200 ANNUAL REPORT. OF THE Off, Doc. 



one lot as in the other. If we had run only the one lot and compared 

 them in the ordinarj' way,, we should have concluded that the protein 

 did make some dillerence in the yield of milk in the middle periods 

 where we cut off some of the protein, we didn't get as much milk but 

 we found that whatever was the cause of that, it was not the dimin- 

 ishing of the protein. 



In this experiment there appears a little greater falling off than 

 there should be in that middle period. It was a very wide, nutritive 

 ration and very low protein-content. On the whole, I think, the clear 

 teaching of these results is, as I indicated in the beginning, that per- 

 haps we have overestimated the importance and overstated the 

 amount of protein necessary for the dairy cow; I say perhaps. In 

 one point of view, I ought to give you something that is certain. I 

 feel, however, that one of the important functions of a gathering 

 like this is to get these gentlemen who are to act as instructors to 

 thinking on some of these problems. I do not conceive it to be the 

 function of this Normal Institute to simply fill you up full of some- 

 thing that you are going to pour out later. The function of the in- 

 stitute worker is essentially that of a translator, to see how these 

 principles have been worked out and applied, not to act simply as a 

 vehicle of transmission, but to think on these questions, and to work 

 out his own conclusions and his own best judgment to his audiences, 

 and so it is not felt that it was out of place to bring forward a ques- 

 tion which cannot be answered perhaps categorically and absolutely. 

 I think we are safe in saying, however, that a dairy cow does not 

 need very much more protein than is equivalent first, to what she re- 

 quires for maintenance^ and second, to what she will normally put 

 into her milk. Any good dairyman knows how much he can expect 

 from a cow — how much protein he expects that dairy cow to give 

 I'.im in the milk-pail. He can add to that the protein required for 

 maintenance, and I think he won't need to go very much beyond that 

 to get a sulfident ration so far as protein is concerned. 



As I suggested, this matter has been discussed a great deal from 

 the standpoint of nutritive ratio, so-called. It is not a question 

 primarily of ratio; it is a question of amount. Suppose I feed my 

 cow — my herd — with a moderately Vv^ide ration. If I make up that 

 ration of foods that are not very palatable, the cow does not quite 

 like them, and so feeds rather lightly, or I don't give her quite 

 enough, she may fall short on protein. But if I take another ration 

 just like that in nutritive ratio, but on which the cow feeds liberally, 

 she may get enough protein, all she needs out of a ration of exactly 

 the same nutritive ratio; you avoid that ambiguity if you consider 

 how many pounds of nutritive protein you have got to supply and 

 I can't see that it is going to aid much if I neglect that ration by put- 

 ting extra carbohydrates in that ration. I think, in general, we have 



