DIGESTIBILITY OF FEEDING STUFFS 65 
Even swine are able to digest considerable amounts of vegetable 
fiber. Direct experiments have shown that the digestion coefficients 
for fiber obtained with this class of animals are as follows: In the 
case of wheat bran, 39 per cent; wheat shorts, 37 per cent; barley, 
49 per cent; corn, 39 per cent; corn and cob meal, 39 per cent; 
cracked wheat, 60 per cent; pea meal, 78 per cent; green oats and 
vetch, 49 per cent. These figures, in most cases, compare favorably 
with the average digestibility coefficients for the respective feeds 
obtained with steers or sheep. 
' Breeds.—Different breeds of the same class of farm animals do 
not appear to differ appreciably in their digestive capacity, nor do 
individual animals of the same breed differ in this respect, so long 
as the animals compared are in good health and have good teeth. 
Very young as well as old animals are handicapped in eating whole 
dry grains, on account of their inability to chew their feed well, and 
it should be fed wet or ground to such animals. Differences in the 
digestibility of feeds have sometimes been found in the case of 
individual animals, but there does not seem to be any regularity in 
the variations observed, and these are, therefore, likely to be acci- 
dental and due to errors of experimentation. 
Age.—Age does not seem to affect the digestive capacity of 
animals whose digestive apparatus is fully developed, nor does 
a fair amount of work influence the digestion, provided that this is 
done at a moderate rate, like ordinary work of horses, mules, and 
oxen. Work done at a rapid pace, on the other hand, is likely to 
diminish the digestibility of the rations fed. 
‘The various conditions bearing on the chemical.composition of 
plants which have already been discussed are also of importance in 
so far as they affect the digestibility of plants. Among other factors 
that might be supposed to influence the digestibility of feeding 
stuffs, besides those already mentioned, are the following: 
Quantity of Feed—The quantity of feed does not appear to 
appreciably affect its digestibility. It should be said, however, that 
the testimony on this point is somewhat conflicting. The results of 
early experiments by Wolff and others, indicating a similar digesti- 
bility of small and large rations, have not been corroborated by more 
recent work. ‘It seems reasonable to suppose that the digestive fluids 
will vary to a certain extent, both in composition and amounts, with 
the character of the rations fed, in case of herbivora, as found to be 
the case with carnivora in the brilliant investigations by the Russian 
physiologist Pavlov. There is some evidence with herbivora which 
*“ Work of the Digestive Glands,” London, 1910. 
5 
