76 BUTTER-MAKING. 
decrease in the volatile fats, and makes butter noticeably 
harder and more tallowy in appearance. 
Environment.— Unfavorable environmental conditions im- 
posed upon a cow, such as sudden changes in temperature, 
storms, impure surroundings, and ill-ventilated barns, are 
certain to decrease the flow of milk; and if they are continued a 
few days, the percentage of fat in the milk will decrease also. In 
a general way it might be said that any unfavorable condition 
which causes a decrease in the quantity of milk will cause a 
slight increase in the percentage of fat during the first few days. 
But if the cow is surrounded with these unfavorable conditions 
for any length of time, the percentage of fat will again decrease. 
It is possible, however, by ill treatment, to diminish the fat- 
content greatly. 
Exercise, also, affects the yield of milk, as well as the quality. 
Uninterrupted, long confinement in a stall is detrimental to 
a cow's health. For a time it shows no effect upon the quan- 
tity and quality of the milk, but eventually it will decrease 
both. However, many Danish dairy farmers keep their cows 
in the barn all winter, without letting them out for exercise, 
and it is said that this confinement has apparently no effect 
upon the quantity and quality of milk. But a proportion- 
ately large number of their cows are infested with tubercu- 
losis. Whether this is due to lack of fresh air and exercise, the 
authors cannot say. 
Too much exercise is adverse to producing the most and 
best milk. If a cow is kept in the barn every day, half an 
hour’s exercise, preferably out of doors, when weather permits, 
‘seems to give good results. A small box-stall for each cow, or 
.a well-bedded shed for them to stand or lie down in after feeding, 
are favorable conditions for getting the proper amount of 
exercise, especially during cold weather. 
Change of location, fright, sudden shocks, and nervousness 
are conditions from which the cow must be kept, in order to 
do her best as a milk-producing animal. 
