Digital documentation of individual treatment data and its relation to veterinary slaughter lesions in pigs

Legislation in the European Union demands the documentation of on-farm treatments and the documentation of lesions found at slaughter. The fulfilment of these documentation duties in a digitalised form allows further interpretation of the data. The aim of this study was to use a digital system for the documentation of on-farm treatments to determine the status quo of a farm's health status. Furthermore, relations between individual treatments and lesions found at slaughter were investigated. The data were obtained between August 2020 and September 2022 from a combined pig farm in northern Germany using a digital tool to document treatment data and from the slaughterhouses to which the pigs were delivered. The majority of individual treatments were observed in the fattening unit with 42.4 % of all individual treatments, followed by the rearing unit (40.4 %) and the piglet production (17.2 %). The most frequent reason for individual treatments was locomotor system diseases in all units (45.5 to 47.4 %), which occurred throughout the whole time of data collection. Gastrointestinal diseases represented the second most frequent individual treatment reason in the piglet production. Runt pigs in the rearing unit appeared in peaks, while tail lesions in the fattening unit seemed to occur especially in the colder months of the year. 18.2 % individuals received individual treatments. At the slaughterhouse, lesions were recorded for 18.1 % of the individuals. Lesions of the respiratory tract were found in 15.5 % of the individuals. The relation between slaughter lesions and individual treatment data was investigated using logistic regression models. In comparison to individual pigs which did not receive individual treatments, for individuals which received individual treatments in the early stage of life an odds ratio (OR) $=$ 1.5 (95 % confidence interval (95 % CI): 1.2 to 2) and for individuals which received individual treatments in the later stage of life an OR $=$ 1.9 (95 % CI: 1.4 to 2.5) were obtained. To conclude, there were higher risks for individuals which received individual treatments in the early or later stage of life but not for those who received treatments in both stages of life. Digitalised data of treatments can bring value to pig farming in regards to the overview they can provide.