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Research Note: Toe Scratches Cause Scabby Hip Syndrome Lesions
RESEARCH NOTES Research Note: Toe Scratches Cause Scabby Hip Syndrome Lesions B. M. HARGIS, 1 ' 2 R. W. MOORE,2 and A. R. SAMS2 Department of Veterinary Microbiology and Parasitology and Department of Poultry Science, Texas Agricultural Experiment Station, Texas A&M University System, College Station, Texas 77843 (Received for publication October 5, 1988)
1989 Poultry Science 68:1148-1149 INTRODUCTION
Scabby hip syndrome has become a major problem for the broiler industry, often resulting in substantial downgrading and trimming at the processing plant (Page, 1974). Stocking density and other factors, such as warm humid environments, high ammonia levels, and old litter, have been occasionally observed to be associated with the incidence and severity of the skin lesions (Peterson, 1974; Harris, 1977; Harris et ah, 1978; Proudfoot and Hulan, 1985). Clinical observations have indicated that over 70% of scabby hip lesions may be associated with traumatic excoriations or scratches, and that the majority of these scratches are located on the caudal dorsal convexity of the carcasses (Hargis et al., 1988). Furthermore, one recent study failed to identify any common bacteriologic etiology associated with these lesions (Scanlan and Hargis, 1988). The gross appearance of the majority of the lesions has indicated that the most likely cause of the wounds is toe scratches from birds climbing on one another. These studies were conducted to investigate the effect of partial detoeing on the develop-
ment and severity of the lesions of scabby hip syndrome. MATERIALS AND METHODS
Two commercial broiler houses at separate farms staffed with different personnel (Sites A and B) were divided into equal halves by placing a screen wire division across the short axis of each house. Each half received either normal or detoed commercial run broilers. Chicks were detoed prior to placement by removal of approximately two-thirds of the distal phalanx of each digit with a commercial, poult detoeing blade. An average of 1.5 toes/ bird (Site A) and .6 toes/bird (Site B) were intact at processing. Total birds placed at Site A were 3,500 and at Site B were 4,275. Placement densities of .70 ft2 (.063 m 2 , Site A) and .68 ft2 (.061 m 2 , Site B) were equal for each half of the same house. Fifty, fully toed birds (control) and 50 detoed birds were processed and subjectively scored (Table 1) for scabby hip lesions at 36 days of age (Site A) and 29 days of age (Site B). Four hundred control and 400 detoed birds were also scored following commercial processing at 50 days of age. The data were analyzed by a one-way ANOVA within sites and ages. RESULTS AND DISCUSSION
Department of Veterinary Microbiology and Parasitology;2
Department of Poultry Science.
The effect of toe removal prior to chick placement on scabby hip scores for each 1148
Downloaded from http://ps.oxfordjournals.org/ at UCSF Library on April 17, 2015
ABSTRACT Scabs and scratches in the hip region of chicken carcasses have become the single most common cause of downgrading and required trimming at processing in some areas of the United States. Repeatable correlations with microbiological agents, environment, and nutrition have not been observed. The present report provides evidence that scabs and scratches, present at processing, are the result of injuries inflicted by toenails of birds as they climb on one another. Onychectomy (removal of approximately twothirds of the distal phalanx) of all four digits of each foot prior to chick placement resulted in 3.7 and 4.8-fold reductions in subjective lesion scores and 7 to 10-fold increases in the percentage of USDA Grade A carcasses at a commercial processing plant. (Key words: scabby hip syndrome, scabs, scratches, detoeing)
1149
RESEARCH NOTE TABLE 1. Summary of scabby hip scores Site
Treatment
Age
Score
A A A A B B B B
Control Detoed Control Detoed Control Detoed Control Detoed
(days) 36 36 50 50 29 29 50 50
2.4 .50 2.8 .75 2.5 .26 3.5 1.3
± ± ± ± ± ± ± ±
n .20 .12* .06 .06* .16 .08* .03 .07*
50 50 400 400 47 50 400 400
REFERENCES
experiment is summarized in Table 1. At Site A, toe removal resulted in a mean lesion score for treated birds of .50 vs. a score of 2.4 for their intact counterparts, at 36 days of age. By the time of commercial processing (50 days), the severity of the lesions had increased slightly to a mean score of 2.7 for the control birds and only .75 for the detoed birds. Similarly, at Site B detoeing resulted in a significant reduction in lesion scores at 29 days and at processing. Furthermore, detoeing resulted in a seven to ten-fold increase in USDA Grade A carcasses at the time of commercial processing in these experiments. Evidence indicates that the primary cause of scabs, scratches, and wounds related to scabby hips is injury inflicted by the toenails of broilers climbing on one another. The gross
