MANUAL OF CAlTrLE-FEEBIKG. 113 



Tlie ealciilatioii of tlie gain or loss of flesh hs^ alreaily 

 been explained. Bj detenniiiing the aoiount of carbon 

 coiitaiaed in the carbonic acid excreted through the lungs 

 and skin and in the urea, etc., excreted bj the kidtieys, 

 and comparing it with the amount contained in the di- 

 gested portion of the food, we can find wdietlier the ani- 

 mal is gaining or losinsf carbon in the same manner as we 

 can determine whether it is gaining or losiiig nitrogen. 

 If the excreted carbon is less than that contained in the 

 food, the difference must have been retained in the IkkIv ; 

 if greater, the excess nuist have come from the tibsueb of 

 the body. The gain or loss of carbon, however, may have 

 been in one or both of two fonns ; viz., fat or albnminoids. 



If the comparison of the nitrogen in ftnider and excre- 

 ments shows that the body has neither gained nor lost albu- 

 minoids^ then the carbon gaine<i or lost was all in the form 

 of fat, since the other non-nitrogenous substances in the 

 body are so small in amount that they can lye nciyleeted. 

 Ikit every 100 parts of fat contains, on an average (]>. 12), 

 Tt>.5 parts of carbon, and therefore every Tt>.5 parts of 

 carbon shown by the evperiment to have been gained ov 

 lost represents li^O parts of fat, or one part of carbon ci»r- 

 responds to 1.3 parts of fat. The method of calculation is 

 exactly similar to that used in calculating the gain or loss 

 of albuminoids from that of nitrogen. 



The calculation is essentially the same if a gain or loss 

 of albuminoids has taken place, except that the amount of 

 carbon contained in the latter must be deducted from or 

 added to, as the case may be, that found by experiment 

 before multiplying by the factor 1.3. An example will 

 render this clearer. 



In an experiinent made at the Weende Experiment Sta- 

 tion on sheep, the animals received per day and head Ij^iO 



