4 BULLETIN 507, U. S. DEPARTMENT OF AGRICULTURE. 



portion ascribable to the fat supplied by the basal ration to repre- 

 sent the undigested portion of the fat studied. The significance of 

 such values, in discussing problems of dietetics and the theoretical 

 and other considerations having to do with metabohc products in 

 feces, are fully discussed in earlier publications.^ 



DIGESTION EXPERIMENTS. 



CHICKEN FAT. 



Although chicken fat as such is not available in quantity in most 

 markets the very large demand for poultry, especially mature poultry, 

 would indicate a very considerable consumption of the fat along with 

 the chicken meat. Little information, however, as to its digestibility 

 and nutritive value has been found in a survey of the literature. In 

 studies of the digestibility of fish and poultry, Milner^ found that 

 chicken fat eaten as an integral part of poultry in a simple mixed diet 

 was 97 per cent digested. 



Several pounds of chicken fat, which had been taken in small quan- 

 tities from fat birds drawn at the market for those not desiring the 

 excess fat, were procured. It was passed through an ordinary meat 

 grinder and heated in a double boiler to a temperature higher than 

 its melting point, after which the fat was easily separated from sur- 

 rounding tissues by straining. 



For use in the digestion experiments the product was thoroughly 

 mixed and incorporated in a blancmange or cornstarch pudding in 

 the way previously described. Eight experiments of three days' 

 duration were completed in which four normal subjects assisted. 

 The results of these tests are recorded in the following tables : 

 Data of digestion e.vperiments with chicken fat in a simple mixed diet. 





Weight. 



Water. 



Pro- 

 tein. 



Fat. 



Carbo- 

 hydrates. 



Ash. 



Experiment No. 274, subject E. F. B.: 



Grams. 

 2,357.0 



545.0 

 1,549.0 



192 



Grams. Grams. 



1,072 45.7 



49. 57. 8 



1, 346. 1 12. 4 



Grams. 



359.7 



8.2 



3.1 



Grams. 

 863.6 

 421.3 

 179. 7 



Grams. 

 16.0 



Wheat biscuit 



8.7 



Fruit 



7.7 



Susar 







192. 1 













Total food consumed 



4,643.0 

 148.0 



2,467.1 



115.9 

 44.4 

 71.5 



.371.0 



26.4 



344.6 



1,656.6 



65.0 



1,591.6 



32.4 



Feces 



12.2 







20.2 











Per cent utilized 





61.7 



92 9 



96.1 



62 3 











Experiment No. 275, subject D. G. G.: 



Blancmange containing chicken fat 



1,597.0- 726.3 

 396. 3.5. 7 



31.0 



42.0 



3.9 



243.7 

 5.9 

 1.0 



585.1 



306.1 



57.1 



158.0 



10.9 



Wheat biscuit 



6.3 



Fruit 1 



492 

 158.0 



427.5 



2.5 



Sugar 







i 





Total food consumed 



2,643.0 



88.0 



1,189.5 



76.9 



250.6 



1, 106. 3 



40.1 



1,066.2 



19.7 



Feces 



26.2 

 50.7 



15.6 

 235.0 



6.1 







13.6 













Per cent utilized 





65.9 03 8 



96.4 1 69.0 





1 





" 







1 U. S. Dept. Agr., OlTice Expt. Stas. Buls 126 (1903), pp. 18-20; 193 (1907), pp. 47-59; Connecticut Storrs 

 Sta. Rpt. 1890. pp. 178-180. 



2 Connecticut Storrs Sta. Rpt. 1905, pp. 135, 136. 



