Grouping of sows is important to have increased fitness and freedom but if done improperly, limited access to feed and aggression can be apparent. Electronic feeding systems (ESF) decrease aggression by sows having limited feeding competition, but young sows may still have to fight for access to the feeder and receive more injuries with lower production due to their lower ranking. Aggression may be decreased if sows are in groups of uniform parity. No difference was found on total number of piglets born alive in mixed or uniform groups. Parity 2 sows lost 4.12 mm of back fat in mixed groups and gained 0.22 mm in uniform groups. High parity sows were the only group to gain back fat in the mixed group as they were dominant in their access to the ESF system. Lameness was increased in mixed parity groups and lesions increased for all groups until 5 days post-mixing. Gilts, parity 1 and 2 sows may benefit from being managed separately.
Effect of Grouping Sows by Parity in ESF Housing on Welfare and Productivity (full article)