Hargis, B. M , C. M. Scanlan, and S. H. Poythress, 1988. Clinical, microbiological and histopathological observations in scabby-hip syndrome in Texas broilers. Page 47 in: Proc. 29th South. Conf. Avian Dis. Harris, G. C, 1977. Nutrition, bird density and litter effects on scabby-hip (dermatitis) of broilers. Pages 42-44 in: Proc. Delmarva Poultry Health Conf. Harris, G. C , Jr., M. Musbah, and J. N. Beasley, 1978. The development of dermatitis (scabby-hip) of the hip and thigh of broiler chickens. Avian Dis. 22:122-130. Page, R. K., 1974. Scabby hip disease in broilers. Poult. Dig., October, pages 431-432. Peterson, E. H., 1974. A condition of bone degeneration in chickens and its possible relation to so-called "scabby" hip. Poultry Sci. 53:822-824. Proudfoot, F. G., and H. W. Halaw, 1985. Effect of stocking density on the incidence of scabby-hip syndrome among broiler chickens. Poultry Sci. 64:2001-2003. Scanlan, C. M, and B. M. Hargis, 1989. A bacteriologic study of scabby-hip lesions from broiler chickens in Texas. J. Vet. Diag. Invest. 1:170-173.
Downloaded from http://ps.oxfordjournals.org/ at UCSF Library on April 17, 2015
^core (x ± SD); 0 = no skin lesions (bruises or processing damage was not scored); 1 = one superficial scratch or scab; 2 = two superficial scratches or scabs; 3 = three superficial scratches or scabs or one deep wound (deep wounds are defined as complete penetration of the dermis); 4 = multiple deep wounds or one deep wound with multiple superficial scratches or scabs. *P<.05 from control.
observation reveals that the majority of these injuries present as linear scratches and that they are oriented in a general dorsal to ventral direction. Second, no consistent microbiological cause of these skin lesions has been identified (Scanlan and Hargis, 1988). Third, as can be observed in the data presented here, reduction in the number of toes results in a substantial reduction in the number of scabs and scratches. Complete detoeing of all production broilers is not advocated at this time. The primary purpose of these studies was to identify the cause of scabby hips. Measures to reduce the incidence of skin lesions in production broilers may include selective detoeing and in some cases reduction of bird placement density. The effectiveness of removal of selected toes remains to be evaluated.
1989 Poultry Science 68:1148-1149 INTRODUCTION
Scabby hip syndrome has become a major problem for the broiler industry, often resulting in substantial downgrading and trimming at the processing plant (Page, 1974). Stocking density and other factors, such as warm humid environments, high ammonia levels, and old litter, have been occasionally observed to be associated with the incidence and severity of the skin lesions (Peterson, 1974; Harris, 1977; Harris et ah, 1978; Proudfoot and Hulan, 1985). Clinical observations have indicated that over 70% of scabby hip lesions may be associated with traumatic excoriations or scratches, and that the majority of these scratches are located on the caudal dorsal convexity of the carcasses (Hargis et al., 1988). Furthermore, one recent study failed to identify any common bacteriologic etiology associated with these lesions (Scanlan and Hargis, 1988). The gross appearance of the majority of the lesions has indicated that the most likely cause of the wounds is toe scratches from birds climbing on one another. These studies were conducted to investigate the effect of partial detoeing on the develop-
ment and severity of the lesions of scabby hip syndrome. MATERIALS AND METHODS
Two commercial broiler houses at separate farms staffed with different personnel (Sites A and B) were divided into equal halves by placing a screen wire division across the short axis of each house. Each half received either normal or detoed commercial run broilers. Chicks were detoed prior to placement by removal of approximately two-thirds of the distal phalanx of each digit with a commercial, poult detoeing blade. An average of 1.5 toes/ bird (Site A) and .6 toes/bird (Site B) were intact at processing. Total birds placed at Site A were 3,500 and at Site B were 4,275. Placement densities of .70 ft2 (.063 m 2 , Site A) and .68 ft2 (.061 m 2 , Site B) were equal for each half of the same house. Fifty, fully toed birds (control) and 50 detoed birds were processed and subjectively scored (Table 1) for scabby hip lesions at 36 days of age (Site A) and 29 days of age (Site B). Four hundred control and 400 detoed birds were also scored following commercial processing at 50 days of age. The data were analyzed by a one-way ANOVA within sites and ages. RESULTS AND DISCUSSION
Department of Veterinary Microbiology and Parasitology;2
Department of Poultry Science.
