370 



EXPERIMENT STATION EECOED. 



Experiments in milk production were made witli milcli goats and slieep. In 

 one test ammonium acetate was used as a supplement to tlie normal ration, 

 and in another test it was used as a substitute for the pure protein part of the 

 ration. In other tests amid extracts were used, the ration always containing 

 the same amount of pure protein as the basal ration, but the amount of crude 

 protein varying according to the nature of the source of the extract. The 

 average milk production when a change was made from the normal ration is 

 given in the following table : 



Average yields of milk and milk solids and percentage of milk fat with different 

 rations as compared with yields on a normal ration. 



Ration. 



Ammonium acetate as a supplement 

 Ammonium acetate as a substitute. . 



Amid extract of grass 



Amid extract of beet chips 



Amid extract of malt sprouts 



Yield of 

 milk. 



Per cent. 

 97.3 



92.6 

 89.9 

 96.4 



Yield of 



dry 

 matter. 



Per cent. 

 96.0 

 67.8 

 91.8 

 87.3 

 92.8 



Yield of 

 nitrogen. 



Per cent. 

 95.2 

 67.6 

 87.0 

 83.7 

 88.7 



Yield of 



fat. 



Per cent. 

 97.1 

 67.2 

 102.2 



89.7 



Relative 

 percent- 

 age of fat. 



Per cent. 

 99.4 

 97.8 

 113.0 

 100.4 

 102.1 



The highest yield of milk and its constituents was obtained from the basal 

 ration except in a few cases, where the sub.stitute ration gave slightly higher 

 percentages of fat. The addition of ammonium acetate to the basal ration did 

 not materially decrease the yield, but when the protein of the basal ration was 

 largely replaced by ammonium acetate the yield was decreased as in former 

 experiments. The form of carbohydrate did not affect the values- of ammonium 

 acetate. There was no appreciable effect on the live weight of the animals. 

 The introduction of amid extracts decreased the yield slightly but somewhat 

 less than in previous years. Ammonium acetate as a supplement was without 

 effect upon the valuation of nitrogen metabolism, as in the case of substitution. 

 During the amid extract period there was a larger amount of protein in the 

 feces than in the normal ration. A substitution of ammonium acetate caused 

 no increase of protein in the feces ; hence, the formation of so-called indigest- 

 ible bacterial protein out of ammonium acetate, as formerly suggested, was not 

 substantiated. The average coefficients of digestibility of rations are given 

 in the following table : 



Average coefficients of digestibility of rations. 



Basal ration 



Ammonium acetate supplement. . . 

 Ammonium acetate as a substitute 



Amid extract of grass 



Amid extract of beet chips 



Dry 



matter. 



Per cent. 

 69.0 

 69.9 

 66.7 

 66.4 

 66.5 



Crude Pure 



protein, protein. 



Per cent. 

 85.7 

 90.5 

 85.4 

 80.8 

 82.3 



Per cent. 

 85.1 

 85.0 

 67.0 

 78.4 

 81.3 



Fat. 



Per cent. 

 77.1 

 72.4 

 76.9 

 81.1 

 73.0 



Nitrogen- 

 free 

 extract. 



Per cent. 

 80.5 

 79.7 

 77.3 



75.4 



77.7 



Fiber. 



Percent. 

 48.0 

 46.2 

 44.5 

 51.9 

 47.9 



In metabolism experiments with wethers on similar rations the nitrogen bal- 

 ance showed a daily loss of 3 gm. of niti'ogen during the period of feeding straw 

 and ammonium acetate. On adding a small amount of distillery slop this was 

 reduced to 1.78 gm., and to 0.29 gm. by adding a large amount of slop. The 

 favorable effect of the slop showed that the straw was poorly digested without 

 it. The depression was due to a lack of protein in the straw. The excess of 

 nitrogen in the feces was due to products of metabolism and not to bacteria. 



