Evaluation of welfare management and environmental enrichments in broiler farms = 육계 농장의 동물복지 사육 방법 및 환경풍부화물의 적용 평가

국문 초록 (Abstract)

본 연구는 기존에 개발된 동물 복지 평가 기준을 바탕으로 상업용 육계 농장의 복지 수준을 조사하고 복지 개선 물질이 생산성과 복지지표에 미치는 효과를 조사하기 위하여 세 가지 실험을 수행하였다. 실험1에서는 국내 인접한 육계 관행사육 농장 1곳과 동물복지 인증 농장 1곳을 선정하여 여름철과 가을철의 26일령 육계 생산성, 복지지표, 생리적 지표 등을 비교 분석하였다. 그 결과 체중은 가을철에 동물복지 인증농장에서 유의하게 높았으나(P = 0.044), 여름철 체중 및 균일도, 가을철 체중에는 차이가 없었다. 분변 코르티코스테론 농도를 분석한 결과, 여름과 가을 모두 동물복지농장에서 유의하게 높은 결과를 보였고(P < 0.001), 깃털 코르티코스테론은 가을에만 동물복지 인증농가에서 더 높은 경향이 나타났다(P = 0.071). 여름철 두 농장 발바닥 피부염과 깃털청결도는 차이가 없었으나, 비절 피부염은 관행사육농장에서 유의하게 부정적인 결과를 보였다(P = 0.002). 가을철에는 세 지표 모두에서 차이가 더 커졌다. 보행점수는 통계적으로 유의한 차이는 발견되지 않았다. 여름철 깔짚의 질소 함량은 관행사육농장에서 높은 경향을 보였고(P = 0.055), 수분과 pH는 차이가 없었다. 동물복지농장이 관행사육농장보다 여름철(P = 0.003) 및 가을철(P < 0.001) 모두 조도가 밝은 것으로 나타났으며, 암모니아 농도 차이는 없었다. 머리의 체표면 온도는 동물복지농장에서 여름철에 유의하게 높았고(P = 0.017), 관행사육농장은 가을철에 머리(P = 0.005)와 다리(P = 0.002)에서 유의하게 높았다. 실험2는 국내 동물복지 축산농장 인증을 받은 육계 사육 농가 2개소를 대상으로 곡물 베이스로 된 쪼는 물체의 환경풍부화물이 육계의 생산성 및 동물복지 수준에 어떠한 영향을 미치는지 조사하고자 실험을 수행하였다. 실험에 적용한 쪼는 물체는 곡물 블록으로서 25×25×25 cm 로 정육면체 형태로 배합된 블록이며 처리구에 1000수 당 1개씩 제공하여 실험을 진행하였다. 실험 결과 농장 A와 B의 26일령 체중과 체중의 균일도, 분변 및 깃털 코르티코스테론, 동물 기반 동물복지 지표(발바닥 피부염, 비절 화상, 깃털청결도, 보행 점수), 깔짚 품질(수분, 질소, pH)에서 처리구간 유의한 차이가 나타나지 않았다. 체표면 온도는 머리, 가슴, 다리 부분을 측정하여 분석한 결과 농장 A에서 환경풍부화물 처리구의 머리(P = 0.029)와 다리(P = 0.011) 체표면 온도가 유의적으로 높게 나타났으며, 농장 B는 처리구간 차이가 없었다. 분변의 휘발성지방산(VFA)의 정량 분석과 비율을 분석한 결과 농장 A에서는 처리구 간 유의차가 나타나지 않았으나, 농장 B에서는 butyrate의 비율이 환경풍부화물 처리구에서 유의적으로 높게 나타나(P = 0.023), 곡물 블록의 사용이 육계 장 건강에도 긍정적인 영향을 줄 수 있는 가능성을 확인하였다. 실험3에서는 국내 동물복지축산농장 인증을 받은 육계농장에서 횃대가 육계의 생산성과 동물복지 수준에 어떤 영향을 미치는지 알아보기 위해 가을철(10월), 봄철(3~4월), 봄철(5~6월)에 실험을 수행하였다. 실험에 사용한 횃대는 나무로 된 2×2 cm 의 각목 횃대이며, 처리구에 1000수 당 2미터씩 제공하여 실험을 진행하였다. 그 결과 생산성(체중 및 균일도)과 깔짚 품질(수분, 질소, pH)은 농장별, 계절별로 일관되지 않은 결과를 보였다. 스트레스의 생리학적 지표인 코르티코스테론은 A농장에서는 깃털과 분변 모두 유의한 차이가 없었지만, B농장에서는 분변 코르티코스테론이 횃대 처리구에서 유의하게 더 낮았다(P = 0.001). 동물 복지 지표(발바닥 피부염, 무릎 화상, 깃털 청결도, 보행 점수)에서는 두 농가 모두 유의한 차이가 없었다. 본 연구결과 육계의 생산성과 복지지표는 일반 관행농장과 복지 인증농가 간 큰 차이가 없는 것으로 조사되었다. 횃대나 쪼는 물질과 같은 환경풍부화물은 동물복지 지표에 효과를 나타났으나 일관적이지는 않았다.