The effect of toe removal prior to chick placement on scabby hip scores for each 1148
Downloaded from http://ps.oxfordjournals.org/ at UCSF Library on April 17, 2015
ABSTRACT Scabs and scratches in the hip region of chicken carcasses have become the single most common cause of downgrading and required trimming at processing in some areas of the United States. Repeatable correlations with microbiological agents, environment, and nutrition have not been observed. The present report provides evidence that scabs and scratches, present at processing, are the result of injuries inflicted by toenails of birds as they climb on one another. Onychectomy (removal of approximately twothirds of the distal phalanx) of all four digits of each foot prior to chick placement resulted in 3.7 and 4.8-fold reductions in subjective lesion scores and 7 to 10-fold increases in the percentage of USDA Grade A carcasses at a commercial processing plant. (Key words: scabby hip syndrome, scabs, scratches, detoeing)
1149
RESEARCH NOTE TABLE 1. Summary of scabby hip scores Site
Treatment
Age
Score
A A A A B B B B
Control Detoed Control Detoed Control Detoed Control Detoed
(days) 36 36 50 50 29 29 50 50
2.4 .50 2.8 .75 2.5 .26 3.5 1.3
± ± ± ± ± ± ± ±
n .20 .12* .06 .06* .16 .08* .03 .07*
50 50 400 400 47 50 400 400
REFERENCES
experiment is summarized in Table 1. At Site A, toe removal resulted in a mean lesion score for treated birds of .50 vs. a score of 2.4 for their intact counterparts, at 36 days of age. By the time of commercial processing (50 days), the severity of the lesions had increased slightly to a mean score of 2.7 for the control birds and only .75 for the detoed birds. Similarly, at Site B detoeing resulted in a significant reduction in lesion scores at 29 days and at processing. Furthermore, detoeing resulted in a seven to ten-fold increase in USDA Grade A carcasses at the time of commercial processing in these experiments. Evidence indicates that the primary cause of scabs, scratches, and wounds related to scabby hips is injury inflicted by the toenails of broilers climbing on one another. The gross
Hargis, B. M , C. M. Scanlan, and S. H. Poythress, 1988. Clinical, microbiological and histopathological observations in scabby-hip syndrome in Texas broilers. Page 47 in: Proc. 29th South. Conf. Avian Dis. Harris, G. C, 1977. Nutrition, bird density and litter effects on scabby-hip (dermatitis) of broilers. Pages 42-44 in: Proc. Delmarva Poultry Health Conf. Harris, G. C , Jr., M. Musbah, and J. N. Beasley, 1978. The development of dermatitis (scabby-hip) of the hip and thigh of broiler chickens. Avian Dis. 22:122-130. Page, R. K., 1974. Scabby hip disease in broilers. Poult. Dig., October, pages 431-432. Peterson, E. H., 1974. A condition of bone degeneration in chickens and its possible relation to so-called "scabby" hip. Poultry Sci. 53:822-824. Proudfoot, F. G., and H. W. Halaw, 1985. Effect of stocking density on the incidence of scabby-hip syndrome among broiler chickens. Poultry Sci. 64:2001-2003. Scanlan, C. M, and B. M. Hargis, 1989. A bacteriologic study of scabby-hip lesions from broiler chickens in Texas. J. Vet. Diag. Invest. 1:170-173.
Downloaded from http://ps.oxfordjournals.org/ at UCSF Library on April 17, 2015
^core (x ± SD); 0 = no skin lesions (bruises or processing damage was not scored); 1 = one superficial scratch or scab; 2 = two superficial scratches or scabs; 3 = three superficial scratches or scabs or one deep wound (deep wounds are defined as complete penetration of the dermis); 4 = multiple deep wounds or one deep wound with multiple superficial scratches or scabs. *P<.05 from control.
observation reveals that the majority of these injuries present as linear scratches and that they are oriented in a general dorsal to ventral direction. Second, no consistent microbiological cause of these skin lesions has been identified (Scanlan and Hargis, 1988). Third, as can be observed in the data presented here, reduction in the number of toes results in a substantial reduction in the number of scabs and scratches. Complete detoeing of all production broilers is not advocated at this time. The primary purpose of these studies was to identify the cause of scabby hips. Measures to reduce the incidence of skin lesions in production broilers may include selective detoeing and in some cases reduction of bird placement density. The effectiveness of removal of selected toes remains to be evaluated.