A comprehensive book MANAGEMENT, NUTRITION AND BIOSECURITY ......................... 2 1.0 INTRODUCTION ............................................................................... 3 2.0 ECONOMIC CONSIDERATIONS IN THE PREVENTION AND CONTROL OF POULTRY DISEASES .............................................. 6 2.1 General Principles ................................................................... 6 2.2 Fixed and Variable Costs in Poultry Production ..................... 7 2.3 Gross Marginal Analysis ......................................................... 8 3.0 HEALTH AND PERFORMANCE OF POULTRY IN TROPICAL CLIMATES.......................................................................................... 13 3.1 Physiological Effects of High Ambient Temperature ............. 13 3.2 Design of Housing in Tropical Countries ............................... 13 3.3 Management of Flocks at High Temperature.......................... 15 4.0 PREVENTION OF DISEASE ............................................................ 21 4.1 Mechanisms of Disease Transmission .................................... 21 4.1.1 Transovarial Route ..................................................... 21 4.1.2 Transmission on the Egg Shell ................................... 21 4.1.3 Direct Transmission ................................................... 21 4.1.4 Indirect Transmission ................................................. 22 4.1.5 Dissemination by Wind .............................................. 22 4.1.6 Biological Vectors ...................................................... 22 4.1.7 Feed ............................................................................ 22 4.1.8 Vaccines ..................................................................... 22 4.2 Biosecurity .............................................................................. 23 4.2.1 Conceptual Biosecurity .............................................. 23 4.2.2 Structural Biosecurity ................................................ 23 4.2.3 Operational Biosecurity ............................................. 24 4.3 Decontamination of Housing and Equipment ......................... 26 4.3.1 Definitions.................................................................. 26 4.3.2 Decontamination ........................................................ 26 i 4.3.3 Disinfectants............................................................... 26 4.3.4 Public Health Considerations ..................................... 27 4.4 Disinfection of Poultry Houses ............................................... 27 4.5 Control of Rodents .................................................................. 28 4.6 Control of Free-Living Birds .................................................. 29 4.7 Quality of Water ...................................................................... 30 5.0 VACCINATION AND MEDICATION ............................................... 35 5.1 General Principles ................................................................... 35 5.2 Significance of Maternal Antibody in Relation to Flock Protection ............................................... 35 5.3 Administration of Vaccines ..................................................... 38 5.4 Medication .............................................................................. 38 6.0 SPECIAL PROCEDURES RELATING TO CONTROL OF DISEASES IN POULTRY OPERATIONS ......................................... 46 6.1 Control of Disease in Multiplier Breeder Farms .................... 46 6.1.1 Structural Biosecurity ................................................ 46 6.1.2 Operational Biosecurity ............................................. 47 6.2 Control of Disease on Commercial Broiler Farms ................. 47 6.2.1 Structural Biosecurity ................................................ 47 6.2.2 Operational Biosecurity ............................................. 48 6.3 Control of Disease in Commercial Egg Production Units ...... 51 6.3.1 Operational Biosecurity ............................................. 51 6.4 Control of Disease in Hatcheries ............................................ 53 6.4.1 Structural Biosecurity ................................................ 53 6.4.2 Operational Biosecurity ............................................. 53 7.0 NUTRITION OF CHICKENS AND DIETARY DEFICIENCIES ..... 56 7.1 Establishing Nutritional Specifications .................................. 56 7.2 Nutrient Deficiencies .............................................................. 56 7.2.1 Causes of Nutrient Deficiencies ................................. 56 7.2.2 Low Energy Intake ..................................................... 57 7.2.3 Deficiencies of Proteins or Amino Acids ................... 57 7.2.4 Fats ............................................................................. 57 7.2.5 Oxidative Rancidity ................................................... 58 ii 7.2.6 Vitamin Deficiencies..................................................... 58 7.3 Quality Control in Feed Manufacture ..................................... 62 IMMUNOSUPPRESSIVE DISEASES ..................................................... 68 8.0 MAREK’S DISEASE .......................................................................... 69 8.1 Etiology................................................................................... 69 8.2 Occurrence and Economic Significance ................................. 69 8.3 Transmission ........................................................................... 69 8.4 Clinical Signs .......................................................................... 69 8.5 Pathology ................................................................................ 69 8.6 Diagnosis and Confirmation ................................................... 69 8.7 Prevention ............................................................................... 70 9.0 INFECTIOUS BURSAL DISEASE .................................................... 72 9.1 Etiology................................................................................... 72 9.2 Occurrence and Economic Significance ................................. 72 9.3 Transmission ........................................................................... 72 9.4 Clinical Signs .......................................................................... 72 9.5 Pathology ................................................................................ 73 9.6 Diagnosis ................................................................................ 73 9.7 Prevention ............................................................................... 73 10.0 CHICKEN ANEMIA........................................................................... 76 10.1 Etiology................................................................................... 