Tail and ear necrosis in piglets of sows with increased weight loss over the suckling period.

INTRODUCTION
A farm belonging to a Swiss sow pool system reported increased cases of necrosis on the base of the tail or ears in their piglets. Therefore, herd examination was performed in February 2021, and it was found that about half of all examined litters included piglets with necrosis of different locations, and that the sows of these piglets were rather thin. Upon instruction, the farmer then documented the body condition score (BCS) and weight before farrowing and after weaning, and the number of liveborn piglets affected by necrosis of the tail or ear of the next four farrowing batches. In total, data of 97 sows with 1214 liveborn piglets were evaluated. Sows were retrospectively allocated into two groups: Those with piglets with ear and/or tail necrosis (NE), and those without (WN). Of the 97 litters, 40 included piglets with necrosis, with 28 of them having piglets only with tail necrosis, 8 only with ear necrosis, and 4 litters included piglets with both types of necrosis. The group NE lost significantly more weight and BCS points over the suckling period than the group WN, with a tendency of having a lower BCS after weaning (2,0 vs. 2,25/5,0). Blood samples of five sows were analyzed and tested positive for the Fusarium mycotoxin deoxynivalenol (DON). It could be possible that the sows previously consumed DON contaminated feed, which was then stored in their fat tissue, and released again into the blood stream during increased weight loss. Since DON can be transferred from the sow to her piglets during gestation or lactation, this release might have affected the piglets, leading to tail or ear necrosis. However, causative studies are needed to confirm this hypothesis.