Diet selection of ruminants as a useful management tool in rangelands

Ruminants foraging on rangelands select their diets from an array of plants that vary in nutrients and toxins. Their senses of taste, smell, and sight help them to select an appropriate diet, which meets nutritional needs. Postingestive feedback adjusts a forage’ s value commensurate with its utility to the animal enabling survival when the grazing environment and animal’s nutritional needs are changing. Animals acquire preference for plant species that cause positive postingestive feedback (these species are usually correlated with adequate nutritional constituents); on the contrary they acquire aversion for plant species that cause negative postingestive feedback (these species are correlated with nutrient deficiencies or excesses and toxicities). In other words, what makes a forage preferable or not is not its taste but its nutritional benefits or deficits received from forage ingestion, which are sensed by animals through feedback and linked with a forage’s taste. The senses of smell and sight help animals to seek foods that cause positive feedback and avoid foods that cause negative feedback. Finally, in this article the implications of diet selection for rangeland management are discussed.