1913.] rUBLIC DOCUMENT — No. 31. 153 



between the iiifliieiice of the two rations has already been ex- 

 phiined. In this experiment hay was figured at $10, eorn meal 

 at $32, oats at $37.50 and bran at $20 a ton. 



CONCI.USIOIS^S. 



1. Chemical analysis and digestion tests indicate that oats 

 have about one-fourth less actual nutritive value than corn (on 

 basis of equal parts of dry matter), 



2. The three comparative experiments conducted Avith dairy 

 cows indicated that the oat ration produced practically as much 

 milk and butter as did the corn ration, but at 31/) per cent, 

 greater cost. 



3. The reason why the difference in the nutritive effect of the 

 two grains was not more sharply brought out probably lies in 

 the fact that the experiments themselves were not correctly 

 planned. The nutritive material in the total oat ration was 

 sufficient to enable the cows to do good if not maximum work, 

 and the increased nutritive material in the corn ration was not 

 necessary and had, therefore, no pronounced effect. The basal 

 ration (i.e., without the corn or oats) should have been less in 

 amount and then the results obtained from the addition of corn 

 and oats would have been more pronounced. 



4. Many experiments to compare the practical feeding values 

 of different feedstuff's do not return the results desired, for the 

 reason that they are not planned in a way to eliminate all but 

 the one point to be demonstrated. In fact, it is not believed that 

 experiments of this character can tell as true a story as investi- 

 gations resulting from analysis, digestibility and respiration 

 experiments, when the net energy values of the several feed- 

 stuffs can be fairly accurately ascertained. Experiments how- 

 ever, of the sort here described are useful in giving one a general 

 idea of the relative merits of different feeding stuffs, but care 

 should be taken to keep the basal ration considerably below the 

 amount of food needed, so that when the feeds to be studied are 

 added the total ration will still be a little below the amount 

 required by the animal for an average production. 



5. While oats are a valuable food, it is not believed they can 

 usually be fed economically to dairy animals in Massachusetts. 



