172 THE BOOK OF BUTTER 



129. Effect of the individuality of the cow. It is 



thought that the milk of different cows varies more or 

 less, even though the animals may be fed and otherwise 

 handled in the same way. The period of lactation may 

 also be an important factor in the flavor of the milk. 

 Eckles and Shaw l state : "An abnormal odor and flavor 

 developed in the milk of certain cows when near the end 

 of the lactation period. This condition was not present 

 in the freshly drawn milk, but appeared within twelve 

 hours, even when the milk was held at 10 C." 



130. Effect of minor factors on storage. Salt is a 

 chemical compound that inhibits the growth of some 

 micro-organisms. Naturally the strength of the salt 

 solution is important. Regarding this McKay and Lar- 

 sen 2 assert, " Salt improves the keeping quality of but- 

 ter." Rahn, Brown, and Smith 3 write, " Salted butter 

 keeps better than unsalted butter, above the freezing 

 point as well as below it." Gray and McKay 4 report 

 the following result of their experimental work : " Butter 

 containing low percentages of salt kept better than did 

 butter of the same lot containing higher percentages of 

 salt." It was the common opinion at one time that butter 

 high in salt is very likely to become fishy. McKay 4 



1 Eckles, C. H., and Shaw, R. H., The Influence of the Stage 

 of Lactation on the Composition and Properties of Milk, U. S. 

 Dept. Agri., B. A. L, Bui. 155, p. 77, 1913. 



2 McKay, G. L., and Larsen, C., The Keeping Quality of 

 Butter, la. State Col. Exp. Sta., Bui. 71, p. 30, 1903 



3 Rahn, Otto, Brown, C. W., and Smith, L. M., Keeping Quali- 

 ties of Butter, Mich. Agri. Col. Exp. Sta., Tech. Bui. 2, p. 43, 

 1909. 



4 Gray, C. E., and McKay, G. L., The Keeping Qualities of 

 Butter Made under Different Conditions and Stored at Different 

 Temperatures, U. S. Dept. of Agri., B. A. I., Bui. 84, pp. 22-23, 

 1906. 



