INSPECTION OF COMMERCIAL FEEDSTUFFS 



By Feed Control Service Staff : 



John W. Kuzmeski, Research Processor, Official Chemist 



Albert F. Spelman, Associate Research Professor 



C. Tyson Smith, Assistant Research Professor, Microscopist 



Robert T. Wefherbee, Assistant Research Professor 



Joseph Bart, Research Instructor 



Joseph A. Martell, Technical Assistant 



Edward S. Berestka, Technical Assistant 



Joseph Conklin, Inspector 



Cora B. Grover, Principal Clerk 



Foreword 



Until a comparatively few years ago the inspection and analysis of feeds was 

 a relatively simple matter. The manufacturer guaranteed protein, fat, fiber 

 and carbohydrate or nitrogen-free extract. The list of ingredients, although 

 containing a rather wide variety of materials, did not remind the reader of a 

 page in the U. S. Pharmacopoeia. The control official had no particular difficulty 

 in either substantiating or refuting the manufacturer's claims. 



An examination of this bulletin will show how much times have changed. 

 In it are reported the results of tests for protein, fat, fiber, ash, calcium, cobalt, 

 copper, iodine, iron, magnesium, manganese, nickel, phosphorus, salt, zinc, 

 vitamin A, vitamin D, carotene, choline, riboflavin, nitrophenide, nitrosal, and 

 sulfaquinoxaline. 



The tests enumerated still do not cover all of the claims made. For example, 

 at present this Control Service is not checking on the claims for such dietary 

 factors as vitamin B12. the antibiotics rom the various sou ces, niacin and 

 pantothenic acid. 



Although the appearance of new drugs and dietary factors in feeds has presented 

 the control official with analytical problems, the manufacturer has encountered 

 much greater problems involving the handling, mixing, and keeping quahties of 

 these materials. Unless the manufacturer of mixed feeds buys accurately pre- 

 mixed supplements or concentrates the proper blending o ihe minerals, vitamins 

 and drugs with the usual feed ingredients to insure uniform distribution through- 

 out the feed mixture requires not only costly equipment but also the technical 

 "know-how" to operate efficiently such equipment. 



The manufacturer's concern does not end with the knowledge that the feed 

 has been properly mixed. Some of the ingredients used would deteriorate com- 

 paratively quickly during storage if precautions were not taken to prevent this. 

 By the use of anti-oxidants and other means the manufacturer prolongs the keep- 

 ing qualities of the less stable ingredients so that the mixed feed, even after a 

 reasonable period of storage, still contains all factors in amounts adequate to 

 accomplish its intended purpose. The fact that so few guarantees are found 

 seriously out of line is a tribute to the ability and resourcefulness of those engaged 

 in the production of feeds. 



