Station Tests with Feeds for Dairy Cows. 427 



fourteen- day periods just preceding or following a change in the 

 roughage supplied. 



Total yield of milk, four cows, 14 days. 



On hay 1,212 pounds. 



Changed to silage and hay 1,294 pounds. 



An increase of 82 pounds, or 7 per cent. 



On silage and hay 1,200 pounds. 



Changed to hay 1,100 pounds. 



A decrease of 100 pounds, or 8 per cent. 



We observe that when the cows were changed from hay to silage 

 and hay there was an increase of 7 per cent, in the milk flow, and 

 when changed back a shrinkage of 8 per cent. There was no 

 difference in the composition of the milk because of the different 

 feeds. Jordan concludes: "In this experiment the addition of 

 silage to the ration resulted in a somewhat increased production 

 of milk solids, which was not caused by an increase in the digesti- 

 ble food material eaten, but which must have been due either to 

 the superior value of the nutrients of the silage over those of the 

 hay or to the general physiological effect of feeding a greater 

 variety of foods. In other words, 8.8 pounds of silage proved to 

 be somewhat superior to 1.98 pounds of hay (mostly timothy), 

 the quantity of digestible material being the same in the two 

 cases. . . . Assuming the digestible matter of hay and silage 

 to be of equal value, pound for pound, when hay is worth $10 

 per ton, silage of the kind used in this experiment would be 

 worth $2.25 per ton. But this silage contained more water than 

 the average. . . . Had it been of average quality, then the 

 ton value reckoned on the above basis would be $2.62. But in 

 this case we should give the silage the credit of the increased 

 milk production, which seems to have been at the rate of 85 

 pounds of milk to each ton of silage. 77 (390-91) 



655. Silage versus fodder corn. At the New Jersey Station 1 

 Yoorhees and Lane conducted a trial with silage and fodder corn 

 for milk production. 



A field of fifteen acres was planted to corn in rows three feet 

 six inches apart, with the stalks eight inches apart in the row. 



1 Bui. 122. 



