials for technical uses 181
• Hygiene requirements for animal by-product processing establishments 183
• Rendering processes 183
• References 184

9 Meat inspection protocols 185

• The case for change 185
• The holistic approach 187
• Integrated Food Safety Assurance 187
• Farm to fork 187
• Food chain information 187
• Ante-mortem inspection 188
• Ante-mortem inspection procedure in the slaughter establishment 189
• Practical ante-mortem procedure 190
• Emergency slaughter animals 191
• Emergency slaughter: The decision on farm 191
• Emergency slaughter: The decision at the slaughter establishment 192
• Post-mortem inspection 192
• Facilities for post-mortem inspection 192
• Carcase identification and traceability 193
• Traditional post-mortem inspection 194
• Traditional post-mortem inspection of cattle 194
• Traditional post-mortem inspection of calves 196
• Traditional post-mortem inspection of sheep and goats 196
• Traditional post-mortem inspection of pigs 196
• Traditional post-mortem inspection of equines 197
• Traditional post-mortem inspection of poultry 197
• Decisions at post-mortem examination 198
• Common post-mortem findings 203
• Abscesses 203
• Omphalophlebitis 204
• Arthritis 204
• Oedema 204
• Pneumonia and pleurisy 205
• Endocarditis 206
• Pericarditis 207
• Pyelonephritis 207
• Bruising 208
• Pigmentation 208
• Haematogenous pigments 209
• Bile pigments 209
• Porphyrin 210
• Lipofuscin (‘wear-and-tear pigment’, pigment of brown atrophy, lipochrome, haemofuscin) 211
• Xanthosis (xanthomatosis, osteohaematochromatosis, brown atrophy) 211
• Tumours 211
• Classes of tumours 212
• Causes of tumours 212
• Effect on host 212
• Nomenclature of neoplasms 212
• Judgement of neoplasia 213
• Poor condition/emaciation 213
• Contamination 215
• Parasitic conditions 215
• Ascaris suum 215
• Echinococcus granulosus: Hydatidosis and hydatid cyst 215
• Taenia hydatigena (known as Cysticercus tenuicollis in larval stage) 216
• Taenia ovis (previously known as Cysticercus ovis) 216
• Fasciola hepatica: Liver fluke 216
• Paramphistomiasis 216
• Sarcocystis 216
• Courses of action 217
• Utilisation of post-mortem data 218
• Control of hygienic production 218
• Hazard analysis and critical control points (HACCP) 219
• Implementation of an HACCP system 219
• Worldwide food safety standards 221
• References 222
• Further reading 222

10 Poultry production, slaughter and inspection 223

• Production of poultry 223
• Poultry feedingstuffs 225
• Poultry flock health 226
• Catching and crating 226
• Reception and unloading 227
• Pre-slaughter inspection 228
• Shackling 228
• Stunning and slaughter 229
• Scalding and defeathering 230
• Defeathering 231
• Evisceration 232
• Chilling 235
• Ante-mortem health inspection 237
• Post-mortem inspection in the plant 240
• Decision of the official veterinarian at the post-mortem inspection 241
• General contamination 242
• Guidelines on trimming poultry 242
• Coliform infections 243
• Salmonellosis 243
• Campylobacteriosis 244
• Chlamydiosis (psittacosis/ornithosis) 245
• Miscellaneous conditions 245
• Dead on arrival 245
• Bruising and fractures 245
• Breast blisters and hock burn 246
• Ascites 246
• Slaughter liver or cholangiohepatitis 246
• Fatty liver haemorrhagic syndrome (FLHS) 246
• Vices 246
• Contamination 247
• Decomposition 247
• Barking 247
• Diseases of the female reproductive system 247
• Oregon disease 247
• Over-scald 247
• Fevered carcases 247
• Septicaemia 247
• Insufficient bleeding 247
• Emaciation 247
• Viscera absent 247
• References 248
• Further reading 248

11 Exotic meat production 249

• Rabbits 249
• Slaughter 249
• Inspection 250
• Post-mortem judgements in rabbit meat inspection 250
• Zoonoses 251
• Guidelines on contamination, missing viscera and trimming 252
• Farmed deer 252
• Handling and slaughter 252
• Park deer 254
• Wild deer 254
• Killing 254
• Ostriches 255
• Restraint 256
• Stunning 256
• Dressing 256
• Changes after slaughter 257
• Commercial squab production 257
• Further reading 257

12 Food poisoning and meat microbiology 259

• Part 1: Food poisoning 259
  • Types of food poisoning 259
  • Surveillance of food poisoning 259
  • Laboratory reports of enteric infections 260
  • Outbreak surveillance 261
  • General considerations 261
  • Food-borne pathogens 261
• Part 2: Meat microbiology 267
  • Bacteriological examination of carcases 267
• Part 3: Meat decomposition and spoilage 271
  • Assessment of decomposition 277
  • Further reading 278

13 Controls on veterinary drug residues in the European Union 279

• Legal framework 279
• Licensed veterinary medicines 279
• Hormones and ß-Agonists 280
• Prohibited compounds 280
• Unauthorised and unlicensed compounds 281
• Regulatory limits: MRLs, MRPLs and RPAs 281
• The National Residue Control Plan in EU member states 282
• Compound groups 282
• Sampling levels for each species 282
• Relationship between species and substance to be analysed 283
• Testing procedures and performance characteristics 284
• Testing procedures 284
• CCa and CCß 285
• Sampling of imported food 285
• Legal basis for sampling of imports from third countries 285
• Frequency of sampling of imports from third countries 285
• Interpretation of non-compliant results 285
• The Rapid Alert System for Food and Feed (RASFF) 285
• Legal basis and description of the RASFF 285
• RASFF notification types 286
• Notification basis 286
• Action taken 286
• Distribution status 286
• Actions taken following infringements 286
• Analytical methods: Technical aspects 287
• Method specificity 287
• Performance characteristics 288
• Method validation 288
• Proficiency testing 289
• References 289

14 Health and safety in meat processing 291

• Accident statistics 291
• UK legislation 291
• General duties 292
• Key topics requiring risk assessment 293
• Being struck by hand tools including knives 293
• Musculoskeletal disorders 294
• Slips, trips and falls 298
• Contact with machinery 298
• Transport 301
• Falls from a height 301
• Substances/microorganisms 302
• Zoonoses 303
• Specific control measures for zoonoses 303
• Animals 310
• Noise 310
• Cold environment 311
• General requirements 312

References 316
Index 319

Authors

David S Collins, MVB, DVPH(MH), MRCVS
Formally City Veterinarian for Belfast, he has served as a Member of Northern Ireland Food Standards Advisory Committee as well as on the Meat Hygiene Advisory Committee of the UK Food Standards Agency.His work has involved forensic investigation for the Ministry of Defence and insurance companies, advising veterinary pharmaceutical companies regarding adverse reactions, product registration and clinical trials, and advising the government on animal experimentation including clinical trials for veterinary pharmaceuticals. He is a former Chief Examiner for the Royal College of Veterinary Surgeons in Veterinary Public Health, and was Consultant Editor for Northern Ireland Veterinary Today.

Robert J Huey, TD, MVB, DVPH(MH), MRCVS
Robert is Chief Veterinary Officer in the Department of Agriculture and Rural Development Northern Ireland (DARDNI) veterinary service. He is currently Vice-President of the Federation of Veterinarians of Europe, and a past President of the Union of European Veterinary Hygienists. He is also a former President of the Veterinary Public Health Association, and was Senior Examiner in Veterinary Public Health for the Royal College of Veterinary Surgeons, 1998-2010.