204 The Feeding of Animals 



distinctions are involved in the classification of the 

 cattle foods in common use at the present time. 



The feeding stuffs of vegetable origin are generally 

 divided into four classes: (1) forage crops, consisting 

 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 seeds or grains which are the by-products 

 from the removal of other parts by some manufacturing 

 process. These are the commercial by-product feeding 

 stuffs. 



FORAGE CROPS 



The valuable forage plants of the United States 

 belong mostly to two families, the grasses (gramineae) 

 and the legumes (leguminosee) . June grass, red top, 

 timothy and the cereal grain plants are types of the 

 former; and the clovers, alfalfa (Fig. 3), the vetches, 

 and peas, of the latter. Whether in the pasture or in 

 tilled fields, few plants outside of these divisions con- 

 tribute 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 compounds 

 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 



