398 Journal of Agricultural Research voi. xviii. No. 7 



urea, and amino acids) regardless of the total weight of nitrogen in the 



sample, and that only the uric acid, etc., increased in amount as more 



protein was fed. 



SUMMARY 



In conclusion, it would seem that it is possible to secure nearly normal 

 growth of chicks when raising them in conhnement, and that this method 

 has many points of advantage as a means of measuring the biological 

 value of feeds for chickens. 



These results indicate that there is a wide range in the amount of pro- 

 tein which may be fed with little difference in results except in economy 

 in feed consumption. 



When the basal ration was supplemented with varying amounts of 

 protein from meat scraps, soybean meal, or combination of the two. it is 

 shown that an addition of 10 parts of protein from soybean meal gave 

 the best growth. The next best gains came from lo, 15, and 20 parts of 

 protein from the combination of soybean meal and meat scraps. All 

 the meat scraps rations were found to be somewhat inferior to those of 

 the soybean meal or the combination. 



The amount of nitrogen present in the feces as ammonia, urea, or 

 amino acids (soluble in N/io hydrochloric acid) was nearly constant 

 regardless of the total nitrogen present in any sample, the remainder 

 of the nitrogen present being due largely to the uric acid. The amount 

 of excreted nitrogen was dependent on the amount of the protein con- 

 sumed and increased proportionately. 



The data which have been presented tend to show that chicks are 

 capable of greater utilization of soybean meal protein than are mammals, 

 with which nearly all previous nutritional work has been done. 



