Pig Responses to Taste Stimuli

Abstract

Since 1966, researchers have tested various primate species in experiments investigating their behavioral response to gustatory stimuli. We found a great diversity within the order of primates in their response to compounds sweet in man. Our studies focus on pigs, (Sus scrofa domesticus). Pigs are omnivores like humans, and their physiology shares many common points with humans. Expect for limited behavioral and electrophysiological studies in which pigs were exposed to familiar gustatory stimuli (sucrose, glucose, etc.), relatively few reports have described responses to wide diversity of gustatory stimuli (see Glaser et al., 2000). The members of Suidae in order Artiodactyla, are known from the Lower Eocene (≈ 55 MYA); although they probably emerged during the late cretaceous time. Several families of primitive pig-like forms are known in the Eocene, and therefore, they are more ancient than the catarrhine primates (of ≈ 37 MYA; Carroll, 1988). Importance of taste is indisputable in many aspects of behavior, particularly for the selection of food, which is essentially based on palatability. Therefore, in previous work, we determined the gustatory responses of pigs to various natural and artificial compounds known to be sweet in humans (Glaser, et al., 2000). The purpose of the present work is to extend this knowledge of the pig taste by experimenting compounds representative of different taste qualities (salt, bitter and acid tastes) in addition to alphaamino acids, many of which are known to be sweet in humans.