Long tails in pigs: an on farm risk-assessment-tool

Abstract

The objective of this study was to test and fine-tune the first version of the on farm risk-assessment-tool for biting behavior in pigs, developed by the steering committee of the project ‘Intact tails 2017-2021’. This tool was used for a risk assessment on thirteen pig farms in the Netherlands in 2018. The quality of the on farm risk-assessment-tool was assessed on the basis of the data obtained. The overall objective was broken down in two aims. The primary aim of this research was to examine to which extent animal-related indicators observations are associated with non-animal-related indicators observations in three age groups: suckling piglets, weaned piglets and fattening pigs/breeding gilts. Non-animal-related indicators are measurements in the pigs’ environment and include feed, space, climate, enrichment, hygiene and animal health. Animal-related indicators are measurements on the animal itself, such as body cleanliness, presence of an intact tail and body condition score. For four non-animal-related indicators in the category ‘feed’ in weaned piglets, it was examined whether there is an association with observations for the animal-related indicator 'tail intact end of rearing'. The second aim was to study the association of four non-animal-related indicators in the category feed of weaned pigs with the animal-related indicator ‘tail intact end of rearing’. This association has been studied for the thirteen network farms as well as for three farms outside the network. Each of these three farms had an anamnesis of tail biting problems and/or the farmer had the ambition to stop tail docking. In addition to these two main objectives, several recommendations for optimization of the design of the on farm risk-assessment-tool were formulated. The results of the study indicate a strong, significant positive relationship between the percentage of deviating non-animal-related indicators and deviating animal-related indicators in the age groups of suckling piglets and weaned piglets. However, this did not apply to the age group of finishing pigs/breeding gilts; a weak positive but not significant association was found there. Regarding the category ‘feed’ of weaned piglets insufficient data was available to make a statement about a possible association between four separate non-animal-related indicators in relation to the animal-related indicator ‘intact tail end of rearing'. In conclusion, the on farm risk-assessment-tool is usable and sufficiently reliable to identify risk factors for tail biting at farm level for suckling piglets and weaned piglets. It is recommended to expand the dataset of completed risk-assessment-tools, so that a potential trend in individual animal- and non-animal-related indicators can be clarified.