76 10.2 Occurrence and Economic Significance ................................. 76 10.3 Transmission ........................................................................... 76 10.4 Clinical Signs .......................................................................... 76 10.5 Pathology ................................................................................ 76 10.6 Diagnosis ................................................................................ 76 10.7 Prevention ............................................................................... 76 RESPIRATORY DISEASES ..................................................................... 78 11.0 NEWCASTLE DISEASE ................................................................... 79 11.1 Etiology................................................................................... 79 11.2 Occurrence and Economic Significance ................................. 79 11.3 Transmission ........................................................................... 79 iii 11.4 Clinical signs........................................................................... 80 11.5 Pathology ................................................................................ 80 11.6 Diagnosis ................................................................................ 80 11.7 Prevention ............................................................................... 81 12.0 INFECTIOUS LARYNGOTRACHEITIS .......................................... 84 12.1 Etiology................................................................................... 84 12.2 Occurrence and Economic Significance ................................. 84 12.3 Transmission ........................................................................... 84 12.4 Clinical Signs .......................................................................... 84 12.5 Pathology ................................................................................ 84 12.6 Diagnosis ................................................................................ 84 12.7 Prevention ............................................................................... 85 13.0 AVIAN INFLUENZA ......................................................................... 87 13.1 Etiology................................................................................... 87 13.2 Occurrence and Economic Significance ................................. 87 13.3 Transmission ........................................................................... 87 13.4 Clinical Signs .......................................................................... 87 13.5 Pathology ................................................................................ 88 13.6 Diagnosis ................................................................................ 88 13.7 Control in Areas Where Exotic HPAI is Diagnosed ............... 88 13.8 Recent Outbreaks of H5N1 Avian Influenza .......................... 89 14.0 INFECTIOUS BRONCHITIS ............................................................. 93 14.1 Etiology................................................................................... 93 14.2 Occurrence and Economic Significance ................................. 93 14.3 Transmission ........................................................................... 93 14.4 Clinical Signs .......................................................................... 93 14.5 Pathology ................................................................................ 93 14.6 Diagnosis ................................................................................ 93 14.7 Prevention ............................................................................... 93 15.0 MYCOPLASMOSIS ........................................................................... 95 15. 1 Etiology................................................................................... 95 15.2 Occurrence and Economic Significance ................................. 95 15.3 Transmission ........................................................................... 95 15.4 Clinical Signs .......................................................................... 95 15.5 Pathology ................................................................................ 96 iv 15.6 Diagnosis ................................................................................ 96 15.7 Treatment ................................................................................ 96 15.8 Prevention ............................................................................... 96 16.0 CORYZA ............................................................................................. 99 16.1 Etiology................................................................................... 99 16.2 Occurrence .............................................................................. 99 16.3 Transmission ........................................................................... 99 16.4 Clinical Signs .......................................................................... 99 16.5 Pathology ................................................................................ 99 16.6 Diagnosis ................................................................................ 99 16.7 Treatment ................................................................................ 99 16.8 Prevention ............................................................................... 100 17.0 ASPERGILLOSIS ............................................................................... 101 17.1 Etiology................................................................................... 101 17.2 Occurrence and Economic Significance ................................. 101 17.3 Transmission ........................................................................... 101 17.4 Clinical Signs .......................................................................... 101 17.5 Pathology ................................................................................ 101 17.6 Diagnosis ................................................................................ 101 17.7 Prevention ............................................................................... 101 MULTIFACTORIAL CONDITIONS ....................................................... 104 18.0 SWOLLEN HEAD SYNDROME ...................................................... 105 18.1 Etiology................................................................................... 105 18.2 Occurrence and Economic Significance ................................. 105 18.3 Transmission ........................................................................... 105 18.4 Clinical Signs .......................................................................... 