Nutrition

Abstract

Mammals have developed a wide spectrum of nutritional as well as ecophysiological adaptations to very diverse habitats and a range of different types of food. In herbivorous mammals, two major sites of digestion and fermentation of the ingested food have become clearly differentiated. These sites are the forestomach and the hindgut. Forestomach fermenters are essentially adapted to low-quality food. This is because it is of advantage to break low-quality food down into its digestible components as early in the process as possible. Hindgut fermenters adapted to a high-quality diet have less need for such an early breakdown of food. Forestomach fermenters can therefore be considered to be more likely to be found in open biomes (Langer 1984). Desert ruminants are forestomach fermenters adapted to poor-quality food in open biomes. They are also usually adapted to periodic nutritional stress which they combat through a series of different strategies, including deposition of fat, reduction of metabolic rate and, in extreme cases, migration. Non-ruminant herbivores and non-herbivorous animals have adopted these and other strategies.