66 PRINCIPLES OF FEEDING FARM ANIMALS 



the bloom had a coefficient of 43 per cent. In general, the 

 older and tougher the plant the less digestible is the crude 

 fiber. 



Digestibility of Fat. — Owing to the inaccurate methods 

 of analysis, the determinations of the digestibihty of fat 

 usually are less exact than those of any of the other nutrients 

 excepting mineral matter. 



The digestibihty of the fat of the concentrates is greater 

 than that of the roughages. Of the concentrates, the fats 

 from packinghouse by-products, oil by-products, cereal by- 

 products, and oil-bearing seeds have the highest coefficients 

 of digestibihty, in most cases being from 80 to 98 per cent. 

 The fats of the other concentrates are usually from 65 to 90 

 per cent digestible. 



In the roughages, the fats of com fodder and stover have 

 the highest coefficients of digestibility, — 67 to 74 per cent. 

 The straws are lowest, — 30 to 39 per cent. 



In general, the digestibihty of fat increases with the 

 amount of fat in the feed, and decreases with the amount 

 of crude fiber. 



FACTORS AFFECTING DIGESTIBILITY 



There are certain factors which may affect the digestibihty 

 of feedingstuffs, either favorably or unfavorably. Also, 

 there are certain factors which sometimes are said to affect 

 the digestibihty which, as a matter of fact, have no influence 

 whatever. Obviously a knowledge of these factors and their 

 influence, if any, upon the digestibihty is of considerable 

 practical importance. 



Species of Animal. — The species of animal may have 

 considerable influence upon the digestibihty of a feeding- 



