Prenatal flavour exposure through maternal diets influences flavour preference in piglets before and after weaning

Abstract

Flavour cues present in amniotic fluid are used in mammals to find their mother early, but they are also useful for having contact with environmental flavours before birth. Three experiments have been performed to evaluate if piglets, during lactation and post-weaning, have the ability to prefer natural or artificial cues previously added to the gestating diets. For 7 min, pigs, in pairs, were offered a triple-choice stimulus through a Triple-U-Testing Arena among maternal amniotic fluid, alien amniotic fluid or water (Experiment 1) or among a flavour added to the late-gestation diet, a control flavour and water (Experiment 2). The same prenatal strategy was used to study the piglet's preference for flavoured or unflavoured creep feed during the suckling period (Experiment 3). Suckling piglets preferred amniotic-fluid flavours from their own mother over an alien amniotic fluid and they also preferred specific flavour cues given to the sows during late gestation (anise and milky-cheese). However, prenatal flavour exposure did not improve the preference of piglets for a flavoured compared to an unflavoured creep feed diet. Pre-natal exposure to flavours via maternal diet influences the piglet's preferences for new flavours, probably through a positive association between flavours and the hedonic reward of the uterine experience and a familiarity effect. Nevertheless, our results do not exclude alternative routes of exposure of the newborn piglets to sow feed odours. Preferences acquired before birth seem to be long-lasting. This may be an important factor to reduce neophobia for specific flavours in young pigs.