105 18.5 Pathology ................................................................................ 106 18.6 Diagnosis ................................................................................ 106 18.7 Treatment ................................................................................ 106 18.8 Prevention ............................................................................... 106 19.0 SEPTICEMIA AND AIRSACCULITIS.............................................. 108 19.1 Etiology................................................................................... 108 19.2 Occurrence and Economic Significance ................................. 108 19.3 Transmission ........................................................................... 108 v 19.4 Clinical Signs .......................................................................... 108 19.5 Pathology ................................................................................ 108 19.6 Diagnosis ................................................................................ 109 19.7 Treatment ................................................................................ 109 19.8 Prevention ............................................................................... 109 SYSTEMIC DISEASES ............................................................................. 111 20.0 SALMONELLOSIS-PULLORUM DISEASE ................................... 112 20.1 Etiology................................................................................... 112 20.2 Occurrence and Economic Significance ................................. 112 20.3 Transmission ........................................................................... 112 20.4 Clinical Appearance ................................................................ 112 20.5 Pathology ................................................................................ 112 20.6 Diagnosis ................................................................................ 112 20.7 Treatment ................................................................................ 113 20.8 Prevention ............................................................................... 113 21.0 SALMONELLOSIS-FOWL TYPHOID ............................................. 114 21.1 Etiology................................................................................... 114 21.2 Occurrence and Economic Significance ................................. 114 21.3 Transmission ........................................................................... 114 21.4 Clinical Signs .......................................................................... 114 21.5 Pathology ................................................................................ 114 21.6 Diagnosis ................................................................................ 114 21.7 Treatment ................................................................................ 114 21.8 Prevention ............................................................................... 115 22.0 SALMONELLOSIS-PARATYPHOID................................................ 116 22.1 Etiology................................................................................... 116 22.2 Occurrence .............................................................................. 116 22.3 Economic Significance ........................................................... 116 22.4 Transmission ........................................................................... 116 22.5 Clinical Signs .......................................................................... 116 22.6 Pathology ................................................................................ 116 22.7 Diagnosis ................................................................................ 117 22.8 Treatment ................................................................................ 117 22.9 Prevention ............................................................................... 117 vi 23.0 PASTEURELLOSIS ............................................................................ 120 23.1 Etiology................................................................................... 120 23.2 Occurrence and Economic Significance ................................. 120 23.3 Transmission ........................................................................... 120 23.4 Clinical Signs .......................................................................... 120 23.5 Pathology ................................................................................ 120 23.6 Diagnosis ................................................................................ 121 23.7 Treatment ................................................................................ 121 23.8 Prevention ............................................................................... 121 24.0 SPIROCHETOSIS ............................................................................... 124 24.1 Etiology................................................................................... 123 24.2 Occurrence and Economic Significance ................................. 123 24.3 Transmission ........................................................................... 123 24.4 Clinical Signs .......................................................................... 123 24.5 Pathology ................................................................................ 123 24.6 Diagnosis ................................................................................ 123 24.7 Treatment ................................................................................ 123 24.8 Prevention ............................................................................... 123 25.0 AVIAN ENCEPHALOMYELITIS ..................................................... 124 25.1 Etiology................................................................................... 124 25.2 Occurrence and Economic Significance ................................. 124 25.3 Transmission ........................................................................... 124 25.4 Clinical Signs .......................................................................... 124 25.5 Pathology ................................................................................ 124 25.6 Diagnosis ................................................................................ 124 25.7 Prevention ............................................................................... 124 26.0 ADENOVIRAL INFECTIONS ........................................................... 126 26.1 Etiology................................................................................... 126 26.2 Occurrence and Economic Significance ................................. 