SUMMARY Two trials were conducted to study the extent to which the broilers are in need for animal protein. The effect of all plant protein diet (C/SBM) and meai (FM) sup < /strong>p < /strong>lemented-ones was tested in relation to the bird performannce. One day-old Arbor Acre broiler chicks were used in trial i to trace the effect of 10 treatments for 7 weeks feeding period. 7, 4 & 2% FM diets, C/SBM with extra vitamins (AD3E & B comp < /strong>lex) and corn/autoclaved SBM diets (C/SBM "A") were conducted in a trial and the level of 7% FM was tried to be fed for 1,2,3 & 4 weeks of age and compared with the same level along the whole fattening period in another trial. All FM diets were surpassing the C/SBM diets in stimulating the growth together with increasing the efficieency of feed conversion and the 4% level was the op < /strong>timal one. The C/SBM diets failed to satisfy the needs for growth and to protect the chicks against nutritional disorders, where leg disorder was appeared in the chicks. However, rapid growth was achieved if the supp < /strong>lementation with the FM was confined to the first 3 or 4 weeks of age. FM diets in spite of being costy, it is proved to be more economic.