THE CONCENTRATES 171 
is the only safe position to take towards whole screenings. Finely- 
ground screenings often make satisfactory and cheap feeds, and, if 
carefully ground, are not, as a rule, objectionable. Poisonous weed 
seeds, like corn cockle, are found in most screenings, but they are 
not ordinarily present in sufficient quantities to give rise to any 
Fig. 33.—Weeds growing from seed found in a mixed ‘‘dairy feed.” This contained 
100,000,000 weed seeds to the ton. The soil was sterilized, so that it is certain that every 
lant grew from a weed seed in the feed. Most samples of whole screenings contain still 
arger numbers of weed seeds. (Vermont Station.) 
trouble in stock feeding. Sheep and poultry appear to be able to 
destroy weed seeds of screenings more thoroughly than other farm 
animals, and do well on them (Fig. 33). 
Screenings are often used in the manufacture of mixed feeds 
and molasses feeds, in the latter case serving as absorbent for the 
