Dietary diversity affects feeding behaviour of suckling piglets

Stimulating solid feed intake in suckling piglets is important to facilitate the weaning transition, exemplified by the positive correlation between pre- and post-weaning feed intake. The present study compared the effect of dietary diversity (i.e. offering two feeds simultaneously) and flavour novelty (i.e. regularly changing the flavour of one feed) on the feeding behaviour and performance of suckling piglets until weaning at day 22. It was hypothesized that presentation of the feed in a more diverse form, by varying multiple sensory properties of the feed, stimulates pre-weaning feed intake. Piglets received ad libitum feed from 2 days of age in two feeders per pen (choice feeding set-up). One group of piglets (dietary diversity (DD), n = 10 litters) were given feed A and feed B which differed in production method, size, flavour, ingredient composition and nutrient profile, smell, texture and colour. The other group of piglets (flavour novelty (FN), n = 9 litters) received feed A plus feed A to which one of 4 flavours were added from day 6 in a daily sequential order. Feeding behaviour was studied by weighing feed remains (d6, 12, 16, 22) and by live observations (4-min scan sampling, 6 h/d; d9, 14, 21; n = 6 litters per treatment). Observations were also used to discriminate 'eaters' from 'non-eaters'. All piglets were weighed at d2, 6 and 22. Piglets did not prefer feed A (d2-22: 1.4 +/- 0.16 kg/litter) over B (1.6 +/- 0.18) within DD nor had a preference for feed A with (d6-22: 1.1 +/- 0.06 kg/litter) or without additional flavours (0.9 +/- 0.07) within FN. Nevertheless, DD-litters (d2-22: 3.0 +/- 0.32 kg) ate significantly more than FN-litters (2.0 +/- 0.12 kg; P = 0.02) and explored the feed 2.6 times more at d14 (P = 0.001). Furthermore feed A, the common feed provided in DD and FN, was more consumed in DD (d2-22: 1.4 +/- 0.16 kg) compared to FN (1.0 +/- 0.07 kg; P = 0.04). The percentage of eaters within a litter did not differ over time between DD (d9: 26%, d14: 78%, d21: 94%) and FN (20%, 71% and 97%) and no effect was found on pre-weaning weight gain. In conclusion, this study showed that provision of dietary diversity to suckling piglets stimulated their feed exploration and intake more than dietary flavour novelty only, but did not enhance the percentage of piglets within a litter that consume the feed or their growth performance. These data suggest that dietary diversity could be an innovative feeding strategy to stimulate solid feed intake in suckling piglets.