Promoting sow-piglet information transfer and playful foraging by changes in pen design and feeding strategy to ease weaning: effects on pig performance and behaviour

Strategies inspired by the natural behaviour of pigs, including learning from the sow and playful foraging, may alleviate behavioural problems in weanling piglets and enhance their performance. We investigated the effects of a 'family feeding system' (Fs) and a dietary treatment providing 'family feeds' (Ff) in a 2 × 2 design on performance and behaviour until day 35 postweaning. Sows (n = 104) and piglets were either kept in the Fs or in a conventional system (Cs), and fed either the Ff or not (Cf). Fs sows could obtain feed throughout the day provided on a plate accessible to the piglets. Piglets and sows could also jointly drink and explore enrichment materials. The piglet feeder was identical in both systems, but in the Fs, it contained enrichment materials to stimulate playful foraging. Piglets were weaned at 27 days of age. Ff piglet feed, offered from postnatal day 2 until day 9 postweaning, contained the artificial flavour and several ingredients of the Ff sow's diet, allowing for flavour transfer, and had varying pellet size and length to increase texture diversity. Fs piglets were, apart from piglet feed, provided with sow feed for the first 4.5 postweaning days. Sow and piglet performance and body damage, number of eaters and postweaning behaviour and diarrhoea were determined. Less Fs than Cs sows had shoulder lesions. In the Fs, the proportion of eaters, preweaning piglet growth and weaning weight were higher. Until day 9 postweaning, Fs piglets' feed intake was higher, but growth lower, possibly due to a higher incidence of diarrhoea in this period. BW at day 35 postweaning was unaffected by system. Ear and tail damage and body lesion scores were decreased in Fs compared to Cs piglets pre- and postweaning, along with ear and tail biting behaviour postweaning. The Ff did not affect preweaning performance, but increased postweaning diarrhoea until day 9, proportion of piglets with damaged ears on day 9 and tail biting frequency, with no effect on postweaning growth. The postweaning intake of sows' feed in Fs piglets and the use of ingredients from the sows' diet in the Ff piglet diet might partly explain the high incidence of diarrhoea in these piglets, and thereby the absence of positive effects of the Fs and Ff on postweaning gain. In conclusion, strategies based on the natural behaviour of pigs seem promising to enhance piglet welfare around weaning, but further adjustment to their postweaning nutritional needs is required.