Influence of diets containing different levels of Vicia faba L. as source of protein on body protein composition and nitrogen balance of growing rats.

Rats fed on Vicia faba as source of protein grew less than those fed a casein control diet. However, no differences were found on protein content of whole body, liver, muscle, and myofibrillar fraction. Nitrogen balance values were significantly higher in animals fed the casein diet than in those nourished with V. faba as source of protein. Minor differences due to the protein level of the diets were found. Retained nitrogen values were similar in all dietary groups. The inclusion of V. faba in the diet did not affect specifically muscle mass and protein distribution. It is suggested that differences reported in nitrogen balance are a consequence, at least in part, of the impairment of growth, although some other factors must be involved in this phenomenon.