Feeding behavior of grazing ruminants experiencing stress.

摘要: The mechanisms underlying diet selection of ruminants are less studied than those for monogastrics. However, recent studies have shown that these may be more similar in and monogastrics previously believed. Food aversion learning is observed both ruminants, the hypothalamic-pituitary-adrenal axis appears to involved avoidance learning. Using leafy spurge (Euphorbia esula), an introduced weed whose expansion has costly ecological economic implications western North America, as a model underconsumed plant species, we hypothesized sheep experience increased cortisol levels when they first consume this related their reluctance graze it. We also preexposure would attenuate development spurge-based aversion. Correspondingly, preexposed not blood with gavage during trial. None our hypotheses were disproved by experiments. Our results lend support hypothesis stress required conditioned taste aversions extend it ruminants. suggest activity integral food