V. ESTIMATION 405 



The ration is probably deficient in vitamin E. However, the storage of 

 this vitamin in chicks from hens fed practical diets is sufficient to carry 

 the chicks over the short period required for a vitamin K assay. Addition 

 of vitamin E to the ration is not advisable, since some of the oxidation 

 products of vitamin E that may be formed possess antihemorrhagic activity. 



A diet has been proposed in which the grain portion is heated for 1 week 

 at 120°. ^"^ Chicks grow very poorly on such a diet, and it is doubtful if it 

 possesses any real advantage over the one described above. Multiple de- 

 ficiencies should be avoided in biological assays. Another proposed diet^^ 

 is extremely deficient in calcium for the chick, and it is difficult to under- 

 stand how chicks could survive and grow on the diet as des(;ribed. 



TABLE I 

 Basal Ration for Chick Vitamin K Assay 



Ingredient Per cent 



Sardine meal, ether extracted 17.5 



Dried brewer's yeast, ether extracted 7.5 



Ground polished rice 72.5 



Cod liver oil 1-0 



Calcium carbonate 0.5 



Salt, common (contains 0.5% Mn in form of the sulfate or carbonate) 1 .0 



3. Administration of Supplements 



Considerable influence on potency by the carrier of the vitamin supple- 

 ment has been reported. Dann^- found 2-methyl-l ,4-naphthociuinone to be 

 three times as potent when given orally in oil as compared to water, whereas 

 Ansbacher et aU^ reported the quinone to be twice as potent in water as in 

 oil. Almc^uist and Klose''* obtained the same potency for the quinone in 

 water and ethyl laurate solutions. Vitamin Ki manifested different po- 

 tencies in reference to 2-methyl-l ,4-naphthoquinone, depending upon the 

 volume of oil carrier in a very short (6-hour) assay. '^ Whatever solvent is 

 chosen, it should be the same and in the same volume per dose for the as- 

 sayed substances as for the standard employed, so far as possible. 



Methods for parenteral administration have also been used. Phthiocol 



i« S. Ansbacher, Proc. Soc. Exptl. Biol. Med. 44, 248 (1940). 



" A. J. Quick and M. Stefanini, J. Biol. Chem. 175, 945 (1948). 



'2 F. P. Dann, Proc. Soc. Exptl. Biol. Med. 42, 663 (1939). 



" S. Ansbacher, E. Fernholz, and M. A. Dolliver, J. Am. Chetti. Soc. 62, 155 (1940); 



Proc. Soc. Exptl. Biol. Med. 43, 652 (1940). 

 1^ 11. J. Almquist and A. A. Klose, Proc. Soc. Exptl. Biol. Med. 45, 55 (1940). 

 '^ S. A. Thayer, R. W. McKee, S. B. Binkley, and E. A. Doisy, Proc. Soc. Exptl. 



Biol. Med. ^i, 5S5 (1940). 



