14 



milk and buttermilk were made and samples of butter were 

 reserved for future examination. 



The comparative hardness of the butter was determined by 

 Prof. C. L. Parsons, by means of the apparatus described 

 in Bulletin No. 13 — that is, by recording the depth of pen- 

 etration of a glass rod dropped from a given height. The 

 softer the butter, the further the rod will penetrate. The 

 changes in food, such data as may be of general interest as to 

 churnabilitv, loss of fat in skimmilk and buttermilk, and 

 hardness of butter are given in the following table. 



The character of the butter from the different groups was 

 practically -constant with the exception of hai-dness. In hard- 

 ness there were several sharp variations. With Princess Leto 

 and Pilot's Lily the change from a heavy grain ration resulted 

 in a much softer butter. With Maramee the substitution of 

 corn meal for gluten and cotton-seed meal resulted in decidedly 

 hardening the butter. Corn meal usually produces butter of 

 a firm texture, but cotton-seed meal has the same tendency in 

 a greater degree and might have been expected to balance the 

 softening influence of gluten. It would seem probable that 

 the very wide nutritive ratio of the ration fed in period 3 

 should be credited with a part of this effect. With Chin- 

 chilla, Jr., and Frost, Jr., the change to oat hay resulted in 

 a very much softer butter. Although the butters from rations 

 containing oat hay were generally softest, it is doubtful if the 

 whole of the variation in this instance is traceable to it. 



A study of the figures given in relation to the amount of 

 fat lost per pound of butter recovered and the pounds of milk 

 required per pound of butter, may be of interest. They are 

 to a certain extent an illustration of the differences between 

 the four breeds of cows. The approximate amount of butter 

 from each cow can be easily calculated by reference to tables 

 1, 2, 3, and 4. The figures show what wide variations exist 

 between different cows and herds. 



