
$2 STORRS AGRICULTURAL EXPERIMENT STATION. 
remain uncut until after the blossoming stage, the plant will 
increase rapidly in woody fiber, and decrease relatively in 
the amount of digestible protein. 
Digestibility.—’The composition of a fodder is not the full 
measure of its value. A part only of each of the nutrients, 
protein, fat, etc., becomes available to the animal, hence the 
amount of food materials actually digested or extracted from 
the food eaten becomes an important factor in estimating its 
value. The composition of the fodder, the degree of maturity 
at which it is harvested, and the kind of animal are the princi- 
pal factors modifying the digestibility of feeding stuffs. 
The leguminous fodders as a class (with the possible excep- 
tion of red clover) are more digestible than the grasses, as 
shown by a large number of digestion experiments made both in 
this country and in Europe. It isa common fact, if not a gen- 
eralrule, that the larger the proportion of protein and the smaller 
the proportion of starchy materials, and especially of woody fiber 
contained in any feeding stuff, the larger will be the proportion 
of the principal nutrients digested by the animal. Hays, 
straws, cornstalks, and the like contain considerable amounts 
of material known as ‘‘ woody fiber’’ or lignin, which is not 
easily ground up in chewing and resists the action of the diges- 
tive fluids. These substances encase more or less of the valu- 
able nutrients—the protein, fat, starch, etc.—and hinder the 
action of the digestive fluids upon them. Hence, such coarse 
' fodders are much less digestible than those which have less 
woody fiber. : 
The degree of maturity of the crop has a marked effect upon 
its digestibility. Soon after the blossoming stage the propor- 
tion of woody fiber, including the lignin, increases rapidly. 
This tends to encase the more digestible portions and to prevent 
their being acted upon freely by the digestive fluids or by the 
mechanical processes of digestion: } 
Different classes of animals digest food materials somewhat 
differently. The horse, for example, does not digest coarse 
fodders as completely as do the ruminants. It has been found 
by numerous experiments that the ruminants or cud-chewing 
animals, such as the cow and the sheep, digest their food 
essentially alike, so that the results of digestion experiments 
with sheep are fairly applicable to all cattle. 

