RESUMO
Use of visual cues to locate specific food resources from a distance is a critical ability of animals foraging in a spatially heterogeneous environment. However, relatively little is known about how long animals can retain the learned cue-reward association without reinforcement. We compared feeding behavior of experienced and naive Japanese Black cows (Bos taurus) in discovering food locations in a pasture. Experienced animals had been trained to respond to a visual cue (plastic washtub) for a preferred food (grain-based concentrate) 1 year prior to the experiment, while naive animals had no exposure to the cue. Cows were tested individually in a test arena including tubs filled with the concentrate on three successive days (Days 1-3). Experienced cows located the first tub more quickly and visited more tubs than naive cows on Day 1 (usually P < 0.05), but these differences disappeared on Days 2 and 3. The performance of experienced cows tended to increase from Day 1 to Day 2 and level off thereafter. Our results suggest that Japanese Black cows can associate a visual cue with a food reward within a day and retain the association for 1 year despite a slight decay.
