It appears from these figures that the farmer who purchases straight by-products 

 and depends upon the attached guarantees as a statement of their composition would 

 be sure of their being correct 9.5 times in 100. If he purchases prepared feeds he 

 could be assured of their composition by depending upon the guarantee 93 times in 

 100. While it is quite evident that in some cases more care should be exercised in 

 making sure that the various materials meet their guarantees, the record on the 

 whole must be regarded as moderately satisfactory. Some variations from guarantee 

 are bound to occur in by-products and mixtures of the same, in spite of all that can 

 be done to avoid them. 



Microscopic Examination of FeedingstuflEs. 



Chemical methods are used t6 determine the protein, fat and fiber that a feeding- 

 stuff contains. The microscope supplements the work of the chemist in that it shows 

 the material from which the feedingstuff is made. Certain peculiar characteristics of 

 the tiny starch grain, the cell or the fiber of a plant or grain serve to identify the 

 material to the skilled microscopist as readily as larger pieces can be identified by the 

 unaided eye. 



The microscopic examination is made primarily to determ.ine if all the ingredients 

 are present as guaranteed and to see that nothing has been added in the nature of an 

 adulterant. A somewhat deeper significance lies in the fact that while a feedingstuff 

 may meet its guarantee in protein, fat and fiber, the value of the chemical constituents 

 may vary mdely when derived from different sources. It has been demonstrated that 

 proteins derived from one plant are not always perfectly balanced and that best 

 results are obtained when proteins from several sources are found in a ration. It is 

 also true that fiber varies widely in degree of digestibility; for example, the fiber from 

 the corn kernel is softer and much more digestible than the fiber from the oat hull. 



The microscopist at the present time is usually able to tell the kind, but not the 

 quantity of an ingredient present. When both the chemical analysis and microscopic 

 report are at hancl it is, however, often possible to judge whether a certain ingredient 

 is present in large or small amounts. It is not unreasonable to expect that under 

 further development of our knowledge of feedingstuffs both from a chemical and 

 microscopic standpoint it will be possible to determine the ingredients of a mixed 

 feedingstuff within reasonable limits. Such knowledge would be invaluable to feed- 

 ingstuff inspection. 



During the year 260 samples selected from proprietary feeds were examined by 

 Frederick A. McLaughlin. The feeds were with few exceptions as guaranteed. The 

 examination showed that in some instances manufacturers have changed the in- 

 gredients in the formula as registered without filing notice of such change. In no 

 instance where this occurred could deliberate adulteration be charged and the guarantee 

 tag corresponded with the conteats of the sack rather than with the registration. 

 Attention is again called to the fact that a feed offered for sale should correspond in 

 every particular with its registration and that changes in the formula are allowed 

 which do not lower its feeding value if information be properly filed and the necessary 

 changes made in the guarantee tag. 



The following feeds were found which did not conform to guarantee: 



Diehl's Dry Mash. Contained in addition to ingredients stated, charcoal and whole 



com. 

 Climax Cream Mash (J. W. Day & Co.). Contained oats and oat hulls in addition 



to ingredients guaranteed. 

 Emerson's Gem Mash. In addition to ingredients declared, contained a considerable 



amount of low grade material, probably screenings or sweepings. 



