If you give the pig a choice: suckling piglets eat more from a diverse diet

Stimulating solid feed intake in suckling pigs is important to ensure a successful weaning transition, exemplified by the correlation between pre- and post-weaning feed intake. In nature, piglets begin to sample food items in a playful manner when only a few days old. In pig husbandry, contrarily, suckling pigs are not encouraged to forage, whereas we hypothesize that this is crucial to increase piglet robustness via improved intestinal and gut microbiota development. One approach to familiarize pigs with solid feed at an early age ight be by providing feed in a variety of forms, using diversity or novelty to stimulate the pigs’ foraging behaviour. We studied the effect of dietary diversity (i.e. offering two diverse feeds simultaneously) vs novelty (i.e. regularly hanging the flavour of one feed) on the foraging behaviour and feed intake of suckling pigs. We also hypothesized that piglets, rather than sampling from one feed only, would prefer a diverse diet. Piglets received ad libitum feed from 2 days of age in two feeders per pen. In treatment 1 (T1, n=10 pens) pigs were given feed A and feed B which differed in size, flavour, composition, smell, texture and colour. In treatment 2 (T2, n=9) pigs received feed A plus feed A to which additional novel flavours (4 different ones) 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; d10, 15, 22; n=6 pens per treatment). Observations were also used to determine ‘eaters’ (i.e. pigs scored eating at least once). Data were analyzed using mixed models. Piglets did not prefer feed A(d2-22: 196±16 g/pig) or B (152±13) within T1 and did not have an overall preference for feed A with (d6-22: 78±4 g/pig) or without flavour novelty (66±6) within T2. In accordance, just a few piglets (T1: 1.5% and T2: 3.2% out of all eaters per treatment) were observed eating only one of the feeds throughout lactation. Interestingly, T1-pigs (d2-22: 327±28 g/pig) ate muchmore than T2-pigs (147±9; P<0.0001) and explored the (feed in the) feeders 2.6 times more at d15 (P=0.001). This also implies that feed A, the common feed provided in T1 and T2, was more consumed in T1 (d6-22: 152±13) compared to T2 (68±5; P<0.0001). The percentage of eaters within a litter did not differ over time between T1 (d10: 26%, d15: 78%, d22: 94%) andT2 (20, 71 and 97%). In conclusion, our results suggest that piglets like to eat a varied diet instead of preferring one feed over the other. Dietary diversity by providing two feeds at the same time different in flavour, size, composition, smell, texture and colour stimulated the feed intake and feed-related exploratory behaviour of suckling pigs more than dietary diversity via novel flavours only, but did not elicit pigs to start eating earlier. Further research is needed to explore the most effective dietary diversity to stimulate early feeding.