MANUAL or CATTLE-JFEEDIITG. 193 



of fat in the food canses an increased deposition of fat in 

 the body, an increase of the carbhydrates does this only 

 up to a certain Ihnit. For example, if fat be fed to a fast- 

 ing animal in more than sufficient quantity to supply the 

 necessary consumption, the excess is deposited in the body, 

 and the moi^e fat is fed the more is thus deposited. If 

 carbhydrates be fed in this way, they are oxidized in the 

 blood, and a corresponding quantity of the body-fat and of 

 that produced fi-om the decomposition of the albuminoids 

 of the body is piotected from destruction. If enough 

 caibhydiates are fed, all the fat separated fi'om the pio- 

 tein may be deposited as body-fat. Thus far the action is 

 essentially like that of fat, but 'if we morease the carlhy- 

 dmtes heyond this^oint we get no further laying on of fat. 

 The quantity of fat deposited in the body under such cir- 

 cumstances is found to be proportional to the amount of 

 the protein consumption, and the excess of carbhydiates is 

 simply burned up, producing an increased excretion of car- 

 bonic aeid."^ Essentially the same results were obtained 

 when carbhydrates weie fed along with albuminoids. In 

 no case was the gain of fat greater than coi responded to 

 the ready-formed fat of the food and that which could be 

 produced from the albuminoids, and any excess of carbhy- 

 drates over that required to protect this amount of fat from 

 oxidation produced no effect except an iilcreased excretion 

 of carbonic acid. 



On the other hand, it has been observed that when a 

 larfi^e quantity of carbhydrates are fed, and the albumi- 

 noids are gradually increased, the gain of fat also in- 

 creases. 



The following expeiiments illustrate this: 



See foot note, p 184 