다국어 초록 (Multilingual Abstract)

This study was investigated to evaluate on welfare status in broiler farms based on previously developed animal welfare assessment criteria and was conducted experiments to investigate the effects of such as environmental enrichments. In Experiment 1, one conventional broiler farm and one animal welfare certified farm were selected to conduct a comparative analysis of productivity, welfare indicators, and physiological indices during summer and autumn. The results showed that in autumn, the weight was significantly higher in animal welfare certified farms (P = 0.044), and there was no difference in weight and uniformity between summer and autumn. Fecal corticosterone concentration was significantly higher in animal welfare farms in both summer and autumn (P < 0.001), and feather corticosterone tended to be higher in animal welfare certified farms only in autumn (P = 0.071). There was no difference in plantar dermatitis and feather cleanliness at the two farms in summer, but a significantly negative result was shown for hock burns in the conventional farm (P = 0.002). The gait score showed no statistically significant difference. The nitrogen content of litter in summer tended to be higher in the conventional farm (P = 0.055), and there was no difference in moisture and pH. Animal welfare farm was found to be brighter than conventional farm in summer (P = 0.003) and autumn (P < 0.001), and there was no difference in ammonia concentration. The body surface temperature of the head was significantly higher in summer of the animal welfare farm (P = 0.017), and significantly higher in both the head (P = 0.005) and legs (P = 0.002) in the autumn of the conventional farm. Overall, the study found that the conventional system had relatively negative results for welfare indicators. In Experiment 2, two commercial broiler farms that had been certified as animal welfare livestock farms were studied to investigate the effects of grain-based pecking material on productivity and animal welfare level of broilers. The experiment involved using a grain block as the pecking object, which was a 25 × 25 × 25 cm cube block provided at a rate of one per 1000 birds. The experiment analyzed 26-day-old body weight and body weight uniformity, fecal and feather corticosterone, animal-based welfare indicators (footpad dermatitis, hock burn, feather cleanliness, and gait score), and litter quality (moisture, nitrogen, and pH) in Farm A and B, finding no significant differences between treatments. Providing grain block at Farm A showed significantly higher body surface temperature of the head (P = 0.029) and legs (P = 0.011), whereas there was no difference in treatments at Farm B. Volatile fatty acids (VFA) in feces showed no significant difference between treatment groups in Farm A, but in Farm B, the ratio of butyrate was significantly higher in the grain block treatment (P = 0.023), indicating the potential positive effect of using grain blocks on broiler health. Experiment 3 aimed to investigate the impact of perches on the productivity and animal welfare of broilers in commercial broiler farms certified as animal welfare livestock farms during different seasons (autumn, spring, and early summer). Wooden perches were provided at a rate of 2 meters per 1000 birds. The results found inconsistent effects on productivity (weight and uniformity) and litter quality (moisture, nitrogen, and pH) depending on the farm and season. Corticosterone, a physiological stress indicator, showed no significant difference between feathers and feces in Farm A, while fecal corticosterone was significantly lower in the perch treatment at Farm B (P = 0.001). Animal welfare indicators (footpad dermatitis, hock burns, feather cleanliness, and gait score) showed no significant differences between the two farms. It is concluded that broilers raised in conventional or welfare-certified farms were performed well and exhibited higher standards of welfare status. In addition, environmental enrichment such as grain blocks or perches had positive effects on welfare status of broilers, but were inconsistent.

