Use of Unpalatable Forages by Ruminants: The Influence of Experience with the Biophysical and Social Environment

Unpalatable forages, due to either low nutrient content or the presence of toxic compounds, are widespread and represent a challenge for ruminant nutrition, health, and welfare. If we find ways to encourage consumption of unpalatable forages, they could provide at least part of the nutrient requirements of ruminants. Our objective was to synthesize the role of diverse environmental experiences on the use of unpalatable forages by ruminants. Experimental evidence shows that experience can alter both morpho-physiological and psychological (learning) mechanisms to better cope with unpalatable forages, particularly early in life when body functions are more amenable to change. Furthermore, experiential learning provides flexibility in diet selection, which is critical in changing foraging environments. By understanding and applying behavioural principles, it is possible to better devise management plans that optimize the nutrition, health, and welfare of herbivores grazing unpalatable forages throughout their life. In addition, a more uniform use of resources can be achieved from the landscape level down to the individual plant, with consequent benefits to ecosystem integrity and stability