504 



NUTRITION OF FARM ANIMALS 



TABLE 139. INFLUENCE OF PROTEIN SUPPLY ON MILK PRODUCTION 

 (Results per day and head) 



Although the low protein rations were able to support a con- 

 siderable milk production without causing the body protein to 

 be drawn upon materially, nevertheless, a more liberal supply 

 of digestible protein was accompanied by a distinctly greater 

 production of both total milk solids and milk protein. 



Morgen's investigations. The extensive investigations of 

 Morgen and his associates l upon milk production by sheep 

 include a large number of trials in which an exchange between 

 comparatively pure protein on the one hand and starch or oil 

 on the other was made in the rations. The results, therefore, 

 afford valuable data regarding the influence of the protein 

 supply as distinguished from the possible effects of associated 

 factors. In nearly all instances the ration of the low protein 

 period contained a considerable surplus of digestible protein 

 above the total of milk protein plus maintenance protein. In 

 the following table, computed by the writer, the experiments 



1 Landw. Vers. Stat., 61 (1904), i ; 62 (1905), 251 ; 64 (1906), 93 ; 66 (1907), 63. 



