Meagher, R. K., Weary, D. M., von Keyserlingk, M. A. G. 2017. Some like it varied: Individual differences in preference for feed variety in dairy heifers. Applied Animal Behaviour Science 195, 8-14.
Motivation to explore is believed to be widespread among animals, but exploratory behaviour varies within populations. Offering variety in feed is one simple way of allowing intensively housed dairy cattle to express exploratory foraging behaviour...