68 



MASS. EXPERIMENT STATION BULLETIN 158. 



objection to the use of screenings in proprietary stock feeds was due to 

 the fact that they contained manj^ whole weed seeds wliich passed through 

 the animal undigested and found their way on to tlie land ready to grow, 

 and thus added to the labor of keeping cultivated land free from weeds. 

 "With improved processes of manufacture the screenings are now mostly 

 finely ground and their germinating property destroyed. 



(1) Physical Appearance. 



Two lots of screenings were obtained from a commission merchant in 

 Milwaukee. Thej'' were quite similar in physical appearance. The fol- 

 lowing materials were identified in sample No. 1; light oats, oat hulls, 

 wheat, wheat refuse, smutted grain, yellow foxtail, green foxtail, corn 

 cockle, bindweed, flax, lady's thumb, charlock, wild mustard, rape, lamb's- 

 quarters, large smartweed, chaff of various sorts, wild sunflower, pigweed, 

 timothy, shepherd's-purse, chess, oat grass, wild oats, rye and corn, to- 

 gether with a few unidentified seeds. Both lots used must be considered 

 as of good quality for screenings, as they did not contain excessive amounts 

 of broken straw, chaff or dirt. 



(2) Chemical Composition. 



(3) Digestion Coefficients obtained with Sheep. 

 Lot I. 



Lot II. 



