Interpretation and Significance of Nutrient Balance Experiments

Nutrient balance studies have been used extensively in nutritional research. Several problems of determination have been observed. These include errors in collection and sampling of feed and excreta, loss vectors not measured, correspondence of excreta collections and feed intake. Such errors usually result in overestimations of actual balance and render absolute values questionable. In addition, experimental design may influence results. Balance data are influenced by levels of other nutrients, growth rate, depletion status of the animals, adaptation periods, and other factors. Suggested guidelines for planning and interpretation of balance trials are presented.