168 Milk Investigations at Garforth. [June, 



detail. The general conclusions drawn by Dr. Crowther are as 

 follows : — 



(i) Change from a highly nitrogenous diet to one relatively 

 poor in nitrogen causes secretion of a greater quantity of milk, 

 but of milk rather poorer in fat — the change in the fat-content 

 being much more pronounced in the morning than in the evening 

 milk. Presumably, therefore, the reverse change — i.e., from a 

 diet poor in nitrogen to one relatively rich in nitrogenous con- 

 stituents — would effect an improvement in the quality of the 

 milk, though accompanied by a relative decrease in the yield, 

 as indeed was found to be the case by direct experiment. 



(2) Concentrated food given only in the morning tends to 

 increase the fat-content of the morning milk, but there is 

 apparently no analogous improvement in the evening milk. 

 (Dr. Crowther here states that the conclusions drawn from 

 the experiments in 1901 and 1902 are thus fully confirmed.) 



(3) Concentrated food given only in the evening also tends to 

 increase the fat-content of the morning milk, but has apparently 

 little or no effect on the evening milk. (4) The above-mentioned 

 changes are not of a pronouncedly temporary nature, since they 

 persist without appreciable diminution for fully five weeks after 

 the change of treatment. (5) The effects of sexual excitement 

 are, as a rule, most pronounced on the milk-yield, which, 

 in general, at first shows a marked diminution, followed usually 

 at the next milking by a yield well above the average. The 

 fat-content is usually at first considerably diminished, but at 

 the following milking is sometimes abnormally high, sometimes 

 abnormally low. The fat-content of the milk yielded on the 

 two or three days immediately preceding the outward mani- 

 festation of sexual excitement is in nearly every case decidedly 

 above the average. In most cases the disturbing effect is not 

 appreciable after two, or at the most three, succeeding milkings. 

 Results at variance with these conclusions were, however, 

 obtained with a few cows. (6) Provided the milking be 

 satisfactorily performed, the individuality of the milker has no 

 appreciable influence on the milk-yield or the quality of the milk. 

 (7) The influence of climate apparently varies considerably 

 with different cows. The change from an equable to either a 

 decidedly low or a decidedly high temperature tends in the 



