648 Journal of Agricultural Research vol. vi, No. 17 



part of which was present as a constituent of the meat loaf and a part 

 as a constituent of the basal ration, supplying in all approximately 125 

 gm. of fat per subject per day. This was 94.6 per cent assimilated, 

 which for all practical purposes is identical with the digestibility of 

 butter found in a previous investigation, 1 93.9 per cent. 



Inasmuch as the subjects were allowed to eat of the basal ration 

 according to individual preferences, the energy value of the diet was not 

 uniform. It was found, however, that the subjects eating as much as 

 they wished received, on an average, 3,265 Calories daily, calculated from 

 the average daily consumption of protein, fat, and carbohydrates, and 

 the factors 2 commonly used in the determination of fuel values. In view 

 of the fact that over 130 gm. of protein, largely supplied by the meat 

 loaf, and over 3,200 Calories of energy were consumed daily, it is apparent 

 that the ration was eaten with relish. 



The digestibility of the total protein of the diet was found to be 87.3 

 per cent. The meat loaf supplied 82 per cent of the total protein con- 

 sumed, a much larger proportion than is ordinarily furnished by the 

 meat portion of a meal; consequently, greater accuracy is possible in 

 estimating the digestibility of the protein contained in the meat loaf. 



The digestibility of the protein of the meat loaf alone, 86.8 per cent, 

 differs little from the value of the digestibility of the entire ration. This 

 is due partly to the rather complete assimilation of the protein of the 

 basal ration and partly to the relatively small amount of protein derived 

 from this source. The value, 86.8 per cent, represents the digestible pro- 

 tein of the meat loaf, but it should closely approximate that for the 

 protein of the hard palates, since in the preparation of the loaf the pro- 

 portions used were 13.5 parts of hard palates to 1 part of flour. An 

 allowance may be made for the flour by assuming the protein from this 

 source to be 93.8 per cent 3 digestible. From the results of this investi- 

 gation, accordingly, it would seem that the protein of hard palates which 

 have been thoroughly cooked is somewhat less thoroughly assimilated 

 than that of the common cuts of meat. 4 



1 Langworthy, C F., and Holmes, A. D. Digestibility of some animal fats. U. S. Dept. Agr. Bui. 310, 

 22 p. 1915. 



2 Atwater, W. O., and Bryant, A. P. The availability and fuel value of food materials. In Conn. Storrs 

 Agr. Exp. Sta. 12th Ann. Rpt. 1899, p. 104. 1900. 



3 Woods, C D., and Merrill, L. H. Studies on the digestibility and nutritive value of bread at the Maine 

 agricultural experiment station, 1899-1903. U. S. Dept. Agr. Office Exp. Stas. Bui. 143, p. 33. 1904. 



4 Grindley, H. S., Mojonnier, Timothy, and Porter, H. C Studies of the egect of different methods 

 of cooking upon the thoroughness and ease of digestion of meat at the University of Illinois. U. S. Dept. 

 Agr. Office Exp. Stas. Bui. 193, 100 p. 1907. 



