APPETITE OF SWINE 
395 
rich standard calls for a definite amount of digestible protein, 
carbohydrate, and fat daily for a hundred pounds of live weight ; 
it pays little attention to the ratio of digestible or crude nu- 
trients although these are figured and presented in Plate XLIV 
from the requirements which Dietrich suggests. Dietrich in addi- 
tion gives the water requirement, but this is not considered at 
this time. These standards provide an interesting theme for 
discussion. 
In converting the Wolff -Lehmann standard and the Illinois 
or Dietrich standard to the crude nutrient basis we have as- 
sumed^® for the particular grain feeds used a digestibility of 
80 per cent for the protein (which really means we added one- 
fourth or 25 per cent to the digestible figures given to get those 
presented on Plates XLI and XLII) ; 91 per cent for the carbo- 
hydrates (this calls for an addition of practically one-tenth or 10 
per cent to the digestible figures given) ; and 70 per cent for the 
ether extract or fat (this calling for an addition of three-sev- 
enths or approximately 42.86 per cent) . We have likewise based 
the figures for the carbohydrate equivalent, assuming that one 
pound of crude fat is equal to 2.2 pounds of crude carbohy- 
drate; therefore the fats are simply multiplied by 2.2 and this 
is added to the carbohydrate figure — this giving the crude ear- 
bohydrate equivalent. All figures are reduced to the Amounts 
Consumed Daily to a Thousand Pounds Live Weight. 
Inasmuch as there is considerable variance in the digestibility 
of feeds, this depending upon the preparation of the feed, ani- 
mals used, and also the ways in which the feeds are mixed to- 
gether, it is deemed advisable to base the present paper upon 
crude nutrients rather than upon digestible ones; inasmuch as 
concentrated grains or their by-products were used entirely for 
the organic portion of the ration without any roughages what- 
soever, the use of the crude nutrients is all the more justified. 
The crude protein consumed daily to a thousand pounds live 
weight is given in curve form in Plate XLII. The striking fea- 
tures of this chart are : 
1. The close similarity and coincidence of the feed con- 
sumption curves determined by the free-choice fed pigs fed upon 
three different combinations of feed. 
3^Using as a basis figures from these sources: Forbes, B. B. ; 1914, Ohio 
Exp. Sta. Bulls. 172 and 271; Dietrich, William, and Grindley, H. S. : 1914< 
111. Agr. Exp. Sta. Bull. 170; Grindley, H. S., Carmichael, W. J., and Newlin, 
C. I.: 1914, 111. Exp. Sta. unpublished data; Jordan, Whitman Howard: 
Maine Agr. Exp. Sta. Rpt. 1886-87; Snyder, Harry: 1893, Minn. Agr. Exp. 
Sta,, Bui. 26 ; and Eward, John M., and Guernsey, S. C. 1910-11-12, Iowa 
Exp. Sta. Unpublished Data on Eighty Digestion Trials. 
