342 THE FEEDING OF ANIMALS 



with any definiteness just what influence all the various 

 feeding-stuffs have upon the chemical and physical 

 properties of butter. Experimenters are fairly unani- 

 mous, however, in concluding that the liberal feeding 

 with cottonseed or cottonseed meal has the effect of 

 raising the melting-point of butter and of diminishing 

 the percentage of the volatile fatty acids. On the other 

 hand, when gluten meal rich in oil has been introduced 

 into the ration in generous proportion, the butter has 

 been foimd to melt at a lower point, and appeared softer. 

 Certain chemical reactions indicate that this decrease in 

 the melting-point has been accompanied, in some cases at 

 least, by an increase in the butter of olein, a fat which is 

 a prominent constituent of olive oil, and is liquid at 

 ordinary temperatures. One set of experiments, where 

 gluten meal with different proportions of oil was used, 

 appears to warrant the conclusion that the softening of 

 the butter from feeding this material is not marked when 

 its percentage of fat is small, as is the case with some 

 brands of gluten meal at the present time. The conclu- 

 sion which has been reached as a result of some experi- 

 ments, that gluten meal causes softer butter than corn 

 meal, the fats and other compounds in the two feeds 

 being similar in kind, is wholly irrational unless we 

 conclude that the larger quantity of fat fed in the former 

 is the cause of its specific influence. In a few cases where 

 various oils were fed in liberal quantity the butter is 

 reported to have varied in ways corresponding to the 

 composition of the oils, a result not at all improbable. 



In looking over the record of investigations along 

 this line it is found that food rich in sugar and other 

 soluble carbohydrates is credited with producing soft 

 butter, potatoes are charged with the same effect, and 



