No. 7. DEPARTMENT OF AGRICULTURE. 203 



to infer, therefore, that the nitrogen is not deposited in the muscular 

 tissue and other organic matters in the body and kept there? 



DR. ARMSBY: My statement was in regard to mature animals, 

 that the amount given off was equivalent practically to that taken in. 

 That is not necessarily saying that it is not temporarily deposited, 

 but the balance is equal on the two sides, that is to say, the mature 

 animal has no considerable capacity for producing lean meat tissue. 



PROF. HAMILTON: If that is the fact, is it important, if you de- 

 sire an animal to give a large amount of lean meat, to select a breed 

 that has that characteristic? 



DR. ARMSBY: Yes, and you have to make your meat very largely 

 while the animal is growing. These experiments have shown that 

 the rate of lean meat production diminishes very rapidly, and the 

 tendenc}^, as the animal grows older, is towards fat production. 



MR. DRAKE: This first table, does that apply to all animals? 



DR. ARMSBY: No, that applies to the least amount of protein re- 

 quired by a thousand-pound cow giving 20 pounds of milk a day. 



MR. DRAKE: Does that apply to all animals? 



DR. ARMSBY: No, that is for cattle. It is about .6 per lb. for 

 a thousand-pound animal and approximated more or less in propor- 

 tion to the weight; it don't apply particularly to horses, sheep and 

 hogs. 



'a- 



MR. LIGHTY: Provided I would have a cow that would give a 

 proportionately large amount of normal milk, would the work of pro- 

 duction of that milk have anything to do with the best theory of 

 feeding; would there be a requirement for a larger maintenance 

 ration, or if my neighbor would feed a ration that would be very 

 difficult to digest and that animal would have to work very hard to 

 digest that, wouldn't that tear down some of the tissue so that the 

 maintenance ration would have to be larger? Is that possible, or 

 will that remain practically stationary? 



DR. ARMSBY: That is largely a question of the way of looking at 

 it. Undoubtedly that extra work would have to be supplied in some 

 way or other; that would come largely, however, from the non-nitro- 

 genous ingredients of the food or body. 



MR. LIGHTY: I ask whether the tissues would be broken down 

 by the work, or would they be replaced? 



