An increase in growth rate from the addition of various animal protein factor (APF) supplements to all vegetable protein diets has been demonstrated by many workers. However, there are few published reports giving a direct comparison of the effects of such supplements when added to practical diets.Seven treatments are compared in the trials reported in this paper. Quadruplicate pens, 10 birds per pen, were used for each treatment, and the chicks and treatments were assigned to the pens at random. Female New Hampshire chicks obtained from a commercial hatchery were used.The composition of the basal diet per 100 lbs. was as follows: ground yellow corn 27.5, ground oats 12.5, rolled oat groats 7.0, ground barley 6.0, dehydrated alfalfa meal 3.0, ground wheat 15.0, soybean oil meal (solvent) 26.0, steamed bone meal 1.0, fortified fish oil (2400 A-400 D) 0.24, salt (iodized) 0.6, ground limestone 1.0, MnSO4.4H2O 9.00 gm., .