CHAPTER VII 
CONDITIONS AFFECTING THE DIGESTIBILITY OF 
FEEDING STUFFS 
WE have already shown the effect of advanced stages of develop- 
ment of plants on their digestibility. Some other factors that 
influence the digestibility of feeding stuffs will now be considered. 
Different Classes of Farm Animals.—As might be expected 
from the differences in the digestive apparatus of the various classes 
of farm animals, these differ somewhat in their ability to digest cer- 
_ tain feeding stuffs, Concentrated feeds are digested to a similar 
extent by nearly all classes of farm animals, but this does not hold 
true in the case of coarse feeds. The digestion coefficients for meadow 
hay and oat straw obtained by Kellner in the case of steers and 
sheep will illustrate the differences met with.* 
Digestibility of Hay and Straw by Steers and Sheep, in Per Cent 
Meadow hay Oat straw 
Steers | Sheep || Steers Sheep 
Dry matter............ 65 | 62.|| 57 | 47. 
Crude protein scat eens 61 ‘57 32 | 19 
Batic ceutinis ictdoieehcles 61 57 || 43 50 
Fibers. yc 02a x ieeeas -64 | 61 63 49 
Nitrogen-free extract...} 70 69 58 49 
Hay or straw of the same origin was fed to both classes of ani- 
mals in these experiments. Greater differences are likely to occur 
where digestion coefficients of feeds of different origin are compared. 
Steers can, in general, digest bulky, coarse feeds better than sheep 
can, while ‘with easily digested feeds only minor differences occur in 
the digestion coefficients obtained with these classes of farm animals. 
Horses and other non-ruminants have a lower digestive capacity 
for coarse feeds than the ruminants. This is especially true as 
regards the fiber content of feeds. Through their more thorough 
mastication of roughage, and the fact that the feed is prepared for 
digestion by being softened in the paunch previous to the stomach 
digestion, the ruminants are able to better utilize the energy of the 
fiber in coarse feeds, like hay and straw, than are horses or pigs. 
The following average figures for digestibility of timothy, alfalfa 
1 Experiment Station Record 9, p. 509. 
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