Ventilation — continued

he must have a healthy herd. It is equally apparent that in order to have a healthy herd, an abundance of pure air must be supplied as well as an abundance of pure food. They are set down here in the order of their importance, since as stated, pure air is more vital than pure food and, in quantity, requires to be furnished in doubly the amount. Suppose you own a herd of 40 Holstein cows. You would not think of giving these cows from one-quarter to one-half as much feed and water as would be required to keep them either healthy or productive. The thought would be absurd. But if you fail to provide a system of ventilation which will give these same animals the proper amount of pure air, then you have failed to the same degree as though you had deprived them of adequate feed and water. True, without the proper pure air supply, they might not die, at least for a long time, but these same cattle would continue to live for a considerable length of time only half fed and half watered. Cattle may be starved by depriving them of a proper supply of pure air just as they would be starved by a lack of food or water. The only difference is that it is readily detected if the herd is starving because of a lack of food, where it is not so easily determined that they are starved by a lack of pure air. You have doubtless noticed a rough, scrawny herd turned out to pasture in the spring, thin, lifeless and with the appearance of having been poorly kept. The natural thought would be that this condition was due to insufficient food and water but a careful analysis will more frequently prove a lack of sanitation, insufficient sunlight and little or no ventilation. Note the improved appearance of the same herd 30 days later. Too often this change is attributed to the green pasture afforded the herd and not often enough to the fact that out-of-doors the herd has the opportunity to obtain in quantities the pure air of which it had been deprived during the winter in a poorly ventilated barn. Page One Hundred Fifty-seven