Influence of Peed on Milk. 443 



of butter. A number of investigators have studied the vari- 

 ations in hardness, melting point, volatile fatty acids, etc., of 

 butter-fat, due, it is generally supposed, to the different feeding 

 stuffs employed in nurturing the cow. While each investigator 

 has arrived at certain conclusions seemingly warranted by the 

 trials he has conducted, on classification these findings show little 

 agreement, so that Frear, J studying all the available data, was 

 forced to write: "They do not, however, suffice either for the 

 framing of a theory as to the relation of the several food constit- 

 uents to the fats of the milk, or for the quantitative measure of 

 the influence of a given food." 



As with scientists, so with practical feeders, we can find them 

 stating with much assurance that this or that particular feed has 

 this or that influence on the character of the butter made while 

 feeding it; when we classify these opinions, however, we find 

 them discordant and standing in opposition on the same article. 



As to cotton- seed meal there is fairly uniform agreement that 

 it makes a hard butter; while often deleterious, therefore, it may 

 be useful in firming butter required for the summer trade. (For 

 the influence of cotton- seed meal on butter see Article 217. ) The 

 changes in the quality of butter due to length of time from calv- 

 ing are generally greater than those wrought by any special sys- 

 tem of feeding. As originally shown by Nilson, 2 fat from fresh 

 cows contains a larger amount of volatile fatty acids than is found 

 at any later stage of the lactation period; as a result, butter 

 from such cows has a high flavor, comparatively speaking, while 

 that from strippers is deficient in flavor and of Jallowy consist- 

 ence. 



(e) Feed Influences on Flavor and Odor of MUk or Its Derivatives. 



678. Flavors of milk, butter, etc. Besides the variations already 

 referred to which are supposably measurable by the chemist, 

 there are immeasurable ones which may exert a potent influence 

 on the quality of milk and its products, these being perceived by 

 the sense of taste or smell usually by the former. Certain articles 

 eaten by cows leeks, onions, turnips, etc. give flavors detected 

 . Science, 1893. * Kgl. Landtbruks Ak. Handl., 1885, 45. 



