2 50 



Journal of Agricultural Research voi. xviii, No. s 



form. Apparently, however, there is but little relation between the 

 curves showing the live weights and the curves showing the protein and 

 energy consumption. 



As with the maintenance lot, the curves showing the nitrogen con- 

 sumption, the nitrogen excretion, and the urinary nitrogen are more or 

 less parallel from week to week. Though in general the curves showing 

 the nitrogen balance tend to follow the nitrogen consumption, yet there 

 are many instances where they do not. As might be expected, the stor- 

 age of nitrogen was greater in the one-third feed lot than in the main- 

 tenance lot. It also may be noted that in the one-third feed lot the 

 storage of nitrogen was more irregular than in the maintenance lot. 



/Sv-<3V V e a yo 1^ 7^ Tff i^ zB ee «^ 'se s^ 35 Ji? J^ JV j^ «o 

 Fig. 3. — Nitrogen metabolism of steers in the two-thirds feed lot. 



Two-thirds pe;e;d lot. — Figure 3 gives the data for the steers of the 

 two-thirds feed lot. It is seen that the consumption of protein and 

 energy was still further increased, resulting in greater gains as shown by 

 the more rapid incline of the live-weight curve. 



The curves showing the total nitrogen excretion and the urinary 

 nitrogen again follow the curve of the nitrogen consumption quite 

 closely. The storage of nitrogen again follows the nitrogen consumption 

 more or less closely with numerous irregularities. In general the curve 

 is higher than in either of the lots previously studied. 



FuivL FEED LOT. — Figure 4 gives the corresponding curves for the full 

 feed lot. It is noted that the consumption of protein and energy was 

 somewhat greater than in the preceding lot, resulting in still better gains 



