摘要: Publisher Summary Dietary proteins, through digestion in the gastrointestinal tract, furnish amino acids and polypeptides, which are raw materials needed to build body proteins of animals. These essentially form matrix living system; centers around dynamic equilibria life develop. This chapter focuses on biological evaluation these proteins. The value a protein refers amount nitrogen retained an animal. A new phase research nutritive includes mixtures replacing pattern essential varies with physiological state animal species. retention is function this pattern. simplest method used evaluate determine difference between intake excreted. difference, called balance, shows whether maintaining, losing, or gaining nitrogen. Correlations acid composition can be excellent, when represents acids, absorbed into Along growth tissue regeneration also presented.