Foods and Feeding 



249 



tions of vegetable origin which had, according 

 to the ordinary methods of estimation, practi- 

 cally the same nutritive value. A ration of vege- 

 table food supplemented by bone ash proved much 

 inferior to another ration of 

 similar ' composition,' in which 

 three -eighths of the protein came 

 from animal food." * 



Fig. 82. A V-shaped water trough. 



Fig. 83. A shallow water trough. 



If the ducklings are confined in comparatively 

 small yards, it is best to provide some shade 

 for them, particularly during the hottest months. 

 Green food fed to ducks confined in yards should 

 be cut fine in a feed-cutter. Almost any green 

 succulent food will be readily eaten. Rye, clover, 

 alfalfa, Canada field peas, and corn make excel- 

 lent food if finely cut. Ducks will readily eat 

 the plant, stalk and all, in this condition, while 



* Summary of Bulletin No. 171, New York Experiment Station. 



