The new study is authored by Alessia Diana, Laura Ann Boyle, Edgar García Manzanilla, Finola Catherine Leonard and Julia Adriana Calderón Díaz from the Teagasc Animal and Grassland Research and Innovation Centre, Cork, and the School of Veterinary Medicine at the University College Dublin.

The study investigated the association between production flow and tail, ear and skin lesions on a farm with an ‘all-in/all-out’ policy. The study was purely observational meaning pigs were managed according to routine farm practice - no treatment was administered and there were no changes to husbandry as part of the investigation.

A total of 1,016 pigs born within 1 week from the same batch were followed through the production stages and the presence or absence of welfare indicators was recorded at 4, 7, 9, 12, 16 and 24 weeks of age.

Three production flows were retrospectively identified:

• flow one = ‘normal’ pigs that advanced through the production stages together ‘on time’;
• flow two = pigs delayed from advancing from the 1^st to the 2^nd nursery stage by 1 week; and
• flow three = pigs delayed from advancing through the production stages by > 1 week.

The trial results show:

• The presence of ear lesions was highest in pigs in flow one, with pigs in flow two 4.5 times less likely to have ear lesions compared to flow one.
• Pigs in flow one and flow three were more likely to have tail lesions compared to flow two.
• The risk of skin lesions being present was dictated mostly by pig age in each production flow.

The study concluded that all production flows were associated with a high risk of lesions to ears, tails and skin, which raises concerns for pig welfare. Risks for lesions varied according to each production flow and the researchers believe this is likely due to the specific management practices inherent to each flow.