Conditioned flavour preference in pigs: comparison between caloric and/or gustative reinforcements

We induced a conditioned preference toward a flavoured beverage via caloric and/or gustative reinforcement. During 6 two-day conditioning sessions, 9 juvenile pigs received flavoured beverages added with sucrose (F+)or with no additive (F-). During conditioning, the pigs consumed F+ more than F-. F+ was also significantly preferred during a further two-choice drinking test without sucrose, suggesting that the pigs developed a short-term preference for a flavour previously paired with sucrose. To study the efficiency of visceral (calories) vs. gustative (sweet taste) reinforcements in preference conditioning, 9 pigs were subjected to 4 three-day conditioning sessions and received flavoured beverages added with maltodextrin (F+m, calories), saccharin (F+s, sweet taste), or no additive (F-). During conditioning, the pigs consumed F+s less than F+m and F-. During further two-choice tests, no clear-cut preference emerged, but the consumption of F+m was 107% higher than that of F-. These findings suggest that a visceral reinforcement might be sufficient to condition a flavor preference. Further studies are needed to investigate the failure of saccharin-conditioned preference