Principles for the Use of Non-protein-nitrogen and 'bypass' Proteins in Diets of Ruminants

The apparent inefficiency of ruminants compared with monogastric animals in utilising protein rich feeds has been used as an argument to emphasise the importance of monogastric animals in preference to ruminants for meat production. Recent studies however (see Preston & Willis, 1970 ; flrskov, Fraser, McDonald & Smart, 1974 ; Kempton & Leng, J-976 ), have indicated that with correct balancing of digestible nutrients, ruminants given feed of apparently variable quality can grow at rates much greater than those generally reported ($rskov, 1976). These results have been achieved with approximately 50 70% of the usual recommended requirements for protein in a diet. Ruminants are therefore potentially highly efficient users of protein feeds under a variety of agricultural situations, including the utilization of low protein by-products of agro-industries.