While in stable, the cow must also have plenty of pure air and sweet
water, and not be chilled in obtaining either. Without pure air,
the cow becomes debilitated and diseased, and the milk impure and
unwholesome. Impure water both taints and corrupts the product. A
proper temperature--certainly above freezing--should be kept up.
Remember, the cow standing still cannot resist cold as she could if she
were free to move about. It is cheaper to build warm stables--always
providing for perfect ventilation, the air coming in at the head and
passing off in the rear of the cow--and even to resort to artificial
heating, than to compel the cow to burn an extra amount of carbonaceous
food in her system to keep up the temperature of her body. Not only is
fuel cheaper than food, but the system of the cow cannot devote to milk
secretion the energy which is expending in secreting and consuming fat
to maintain a proper amount of vital heat.