Proceedings of the Nutrition Society

Cambridge Journals Online - CUP Full-Text Page

Symposium on ‘Social and environmental influences on diet choice’

Conditioned food aversions: principles and practices, with special reference to social facilitation

Michael H. Ralphsa1 c1 and Frederick D. Provenzaa2

a1 USDA/ARS Poisonous Plant Laboratory, Logan, Utah 84341, USA

a2 Rangeland Resources Department, Utah State University, Logan, Utah 84322, USA

Article author query

Ralphs MH [PubMed]  [Google Scholar]
Provenza FD [PubMed]  [Google Scholar]


Conditioned food aversion is a powerful experimental tool to modify animal diets. We have also investigated it as a potential management tool to prevent livestock from grazing poisonous plants such as tall larkspur (Delphinium barbeyi), white locoweed (Oxytropis sericea) and ponderosa pine (Pinus ponderosa) on western US rangelands. The following principles pertain to increasing the strength and longevity of aversions: mature animals retain aversions better than young animals; novelty of the plant is important, although aversions can be created to familiar plants; LiCl is the most effective emetic, and the optimum dose for cattle is 200 mg/kg body weight; averted animals should be grazed separately from non-averted animals to avoid the influence of social facilitation which can rapidly extinguish aversions. Social facilitation is the most important factor preventing widespread application of aversive conditioning. When averted animals see other animals eat the target food they will sample it, and if there is no adverse reaction they will continue eating and extinguish the aversion. However, if averted animals can be grazed separately, aversions will persist. Aversive conditioning may provide an effective management tool to prevent animals from eating palatable poisonous plants that cause major economic loss.

Key Words: Diet selection; Conditioned food aversion; Social facilitation; Poisonous plants


c1 *Corresponding Author: Dr Michael H. Ralphs, fax +1 435 753 5681, email