Compressed Brown Algae as a Potential Environmental Enrichment Material in Growing Pigs

SIMPLE SUMMARY: To prevent pigs from redirecting their exploratory natural behavior to their penmates, so as to prevent tail biting and promote pig welfare, the Council Directive 2008/120/EC has made environmental enrichment in pig farming mandatory. Possible enrichments can be varied: objects that are edible or not or bulk material. However, the enrichments need to be compatible with slatted floors, the main type of floor in pig housing. Here, we assessed the impact on pig welfare of a material made of an algae-based cylinder, compatible with slatted floors and edible, and which is categorized as suboptimal enrichment materials according to Commission Recommendation (EU) 2016/336 classification. The assessment was done in comparison with metal chains, an enrichment material commonly used in farms, and with wood logs, a bio-sourced object too. Enrichment material made from algae had no negative effect on pig health. Performance and body condition were similar between groups that were given different materials. When provided during the suckling period, the algae material did not appear to promote manipulating behavior in piglets after weaning. Regarding their characteristics, the algae cylinders can be categorized as suboptimal enrichment materials, although it does not significantly improve pig welfare when compared to a metal chain, which is categorized as a material of marginal interest. ABSTRACT: In barren housing conditions, enrichment materials are given to pigs to improve their welfare. Here, we assessed the suitability of an algae-based cylinder as an enrichment material on the behavioral, physiological, health and productivity welfare indicators of pigs. Algae was compared with metal chains and wood logs. The study involved 444 pigs from two successive batches on one single farm. During the suckling period, half of the pigs received algae and the control pigs received no material. After weaning and until the end of fattening, algae, wood or chains were equally distributed among the pigs. Consumption of algae cylinders was different between pens and between batches. After weaning and during the fattening period, although the results differed between batches, no significant difference was observed in the object manipulations. Salivary cortisol, used as biomarker to measure the stress levels after pig transfers, were similar between the treatments. Enrichment material made from algae had no negative effect on pig health and no effect on performance and body condition. Regarding their characteristics and according to Commission Recommendation (EU) 2016/336 classification, algae cylinders can be categorized as suboptimal enrichment materials, although the present results suggest that it does not significantly improve pig welfare compared to a metal chain, which is categorized as a material of marginal interest.