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FOODS, IN RELATION TO RESPIRATION AND FEEDING. 335 
The oat-straw chaff of pen 4 was given as adding to the otherwise only 
succulent matter of the turnip, the bulk of solid matter which seems to be 
demanded particularly by ruminant animals. So small a quantity of this 
straw was eaten, however, that it need scarcely enter into our calculations. 
Turning to the results of pens 1, 2 and 8, it is seen that the weekly consump- 
tion of non-nitrogenous matter per 100 lbs. live weight of animal is, with the 
oil-cake as limited food, 9°8 lbs.; with the oats, 11°3 lbs.; and with the clover- 
chaff 13°1 lbs. Now, of these three descriptions of food, the oil-cake would 
contain by far the most of oleaginous matter, the respiratory and fat-forming 
capacity of which is about twice and a half as great as that of the starch 
series of compounds which would more abound in the oats. Hence we find 
that a less actual weight of non-nitrogenous substance was consumed with 
the oil-cake than with the oats. But to the reason just given, to which a part 
of the result was doubtless due, we might add that there was a comparatively 
large and somewhat excessive amount of nitrogenous matter consumed in the 
oil-cake pen, a part of which at least might serve the respiratory and fat- 
forming functions. Then, again, in pen 3, where clover-chaff was the limited 
food, the animals would consume a much larger amount of effete woody 
fibre than with either the oil-cake or the oats; in this pen therefore a larger 
gross weight of non-nitrogenous substance must be eaten to yield the same 
equivalent of that which is available for respiratory or fat-forming purposes 
than with either of the other foods. When therefore, allowance has been 
made for the different quantities and capacities of the available constituents 
in the several foods, it will be seen, that the equivalents of the available non- 
nitrogenous constituents consumed in the different cases, are in reality much 
more nearly identical, than the figures as they stand in the Table would 
indicate. But if we now turn to the column of the nitrogenous substance 
consumed under the same circumstances, we find that it varies, comparing 
one pen with another in this first series, nearly as much as from 1 to 24. 
In the second series (Table IV.) we have clover-chaff as the ad libitum or 
complementary food in all the pens, instead of Swedish turnips as in Series 1 ; 
and again, with the much larger amount of effete woody fibre, we have a 
larger gross amount of the non-nitrogenous substance consumed. The 
average of the four pens of this Series 2 is indeed almost identical with the 
amount where clover-chaff was employed in Series 1. Again, comparing one 
pen with another in this clover-chaff series, we have with the larger amounts 
of oleaginous matter supplied in the linseed and oil-cake, less of gross non- 
nitrogenous substance taken than with the barley or the malt, in which there 
is a proportionally larger amount of the starch series of compounds. When 
due allowance is made, then, for the different respiratory and fat-forming 
capacities of the several foods, we have again a closer coincidence than would 
at first sight appear, in the equivalents of the non-nitrogenous substances 
consumed in the different pens of this second series—as also when we com- 
pare this series with the former one. Turning now to the column of the 
nitrogenous substances consumed in this second series, we see that the gross 
amounts vary more than in those of the non-nitrogenous ; and more indeed 
‘than, according to any knowledge we at present possess, could be accounted 
for by a consideration as to the state in which the nitrogen existed in the 
severalpens. Comparing nowthe result of the one series with those of the other, 
although in the two cases the description of the larger portion of the food is 
widely different, and we have found that there is nevertheless considerable 
coincidence in the amounts of non-nitrogenous substance consumed, yet the 
columns of nitrogenous substance throughout the two series show a very 
great variation in the quantities of these consumed—amounting, indeed, in 
