1896.] Relative Efficiency of Animals as Machines. 793 
one-fourth as much proteid matter in their feed, have a de- 
cided advantage in utilizing energy in their increase, with less 
waste in excreta, and a comparatively small expenditure of 
energy is required to keep the machine in working order. 
A comparison of the results with the pigs fed on barley 
meal and the “ analyzed fat pig” with a highly nitrogenous 
diet, will furnish quite as striking an illustration of the influ- 
ence of proteid food, as the conditions are less complex from 
the absence of coarse fodder in the rations. 
The “ analyzed fat pig ” consumed more dry substance, and 
nearly twice as much proteid matter, to make 100 pounds in- 
crease in live weight as the pigs fed on barley meal alone, but 
less energy was utilized in its increase, containing less dry 
substance and decidedly more was lost in excreta and a larger 
amount was required in repairs of the system. 
TABLE 4. 
The energy of food consumed by different animals to produce a given increase 
is expended as follows, under conditions above noticed. 
|In hk and 
. Lost in ex- jother physio- 
Inincrease. ano logical pro- 
cesses. 
Per cent. Per cent. Per cent. 
Oxen 12 28 60 
Sheep 16 23 61 
Pigs 36 14 50 
‘ Analyzed fat pig” 29 18 52 
Guernsey { April 20 36 43 
wW May 21 35 44 
The pigs fed on barley meal with their comparatively simple 
organs of nutrition, require less dry substance of feed and less 
energy to make a given increase than the ruminants with 
their complex nutritive machinery and large amount of 
coarse fodder in their rations which they are fitted to utilize ; 
but pigs and ruminants are alike in failing to give as large 
returns in profitable increase with an excess of proteids in 
their feed. 
