Title Page
Contents
ABSTRACT 11
Ⅰ. Introduction 13
Ⅱ. Literature review 14
2.1. Background and purpose 14
2.2. What is animal welfare? 15
2.3. Assessment of animal welfare 16
2.4. Footpad dermatitis as an indicator for broiler welfare 17
2.4.1. Litter quality 18
2.4.2. Stocking density 18
2.4.3. Drinking system and feed 19
2.4.4. Genetics 19
2.4.5. Climate and ventilation 20
2.5. Hock burn as an indicator for broiler welfare 20
2.5.1. Litter quality 21
2.5.2. Body weight 21
2.5.3. Stocking density 22
2.5.4. Environmental factors 22
2.6. Feather cleanliness as an indicator for broiler welfare 23
2.6.1. Litter quality 23
2.6.2. Stocking density 24
2.6.3. Genetics 24
2.6.4. Environmental enrichment 24
2.7. Gait score as an indicator for broiler welfare 25
2.7.1. Genetics 26
2.7.2. Age and weight 26
2.7.3. Management practices 26
2.8. Conclusion 28
Ⅲ. Assessment of animal welfare status in the conventional and animal welfare certified broiler farms 29
Abstract 29
3.1. Introduction 31
3.2. Materials and methods 32
3.2.1. Birds and farms selection 32
3.2.2. Measurements and sampling 33
3.2.3. Statistical analysis 36
3.3. Results and discussion 42
3.3.1. Production parameters, body weight, and uniformity 42
3.3.2. Corticosterone concentrations 46
3.3.3. Footpad dermatitis, hock burn, and feather cleanliness score 48
3.3.4. Gait score 50
3.3.5. Litter quality 52
3.3.6. Light intensity and ammonia concentration 54
3.3.7. Body surface temperature 57
3.4. Conclusions 59
Ⅳ. Effects of environmental enrichment provision on productivity, welfare and physiological indicators of broilers raised in animal welfare certificated farms 60
Abstract 60
4.1. Introduction 61
4.2. Materials and methods 62
4.2.1. Birds and experimental farms 62
4.2.2. Pecking blocks 63
4.2.3. Research schedule and measurements 63
4.2.4. Statistical analysis 66
4.3. Results and discussion 71
4.3.1. Body weight and uniformity 71
4.3.2. Concentrations of corticosteroid in fecal droppings and feathers 73
4.3.3. Footpad dermatitis, hock burn, and feather cleanliness 75
4.3.4. Gait score 77
4.3.5. Litter quality 79
4.3.6. Body surface temperature 81
4.3.7. Volatile fatty acids in feces 83
4.4. Conclusion 85
Ⅴ. Effects of perch on productivity, welfare and physiological indicators of broilers reared in animal welfare certificated farms 86
Abstract 86
5.1. Introduction 87
5.2. Materials and methods 88
5.2.1. Birds and experimental farms 88
5.2.2. Perch 88
5.2.3. Research schedule and measurements 89
5.2.4. Statistical analysis 91
5.3. Results and discussion 96
5.3.1. Body weight and uniformity 96
5.3.2. Corticosterone concentration 98
5.3.3. Footpad dermatitis, hock burn, and feather cleanliness 100
5.3.4. Gait score 102
5.3.5. Litter quality 104
5.3.6. Body surface temperature 106
5.4. Conclusion 108
Ⅵ. Overall Discussion 109
References 112
Abstract (in Korean) 131
Table 3.1. Main characteristics of the experimental farms of conventional and animal welfare farms 37
Table 3.2. Bird welfare assessment parameters and number of samples 38
Table 3.3. Chemical composition of the experimental diets (dry matter basis) 39
Table 3.4. Production parameters of broiler chickens recorded between conventional and animal welfare systems 44
Table 3.5. Body weight and uniformity of 26-days-old broilers between conventional and animal welfare farms 45
Table 3.6. Corticosterone concentrations in broiler feces and feathers between conventional and animal welfare systems 47
Table 3.7. Percentage of footpad dermatitis, hock burn, and feather cleanliness score assessment results in the broiler chickens between conventional and animal... 49
Table 3.8. Percentage of gait score in broiler flocks between conventional and animal welfare systems 51
Table 3.9. Litter moisture, nitrogen, and pH in broiler chicken farm between conventional and animal welfare systems 53
Table 3.10. Light intensity and ammonia concentration in the house between conventional and animal welfare systems 56
Table 3.11. Body surface temperature in broiler chickens between conventional and animal welfare systems 58
Table 4.1. Main characteristics of the experimental farms 67
Table 4.2. Broiler welfare assessment parameters and number of samples 68
Table 4.3. Body weight and uniformity of 26-day-old broilers with or without enrichment 72
Table 4.4. Corticosterone concentrations in broiler feces and feathers with or without enrichment 74
Table 4.5. Percentage of footpad dermatitis, hock burn, and feather cleanliness score assessment results in the broiler chickens with or without enrichment 76
Table 4.6. Percentage of gait score in broiler flocks with or without the enrichment 78
Table 4.7. Litter moisture, nitrogen, and pH in broiler farmhouses with or without enrichment 80
Table 4.8. Body surface temperature in broiler chickens with or without enrichment 82
Table 4.9. Fecal volatile fatty acids in broiler chickens with or without enrichment 84
Table 5.1. Main characteristics of the experimental farms 92
Table 5.2. Broiler welfare assessment parameters and number of samples 93
Table 5.3. Body weight and uniformity of 26-day-old broilers with or without perch 97
Table 5.4. Corticosterone concentrations in broiler feces and feathers with or without perch 99
Table 5.5. Percentage of footpad dermatitis, hock burn, and feather cleanliness score assessment results in the broiler chickens with or without perch 101
Table 5.6. Percentage of gait score in broiler flocks with or without the perch 103
Table 5.7. Litter moisture, nitrogen, pH in broiler chicken farms with or without perch 105
Table 5.8. Body surface temperature in broiler chickens with or without perch 107
Figure 3.1. Scoring for footpad dermatitis, hock burn, and feather cleanliness. (A) Footpad dermatitis and (B) Hock burn were scored on a scale of 0 to 2 points, depending on the size and severity of the lesion.... 40
Figure 3.2. Schematic diagram of sampling locations of parameters in houses. Each symbol ('●' and '◇') represents a specific sampling location. '●' symbols indicate... 41
Figure 4.1. Grain block used in the experiment for enrichment. It is a block of 25 × 25 × 25 cm, mixed with a grain base in the form of a cube. The... 69
Figure 4.2. Schematic diagram of the sampling locations of parameters and placement of the enrichment in houses. The symbol '❒' represents the placement of enrichment (grain block), while the symbols '◆' and '●' represent specific sampling... 70
Figure 5.1. The figure of perch used in the experiment. The perch used in this experiment is a wooden square bar with a thickness of 2 × 2... 94
Figure 5.2. Schematic diagram of the sampling locations of parameters and placement of the perch in houses. The symbol '=' represents the placement of perch,... 95