Efficiency of Digestion in Goats and Sheep

摘要

The process of converting plant fiber to animal product is complex. Simplistic measures of efficiency such as average product per unit of feed input can be misleading if they do not reflect the critical biological and economics points in this process. Efficiency of protein utilization in the ruminant is influenced by dietary concentrations of non-protein nitrogen, true protein, and bound (unavailable) nitrogenous substances. Energy is derived from rapidly soluable carbohydrates and slowly degradable cell-wall cellulose and hemicelluloses. Intake of energy is influenced by the presence of non-degradable cell-wall matter and its rate of passage through the digestive tract. There is evidence that the goat, compared with sheep and cattle, has become adapted to a low-quality feed resource through his ability to selectively consume the more nutritious (less fibrous) plant parts, and to pass his digesta through at a faster rate.