90 



MAINTENANCE RATIONS OF FARM ANIMALS. 



Kellner at the Moeckern Experiment Station, 1 which include determinations 

 of the gain or loss of fat as well as of protein and hence afford a secure basis 

 for judgment as to the sufficiency of the energy supply. Including subsequent 

 slight corrections by Kellner, 2 the principal results as regards protein are sum- 

 marized in the following table : 



Gain or loss of protein by cattle — G. Kiihn and Kellner. 



No. of animal. 



Live 

 weight. 



Protein per day and 1, 

 Digestible in feed. 



300 pounds live weight. 

 Gain by animal. 



Crude 

 protein. 3 



True 

 protein. 4 



Protein. 



Fat. 





Pounds. 



Pound. 



Pound. 



Grams. 



Grams. 



II 



1,394 



0.65 



0.58 



-17.2 



+ 75.8 



Ill 



1,393 



.53 



.35 



-24.5 



+ 63.0 



IV 



1,386 



.53 



.34 



-25.9 



+ 20.4 



V 



1,327 



.75 



.60 



+21.8 



+106.6 



VI 



1,420 



.71 



.57 



+11.8 



+ 119.3 



XX 



1,481 



.80 



.65 



- 3.2 



+ 71.7 



A 



1,365 



.71 



.56 



+27.2 



+103.0 



B 



1,348 



.35 



.28 



-65.3 



. - 78.0 



If the very small loss of protein by ox XX may be regarded as falling 

 within the limits of experimental error, the eight experiments may be averaged 

 as follows : 



Animal. 



Digestible in feed. 



Gain by animal. 



Crude 

 protein. 



True 

 protein. 



Protein. 



Fat. 



Animals V, VI, XX, and A 



Animal II 



Pound. 

 0.74 

 .65 

 .47 



Pound. 

 0. 60 

 .58 

 .32 



Grams. 

 14.4 

 -17.2 

 -38.6 



Grams. 

 + 100.2 

 + 75.8 

 + 5.4 



Animals III, IV, and B 



It appears that approximately 0.6 pound of digestible true protein or 0.74 

 pound of crude protein per 1,000 pounds live weight was at least sufficient to 

 rather more than maintain nitrogen equilibrium when the total energy supply 

 in the ration was sufficient to cause a small gain of fat, while half this amount 

 of true protein or 0.47 pound of crude protein was manifestly insufficient. A 

 reduction to 0.35 pound digestible true protein or 0.53 pound digestible crude 

 protein in the cases of ox III and ox IV, even with a sufficient supply of non- 

 nitrogenous material to cause some gain of fat, resulted in a loss of protein 

 from the body, while in the case of ox B, with a slightly lower supply of true 

 protein and a materially lower one of crude protein and a ration materially 

 below the maintenance requirement, the loss of protein was still greater. The 

 considerable loss of protein by ox II is not readily explicable. 



Experiments upon the same subject were also made by the writer 5 in 1892- 

 1898, ehiefty upon rations of timothy or mixed hay, with the addition in Ex- 

 periment VII of starch, but also, in Experiment VIII, upon a ration consisting 



1 Die Landwirtschaftlichen Versuchs-Stationen, vol. 44, p. 257 ; vol. 47, p. 275. 



2 Die Ernahrung der Landwirtschaftliche Nutztiere, 5th ed., p. 411. 



3 Corrected for estimated loss of nitrogen in drying of feces. 



4 As reported in the original account of these experiments. 



5 Pennsylvania Experiment Station, Bulletin 42, p. 165. 



