CHURNING 309 



of this type becomes greatly diluted with cream that is normal 

 in its churnability and causes no material disturbance in the 

 churnability of the whole churning. 



Certain cows when they have been in milk five to six, 

 months persist in yielding cream which churns with great dif- 

 ficulty, and the butter granules of which are exceedingly slow 

 in gathering. The difficulty is usually accompanied by very 

 great loss of fat in the buttermilk. 



The same difficulty is experienced frequently with cream 

 from old cows and from cows which have not been with calf 

 for a long time. This condition is usually intensified by the 

 feeding of dry roughage and certain kinds of grain. Examina- 

 tion of such cream invariably shows that it either is abnormally 

 viscous, or contains unusually small fat globules, or that its 

 butterfat is unusually hard, containing a low per cent of oleiri, 

 or a combination of two or all of these conditions. As ex- 

 plained under "Conditions Affecting the Churnability of Cream," 

 all of these conditions make the formation of butter granules 

 difficult and therefore retard the churning process. 



These conditions occur usually in the fall and early winter 

 when the cows are on dry feed and are well advanced in their 

 lactation. In some cases the abnormal condition of the milk 

 can be minimized by the addition to the feed ration of some 

 succulent feed, such as corn silage or roots, or some grain rich 

 in vegetable oil, such as linseed meal. The succulence increas- 

 es the milk flow and tends to reduce the viscosity. The grain 

 rich in vegetable oil increases the per cent of olein causing 

 the butterfat to be of softer character. In the majority of 

 cases, however, the cow refuses to respond to a change of feed 

 at the end of her period of lactation. After parturition the, 

 milk usually is normal again and the cream churns readily. 



In numerous cases the churning difficulties reported are 

 not due to any abnormal condition of the cream as produced 

 by the cow, but to faulty methods of manufacture. The cream 

 has undergone peculiar fermentations which cause it to become 

 abnormally viscous, a cream very low in butterfat is produced, 

 the churn is filled too full, or the churn revolves too fast or too 

 slow. 