126 26.3 Transmission ........................................................................... 126 26.4 Adenoviral Respiratory Infection ........................................... 126 26.4.1 Clinical Signs ............................................................. 126 26.4.2 Pathology ................................................................... 126 26.4.3 Diagnosis.................................................................... 127 26.4.4 Prevention .................................................................. 127 26.5 Inclusion Body Hepatitis ........................................................ 128 vii 26.5.1 Clinical Signs ............................................................. 127 26.5.2 Lesions ....................................................................... 127 26.5.3 Diagnosis .................................................................... 127 26.5.4 Prevention .................................................................. 127 26.6 Egg Drop Syndrome ............................................................... 127 26.6.1 Clinical Signs ............................................................. 127 26.6.2 Lesions ....................................................................... 128 26.6.3 Diagnosis .................................................................... 128 26.6.4 Prevention .................................................................. 128 27.0 RUNTING SYNDROME .................................................................... 130 27.1 Etiology................................................................................... 130 27.2 Occurrence and Economic Significance ................................. 130 27.3 Transmission ........................................................................... 130 27.4 Clinical Signs .......................................................................... 130 27.5 Pathology ................................................................................ 131 27.6 Diagnosis ................................................................................ 131 27.7 Treatment ................................................................................ 131 27.8 Prevention ............................................................................... 132 ENTERIC DISEASES................................................................................ 133 28.0 COCCIDIOSIS .................................................................................... 134 28.1 Etiology................................................................................... 134 28.2 Occurrence and Economic Significance ................................. 134 28.3 Transmission ........................................................................... 134 28.4 Clinical Signs .......................................................................... 134 28.5 Lesions .................................................................................... 134 28.6 Diagnosis ................................................................................ 135 28.7 Treatment ................................................................................ 135 28.8 Prevention ............................................................................... 135 29.0 CLOSTRIDIAL ENTEROTOXEMIA ................................................ 138 29.1 Etiology................................................................................... 138 29.2 Occurrence and Economic Significance ................................. 138 29.3 Transmission ........................................................................... 138 29.4 Clinical Signs .......................................................................... 138 29.5 Pathology ................................................................................ 138 29.6 Diagnosis ................................................................................ 139 viii 29.7 Treatment ................................................................................ 139 29.8 Prevention ............................................................................... 139 30.0 ENDOPARASITES ............................................................................. 141 30.1 Capillariasis ............................................................................ 141 30.2 Ascaridiasis ............................................................................. 141 30.3 Cestodiasis .............................................................................. 141 LOCOMOTORY ABNORMALITIES ..................................................... 144 31.0 SKELETAL DEFORMITIES AND ARTHRITIS ............................... 145 31.1 Nutritional Etiology ................................................................ 145 31.2 Infectious etiology .................................................................. 146 31.2.1 Mycoplasmosis........................................................... 146 31.2.2 Reoviral Arthritis........................................................ 146 31.2.3 Staphylococcal Arthritis ............................................. 147 31.3 Pododermatitis ........................................................................ 148 31.3.1 Alleviation of Locomotory Problems Through Nutrition ..................................................................... 149 31.4 Developmental Etiology ......................................................... 152 31.4.1 Twisted Legs .............................................................. 152 31.4.2 Rotated Tibia and Crooked Toes ................................ 152 INTEGUMENTARY CONDITIONS........................................................ 153 32.0 AVIAN POX ........................................................................................ 154 32.1 Etiology. .................................................................................. 154 32.2 Occurrence and Economic Significance ................................. 155 32.3 Transmission ........................................................................... 154 32.4 Clinical Signs .......................................................................... 154 32.5 Pathology ................................................................................ 154 32.6 Diagnosis ................................................................................ 154 32.7 Prevention ............................................................................... 154 33.0 ECTOPARASITES .............................................................................. 156 33.1 Mites ....................................................................................... 156 33.2 Argasid Ticks .......................................................................... 156 33.3 Scaly Leg Mites ...................................................................... 156