The Utilization of Food Elements by Growing Chicks. IV. Meat Meal and Fish Meal Compared with Meat Meal, Fish Meal, and Soybean Meal as Protein Concentrates

1. Two groups of 15 newly hatched chicks were fed rations differing in the composition of the protein concentrates. One lot received ration 2MFX, in which the concentrate was a mixture of meat meal and fish meal. In ration 3MFSX one-third of the meat and fish meals was replaced by soybean meal. The protein levels of the concentrates and of the rations as fed, were identical. 2. The composition of the chicks at the end of the feeding trial was determined, and the composition of the gains calculated. 3. The gain in live weight per gram of nitrogen or dry matter fed was practically identical in the two lots. 4. The retention of nitrogen by the chicks of the two lots was not significantly different. 5. The variation within lots was as great as that between lots; hence the slight variations in the retention of calcium and phosphorus were not judged significant