376 POULTRY PRODUCTION 



all rations and is the most expensive. This classification 

 holds only to a limited extent on the market. The feeds 

 containing the most digestible protein are ordinarily com- 

 paratively high in price, l)nt the prices are not always in 

 exact proportion to the protein content. Therefore protein 

 may be cheaper from one source than from another. 



It frequently becomes advisable in practice to vary the 

 nutritive ratio of a ration in order to use larger amounts of 

 a cheaj) feed. While this may be done without serious results, 

 care should be taken that too great a deviation is not made 

 from the accepted ratio, and a return to the correct ratio 

 should be made as soon as the prices of feeds will permit. 



The feed cost of a dozen eggs with feed at varying prices 

 is shown in Table XLII, page 37-5. This table was calculated 

 from the data of Kirkpatrick and Card' and of App, A\'aller 

 and Lewis'^ (see page 380) . 



' Sloirs Bullcliii, Xo. 82. 



' Xrw Jfrii-,\ I'.ulletin. Xo. .'>29. 



