106 PRINCIPLES OF FEEDING FARM ANIMALS 



usually are highly nutritious in nature. Examples of 

 common concentrates are corn, oats, the oil meals, mid- 

 dlings, and tankage. 



Concentrates often are divided into '' nitrogenous " and 

 "non-nitrogenous " concentrates upon the basis of their pro- 

 tein content. Nitrogenous concentrates are high in digestible 

 protein. They usually contain 11 per cent or more of digest- 

 ible protein. Examples are tankage, the oil meals, and 

 middlings. Non-nitrogenous concentrates are low in digest- 

 ible protein and high in digestible carbohydrates and fats. 

 They are often spoken of as carbonaceous concentrates. 

 They usually contain less than 11 per cent of digestible 

 protein. Examples are corn, oats, and barley. 



Roughages may be defined as feedingstuffs which contain 

 a relatively small amount of net energy (or digestible nu- 

 trients) in a large bulk. They contain a large percentage of 

 crude fiber. Roughages usually contain less than 40 therms 

 of net energy per 100 pounds, although there are a few 

 exceptions. Nitrogenous roughages are relatively high in 

 digestible protein. They usually contain 6 per cent or 

 more of digestible protein. Examples are clover, alfalfa, 

 and soy-bean hay. Non-nitrogenous roughages are relatively 

 low in digestible protein. They usually contain less than 

 6 per cent of digestible protein. Examples are timothy 

 hay, corn stover, and oat straw. 



