258 THE CEREALS IN AMERICA 



warrants it. The surface area of the silo should be such tha: 

 the silage will be fed rapidly enough to prevent decay. It 

 should never be more than ten square feet per cow, five is 

 better ; while seven and a half gives good results. 



The riper the silage, the less weight the silo will hold. The 

 higher the silo and the greater the diameter, the more weight 

 the silo will hold. The weight and keeping quality will depend 

 also upon the manner of filling. The material should be evenly 

 distributed and the silage next the sides of the silo thoroughl) 

 packed by tramping in order to overcome resistance offered bj 

 the sides. The more slowly the silo is filled, the more it will 

 hold. A silo sixteen feet in diameter and thirty feet high will 

 hold, w^hen continuously filled with suitably ripened maize, 

 about thirty-three and a third pounds of silage per cubic foot, 

 or about ico tons of silage. A cubic foot of such silage is a 

 standard daily ration for a cow in milk. The capacity of the 

 silo required may be calculated in cubic feet by multiplying the 

 number of animals to be fed by the days of feeding desired. 

 Twelve tons of suitably ripened maize per acre is a good yield ; 

 eight to ten tons per acre is a safer estimate when calculating 

 the land to be planted in order to fill the silo. 



347. Losses in the Silo. — Babcock and RusselP have shown 

 that the changes which take place in the silage are not wholly 

 due to bacteria, but partly, at least, to the respiratory activity of 

 the yet living protoplasm of the plant tissue. The loss due to 

 respiratory activity was shown to amount to about one per cent 

 of the total weight of the silage, and was due to the carbonic 

 acid (COo) gas evolved. King has shown that the unavoidable 

 losses may amount to from two to four per cent.^ These are 

 the losses in feeding value which cannot be prevented with a 

 silo of the very best construction, filled in the best possible 

 manner. The losses not due to respiratory activity are due to 



1 Wis. Rpt 1901, pp. 177-184. 

 i Wis. BuL 83 (1900), p. 64. 



