MILK PRODUCTION 481 



576. Feed cost of exercise. Attention was called in the 

 discussion of the maintenance requirement in Chapter VIII 

 (391) to the very marked effect of muscular exertion in increas- 

 ing the katabolism, especially of body fat or of the non-nitroge- 

 nous ingredients supplied by the feed. It has been frequently ar- 

 gued from this fact that the amount of exercise allowed to dairy 

 cows should be restricted as much as possible. Not a few dairy- 

 men indeed have gone so far as to confine their cows entirely, 

 reasoning that since the object of their business is to convert 

 feed into milk any diversion of it to the support of muscular 

 exertion was a waste. This, however, is a very narrow and 

 inadequate view of the subject. Most authorities on dairying 

 regard a moderate amount of exercise for dairy cows as bene- 

 ficial. Thus Martiny 1 in 1871 cites five authorities on this 

 point and expresses the opinion that exercise and moderate 

 work increase rather than decrease the yield of milk, while 

 severe work has an unfavorable effect upon both the yield and 

 quality. Similar opinions are expressed later by C. F. Miiller, 

 Fleischmann, Kirchner, Kb'nig and Von Klenze. These earlier 

 data are of the nature of more or less empirical observations 

 rather than of actual experiments. 



577. Morgen's investigations. Of actual experiments upon 

 the influence of muscular exertion upon milk production, 

 those of Morgen 2 at the Hohenheim Experiment Station are 

 the most convincing because they were made under strictly 

 comparable conditions and especially because the relative 

 amounts of work performed in the different periods were 

 determined. 



The two Simmenthal cows employed were accustomed to 

 being used for draft. The work was done at a slow walk upon 

 the sweep power dynamometer used by Wolff in his experiments 

 upon work production by the horse (386 a, 670, 779), the amount 

 of work performed being regulated in part by the resistance of 

 the dynamometer and in part by the number of hours of work 

 required, so that approximately single, double and quadruple 

 work was done. The ration fed, which was a liberal one, was 

 unchanged throughout the trials. The experiment consisted 

 of 1 1 periods, approximating two weeks 3 each of alternate rest 



1 Die Milch, Part I, pp. 345-435- * Landw. Vers. Stat., 51 (1899), 117. 



3 Eleven to twenty-six days. 

 2 I 



