Effects of reward type and previous social experience on cognitive testing outcomes of weaned dairy calves

Animal cognitive and behavioral testing often requires a reward to motivate task acquisition, yet reward perception may depend on reward type and previous experience. We first assessed the effects of reward types on initial discrimination and reversal learning ability in weaned dairy calves, with calves tested in a T-maze containing either a food, social, or exit reward. During the initial stage, success rate was greater for calves provided the social vs. food reward, whereas success in the reversal stage was greater for calves provided the exit vs. social reward. We also assessed effects of social experience in calves previously housed individually or in pairs tested with either a social or exit reward. Interactive effects of previous housing and reward type were evident during the initial discrimination stage of testing, with previously pair housed calves relatively more successful if given the exit reward and individually housed calves relatively more successful if given the social reward. During the reversal stage, success rate was greater for calves given the exit reward, particularly if previously housed individually. These results suggest that previous social experience can affect the subjective perception of different reward types, and that the subjective valuation of an exit reward may uniquely increase with repeated testing.