46 Feeds and Feeding. 



64. Nitrogenous waste in the urine. — During the day the ox gave 

 off 30.6 lbs. of urine which contained 170 grams of nitrogen. We 

 can determine the amount of nitrogenous substance which was 

 broken down to produce this waste in the following manner : 

 About 16 per ct. of such nitrogenous substance as was in the food 

 of the ox or composed its body tissues was nitrogen. Multiplying 

 170 grams by 100/16, or 6.25, gives 1,062 grams, or 2.33 lbs., which 

 represents the amount of nitrogenous substance that was broken 

 down and passed away in the urine. This nitrogenous waste came 

 either from the food which the ox had consumed during the day, 

 or resulted from the breaking down of the lean-meat tissues of the 

 body which lost the condition of life and passed away as dead 

 matter. 



65. Dry lean meat. — Division C of the table shows that during 

 the day of the study the body weight of the ox was increased by 

 1,035 grams as follows : 



Grams Pounds 



Total substance passed into the body 78,130 171.8 



Total waste leaving the body 77,095 1G9..5 



Amount remaining in the body for the day 1,035 2.3 



Let us now direct our attention to the 2.3 lbs. of income which 

 really became a part of the body. We learn from the table that 

 during the day of this study the ox stored up 35 grams of nitrogen 

 in its body. Sixteen per ct. of the nitrogenous substance or pro- 

 teins of the body, such as dry lean meat, is nitrogen. Accordingly 

 the 35 grams of nitrogen retained in the body represents about 219 

 grams of dry lean meat. The table shows that 330 grams of carbon 

 were retained by the ox. As dry lean meat is a little over half 

 carbon, about 115 grams of carbon were built into the 219 grams 

 of dry lean-meat proteins. 



66. Dry fat. — Since the lean meat took up 115 grams of carbon 

 there remains 215 grams of carbon out of the total of 330 grams. 

 This must have gone into the fatty matter stored during the day. 

 Pure fat is about three-fourths carbon, llence the 215 grams of 

 carbon represents about 281 grams of dry body fat. From this we 

 learn that about 281 grams of dry fat were stored in the body 

 during the day of trial. 



67. Summary. — From all this we learn that during the 24 hours 

 spent by the ox in the respiration chamber, out of a total intake 



