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Scoring tail damage in pigs: an evaluation based on recordings at Swedish slaughterhouses.

Keeling LJ, Wallenbeck A, Larsen A, Holmgren N - Acta Vet. Scand. (2012)

Bottom Line: However, it is difficult to draw conclusions when comparing prevalence's between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage.The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively.A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden. Linda.Keeling@slu.se

ABSTRACT

Background: There is increasing interest in recording tail damage in pigs at slaughter to identify problem farms for advisory purposes, but also for benchmarking within and between countries as part of systematic monitoring of animal welfare. However, it is difficult to draw conclusions when comparing prevalence's between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage.

Methods: Tail damage and tail length was recorded for 15,068 pigs slaughtered during three and four consecutive days at two slaughterhouses in Sweden. Tail damage was visually scored according to a 6-point scale and tail length was both visually scored according to a 5-point scale and recorded as tail length in centimetres for pigs with injured or shortened tails.

Results: The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively. When only considering pigs with half or less of the tail left, these percentages were 1.5% and 1.9%, which is in line with the prevalence estimated from the routine recordings at slaughter in Sweden. A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females.

Conclusions: While the current method to record tail damage in Sweden was found to be reliable as a method to identify problem farms, it clearly underestimates the actual prevalence of tail damage. For monitoring and benchmarking purposes, both in Sweden and internationally, we propose that a three graded scale including both old and new tail damage would be more appropriate. The scale consists of one class for no tail damage, one for mild tail damage (injured or shortened tail with more than half of the tail remaining) and one for severe tail damage (half or less of the tail remaining).

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Suggested tail damage scale classes (no, minor and major damage) for benchmarking purposes in practice, based on tail length and injury scores used in research. If pigs have more than half of the tail docked, using only the tail injury score (no injury and injury) could be considered. This would have the effect of no longer distinguishing between minor and major damage, but would still allow comparisons with non-tail docked pigs in the percentage of pigs with no damage and therefore still be useful for benchmarking internationally.
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Figure 1: Suggested tail damage scale classes (no, minor and major damage) for benchmarking purposes in practice, based on tail length and injury scores used in research. If pigs have more than half of the tail docked, using only the tail injury score (no injury and injury) could be considered. This would have the effect of no longer distinguishing between minor and major damage, but would still allow comparisons with non-tail docked pigs in the percentage of pigs with no damage and therefore still be useful for benchmarking internationally.

Mentions: Despite training of observers in the present study, the more detailed scoring of tail injury (6-point scale) and tail length (5-point scale) was not reliable when different observers were involved. This finding, together with the fact that there is a variation in routine recording between slaughterhouses [3] emphasizes the importance of a simple scoring system for routine slaughterhouse coding. To include the aspects of both underestimation of prevalence and observer reliability in a scale of tail damage at slaughter for benchmarking purposes, we suggest a three graded scale where both tail injury and tail length judgments evaluated in this study are included; one class for no tail damage, one intermediate class for mild tail damage, i.e. injured and/or shortened tail with more than half of the tail remaining, and one class for severe tail damage and/or less than half of the tail remaining (Figure 1). This scale combines information on the presence of new or old wounds on the tail by incorporating information on tail length. In this way all injuries, even completely healed ones, are included. Although we developed this scale at a slaughterhouse, the scoring system could also be used on-farm. If this scale is to be used in future, pictures illustrating the different scores would need to be agreed upon. Indeed if pictures had been used in this study, the slight difference in scoring between observers may have been reduced.


Scoring tail damage in pigs: an evaluation based on recordings at Swedish slaughterhouses.

Keeling LJ, Wallenbeck A, Larsen A, Holmgren N - Acta Vet. Scand. (2012)

Suggested tail damage scale classes (no, minor and major damage) for benchmarking purposes in practice, based on tail length and injury scores used in research. If pigs have more than half of the tail docked, using only the tail injury score (no injury and injury) could be considered. This would have the effect of no longer distinguishing between minor and major damage, but would still allow comparisons with non-tail docked pigs in the percentage of pigs with no damage and therefore still be useful for benchmarking internationally.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3405441&req=5

Figure 1: Suggested tail damage scale classes (no, minor and major damage) for benchmarking purposes in practice, based on tail length and injury scores used in research. If pigs have more than half of the tail docked, using only the tail injury score (no injury and injury) could be considered. This would have the effect of no longer distinguishing between minor and major damage, but would still allow comparisons with non-tail docked pigs in the percentage of pigs with no damage and therefore still be useful for benchmarking internationally.
Mentions: Despite training of observers in the present study, the more detailed scoring of tail injury (6-point scale) and tail length (5-point scale) was not reliable when different observers were involved. This finding, together with the fact that there is a variation in routine recording between slaughterhouses [3] emphasizes the importance of a simple scoring system for routine slaughterhouse coding. To include the aspects of both underestimation of prevalence and observer reliability in a scale of tail damage at slaughter for benchmarking purposes, we suggest a three graded scale where both tail injury and tail length judgments evaluated in this study are included; one class for no tail damage, one intermediate class for mild tail damage, i.e. injured and/or shortened tail with more than half of the tail remaining, and one class for severe tail damage and/or less than half of the tail remaining (Figure 1). This scale combines information on the presence of new or old wounds on the tail by incorporating information on tail length. In this way all injuries, even completely healed ones, are included. Although we developed this scale at a slaughterhouse, the scoring system could also be used on-farm. If this scale is to be used in future, pictures illustrating the different scores would need to be agreed upon. Indeed if pictures had been used in this study, the slight difference in scoring between observers may have been reduced.

Bottom Line: However, it is difficult to draw conclusions when comparing prevalence's between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage.The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively.A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden. Linda.Keeling@slu.se

ABSTRACT

Background: There is increasing interest in recording tail damage in pigs at slaughter to identify problem farms for advisory purposes, but also for benchmarking within and between countries as part of systematic monitoring of animal welfare. However, it is difficult to draw conclusions when comparing prevalence's between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage.

Methods: Tail damage and tail length was recorded for 15,068 pigs slaughtered during three and four consecutive days at two slaughterhouses in Sweden. Tail damage was visually scored according to a 6-point scale and tail length was both visually scored according to a 5-point scale and recorded as tail length in centimetres for pigs with injured or shortened tails.

Results: The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively. When only considering pigs with half or less of the tail left, these percentages were 1.5% and 1.9%, which is in line with the prevalence estimated from the routine recordings at slaughter in Sweden. A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females.

Conclusions: While the current method to record tail damage in Sweden was found to be reliable as a method to identify problem farms, it clearly underestimates the actual prevalence of tail damage. For monitoring and benchmarking purposes, both in Sweden and internationally, we propose that a three graded scale including both old and new tail damage would be more appropriate. The scale consists of one class for no tail damage, one for mild tail damage (injured or shortened tail with more than half of the tail remaining) and one for severe tail damage (half or less of the tail remaining).

Show MeSH
Related in: MedlinePlus