112 MAINE AGRICULTURAL EXPERIMENT STATION. 



oils very decidedly affected the melting point of butter fat while 

 others were without much effect. Sesame oil produced a butter 

 fat with a high melting point and almond and cocoanut oils had 

 very little eft'ect on the product which had a normal melting 

 point. Spier, in discussing his work of feeding milch cows, 

 states that nitrogenous foods such as cottonseed cake produce 

 farm butters with high melting points, while starchy or carbon- 

 aceous foods like sugar meal make soft butters. These state- 

 ments are true as applied to those two materials, but if the hard- 

 ness of the butter is influenced wholly by the nitrogenous and 

 carbonaceous matter of the rations, then it is difficult to explain 

 why corn meal, a carbonaceous food, will make a harder butter 

 than some gluten and linseed meals that are highly nitrogenous 

 but contain quite large percentages of fat. 



Cottonseed meal which invariably produces hard butter is not 

 very different in the food elements it contains from the old 

 process linseed meals and some of the glutens from which the 

 starch has been quite completely removed, and these latter prod- 

 ucts, when they contain as much fat as cottonseed meals usually 

 do, make soft butters. 



A chemical examination of the fats of these three foods may 

 offer a possible explanation. Crude cottonseed oil is found to 

 contain c[uite a quantity of vegetable stearin, so-called, which is 

 separated from the cotton oil of commerce by cold and pressure 

 and used largely for making lard and butter substitutes. Its 

 fatty acids have a high melting point (38° C.) and its general 

 character is not unlike sesame oil which has been found to pro- 

 duce hard butter when fed to cows. Corn oil on the other hand 

 contains practically no stearin, and according to Hopkins* is 

 about 45 per cent olein and 48 per cent linolein, w^hile linseed 

 oil is 80 per cent linolein. The fatty acids of these two oils are 

 liquid below zero Centigrade; linolein being liquid at — 18° C. 

 There seems to be sufficient difference in the character of the 

 fats to account for the changes in the butter if one wishes to 

 attribute the variation to the fat of the food. It is possible, 

 however, that the proteids of the food play an important part in 

 the formation of milk fat and have an important bearing on the 

 hardness of the butter, but it is also evident that the oils of the 



* Illinois station Bulletin 52. 



