INSPECTION OF COMMERCIAL FEEDSTUFFS 



By Feed Control Service Staff 



Jolin W. Ku/mcski. Research Professor, Official Chemist 



Albert F. Spelman, Associate Research Professor 



C. 1 yson Smith, Associate Research Professor, Microscopis 



Bertram Gerslen. Assistam Research Professor 



David F. Owen, Jr., Research luslriicior 



Shirley J. Richards. Research Instructor 



Joseph Conklin, hispecior 



Edward F. Vlach, Technical Assistant 



Paul Korpila, Laboratory Assistant 



Cora B. Cirover, Principal Clerk 



INTRODUCTION 



In this bulletin, among other results, are analytical data concerning the drug 

 md vitamin content of various products. Some of these data show that the products 

 contain slightly lower than guaranteed amounts of drugs or vitamins. 



Most of the drug and some of the vitamin assay methods used to obtain the 

 listed results are relatively new. These methods do not yield results as precise as 

 those obtained by methods for the determination of some of the inorganic elements, 

 for example. 



Therefore, if the listed drug or vitamin results are within 10 percent of the 

 guaranteed amounts it may be considered that the drugs or vitamins are present in 

 substantially the amounts guaranteed. 



The drugs or vitamins found in amounts seriously below those guaranteed 

 are indicated either by asterisks or numbers with explanations in the footnotes. 



