220 THE FEEDING OF ANIMALS 



of the stem and leaves of herbaceous plants, either in 

 green or air-dry condition, to which is attached in some 

 cases the partially formed or wholly mature seed or 

 grain; (2) roots and tubers, or the thickened under- 

 ground portions of certain plants; (3) seeds or grains; 

 (4) parts of a plant which are the by-products from the 

 removal of other parts by some manufacturing process. 

 These are the commercial by-product feeding-stuffs. 



FORAGE FOODS 



303. Classes of forage crops. The valuable forage 

 plants of the United States belong mostly to two families, 

 the grasses (Graminese) and the legumes (Leguminosse). 

 June grass, red-top, timothy and the cereal grain plants 

 are types of the former; and the clovers, alfalfa, 

 the vetches, and peas, of the latter. Whether in the 

 pasture or in tilled fields, few plants outside of these 

 divisions contribute materially to the supply of high- 

 class fodders. The most essential difference between the 

 members of these two families of plants when considered 

 as feeding-stuffs is the larger proportion of nitrogen com- 

 pounds in the legumes. It is characteristic of all legumes 

 that their proportion of protein is high as compared with 

 any other forage crops, and for this reason they are 

 greatly prized on dairy farms. The fact that they are 

 regarded as increasing materially the nitrogen supply 

 of the farm from sources outside the soil also adds to 

 their value. 



304. Green vs. dried fodders; conditions of drying. 

 Nearly all of the herbaceous plants that are grown for 

 consumption by farm animals may be fed either in a green 

 or dry state. Oats, maize, clover, alfalfa, and other spe- 