목차 (Table of Contents)

• Ⅰ. Introduction 1
• Ⅱ. Literature review 2
• 2.1. Background and purpose 2
• 2.2. What is animal welfare 3
• 2.3. Assessment of animal welfare 4
• 2.4. Footpad dermatitis as an indicator for broiler welfare assessment 5
• 2.4.1. Litter quality 6
• 2.4.2. Stocking density 6
• 2.4.3. Drinking system and feed 7
• 2.4.4. Genetics 7
• 2.4.5. Climate and ventilation 8
• 2.5. Hock burn as an indicator for broiler welfare assessment 8
• 2.5.1. Litter quality 9
• 2.5.2. Body weight 9
• 2.5.3. Stocking density 10
• 2.5.4. Environmental factors 10
• 2.6. Feather cleanliness as an indicator for broiler welfare assessment 11
• 2.6.1. Litter quality 11
• 2.6.2. Stocking density 12
• 2.6.3. Genetics 12
• 2.6.4. Environmental enrichment 12
• 2.7. Gait score as an indicator for broiler welfare assessment 13
• 2.7.1. Genetics 14
• 2.7.2. Age and weight 14
• 2.7.3. Management practices 14
• 2.8. Conclusion 16
• Ⅲ. Assessment of animal welfare status in the conventional and animal welfare certified broiler farms 17
• Abstract 17
• 3.1. Introduction 19
• 3.2. Materials and methods 20
• 3.2.1. Birds and farms selection 20
• 3.2.2. Measurements and sampling 21
• 3.2.3. Statistical analysis 24
• 3.3. Results and discussion 30
• 3.3.1. Production parameters, body weight, and uniformity 30
• 3.3.2. Corticosterone concentrations 34
• 3.3.3. Footpad dermatitis, hock burn, and feather cleanliness score 36
• 3.3.4. Gait score 38
• 3.3.5. Litter quality 40
• 3.3.6. Light intensity and ammonia concentration 42
• 3.3.7. Body surface temperature 45
• 3.4. Conclusions 47
• Ⅳ. Effects of environmental enrichment provision on productivity, welfare and physiological indicators of broilers raised in animal welfare certificated farms 48
• Abstract 48
• 4.1. Introduction 49
• 4.2. Materials and methods 50
• 4.2.1. Birds and experimental farms 50
• 4.2.2. Pecking blocks 51
• 4.2.3. Research schedule and measurements 51
• 4.2.4. Statistical analysis 54
• 4.3. Results and discussion 59
• 4.3.1. Body weight and uniformity 59
• 4.3.2. Concentrations of corticosteroid in fecal droppings and feathers 61
• 4.3.3. Footpad dermatitis, hock burn, and feather cleanliness 63
• 4.3.4. Gait score 65
• 4.3.5. Litter quality 67
• 4.3.6. Body surface temperature 69
• 4.3.7. Volatile fatty acids in feces 71
• 4.4. Conclusion 73
• Ⅴ. Effects of perch on productivity, welfare and physiological indicators of broilers reared in animal welfare certificated farms 74
• Abstract 74
• 5.1. Introduction 75
• 5.2. Materials and methods 76
• 5.2.1. Birds and experimental farms 76
• 5.2.2. Perch 76
• 5.2.3. Research schedule and measurements 77
• 5.2.4. Statistical analysis 79
• 5.3. Results and discussion 84
• 5.3.1. Body weight and uniformity 84
• 5.3.2. Corticosterone concentration 86
• 5.3.3. Footpad dermatitis, hock burn, and feather cleanliness 88
• 5.3.4. Gait score 90
• 5.3.5. Litter quality 92
• 5.3.6. Body surface temperature 94
• 5.4. Conclusion 96
• Ⅵ. Overall Discussion 97
• References 100
• Abstract (in Korean) 119

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