We aimed to study the effects of pre- and postnatal flavour exposure through the maternal diet on performance and behaviour of newly weaned piglets offered a similarly flavoured food.
Sows (n=18) were offered anise-flavoured (F) or control (C) food during late gestation for 10 days. Piglets were cross-fostered after birth, with each sow fostering five piglets from an F sow and five from a C sow. During lactation, sows were offered F or C feed, resulting in FF, CF, FC and CC piglets (n=9 groups of each treatment). Piglets were weaned, relocated and mixed with unfamiliar same-treatment pigs (4 per pen, 2 of each sex) on day 25 and were given both control and anise-flavoured food for two weeks in a choice food approach. Pen averages for body weight, feed intake, diarrhea and behaviour were analyzed using a mixed model (repeated measures when appropriate) including pre- and postnatal exposure, their interaction and batch (two) as factors. No clear effect of exposure on anise preference was found. Prenatally exposed animals (FF+FC piglets) showed a higher food intake on day 2, 3 and 5 (on average 0.30±0.03 vs. 0.27±0.04 kg/pig/day, p<0.10), a higher bodyweight during the postweaning period (on average 10.5±0.12 vs. 10.2±0.26 kg, p=0.07) and lower diarrhoea occurrence (1.9±0.25 vs. 2.8±0.41) days, p=0.04) compared to prenatally non-exposed animals (CF+CC). Prenatal exposure (FF+FC) also increased the latency to fight (29.9±4.6 vs. 19.7±2.1 minutes, p=0.02) and decreased mounting behaviour (0.65±0.13 vs. 0.83±0.15% of time, p=0.03). Pre- and postnatal exposure (FF treatment) reduced oral manipulation of pen mates (0.68±0.14 vs. 1.49±0.17% of time, p=0.06). These findings suggest that a familiar flavour from the sow's gestational diet in the postweaning diet reduces stress and possibly food neophobia, resulting in a higher performance and welfare of piglets after weaning.