24 HOW TO BUILD A SILO. 



On the Size of Silo Required. 



In planning a silo the first point to be decided is how large it 

 shall be made. We will suppose that a farmer has a herd of 

 twenty-five cows, to which he wishes to feed silage during the 

 winter season, say for 180 days. We note at this point that silage 

 will not be likely to give best results with milch cows, or with 

 any other class of farm animals, when it furnishes the entire 

 portion of the dry matter of the feed ration. Variation in the size 

 of the animals will determine whether each cow is to receive 

 20, 30 or 40 pounds per day. As a rule, it will not be well to 

 feed over forty pounds of silage daily per head. If this quantity 

 be fed daily, on an average for a season of 180 days, we have for 

 the twenty-five cows 180,000 pounds, or ninety tons. On account 

 of the fermentation processes taking place in the silo, we have 

 seen that there is an unavoidable loss of food materials during 

 the siloing period, amounting to, perhaps, 10 per cent; we 

 must, therefore, put more than the quantity given into the silo. 

 If ninety tons of silage is wanted, about one hundred tons of 

 fodder corn must be placed in the silo; we figure, therefore, that 

 we shall need about four tons of silage per head for the winter, 

 but, perhaps five tons per head would be a safer calculation, and 

 provide for some increase in the size of the herd. 



Corn silage will weigh from thirty pounds, or less, to toward 

 fifty pounds per cubic foot, according to the depth in the silo 

 from which it is taken, and the amount of moisture which it 

 contains. We may take forty pounds as an average weight of a 

 cubic foot of corn silage. One ton of silage will, accordingly, take 

 up fifty cubic feet; and 100 tons, 5,000 cubic feet. If a rectangular 

 one-hundred-ton silo is to be built, say 12x14 feet, it must then 

 have a height of 30 feet. If a circular silo is wanted the following 

 dimensions will be about right: Diameter, 14 feet; height of silo, 

 30 feet, etc. In the same way, a silo holding 200 tons of corn 

 or clover silage may be built of the dimensions 14x18x40 feet, 

 16x16x39 feet, or if round, diameter, 18 feet, height, 37 feet, etc. 



Since the capacity of round silos is not as readily computed 

 as in case of a rectangular silo, we give on following page a table 

 which shows at a glance the approximate number of tons of silage 

 that a round silo, of a diameter from 8 to 20 feet, and 20 feet to 

 50 feet deep, will hold. 



Table III shows readily how much silage is required to keep 



