should be pointed out that the chemical analysis of a particular lot of an 

 ingredient may be somewhat above or below the average figure shown in 

 the table. This fact must be taken into consideration in fixing guarantees. 

 The following example shows how the protein content of a feed mixture 

 may be calculated. 



The mixture contains 



225 

 1410 



X 100 = 15.95% Protein. 



The percentage of fat or fiber may be calculated in a like manner by sub- 

 stituting the fat or fiber figures for those of the protein. 



CONFORMITY TO GUARANTEES 



The chemical analyses reported in this bulletin were made by methods 

 approved by the Association of Official Agricultural Chemists. 



A total of 702 samples were submitted for analysis. Seventy-one brands 

 were sampled two or more times. Table I shows the percentage of samples 

 analyzed each year since 1926 that did not conform to guarantee. The total 

 percentage of samples failing to conform to the guarantee is 7.8% deficient 

 in protein, 8.5% deficient in fat, and 4.0% carried an excess of fiber. In all 

 except very rare cases, the deficiencies were quite small. 



Table II lists the analyses of the official samples of ingredients and 

 mixed feeds. Table III lists the analyses of the official samples of dog and 

 cat foods. Both the dry and canned foods are included in this table. 



Bold face type and underline of the figure is used to indicate a de- 

 ficiency of more than 0.5 per cent below guarantee in protein, of more than 

 0.25 per cent below guarantee in fat and an excess of more than 1.00 per 

 cent above the guarantee in crude fiber. 



Eighteen brands of the cat and dog foods were not registered at the 

 time of sampling. Sixty-six brands of the mixed feeds or ingredients were 

 not registered at the time of sampling. They are identified in the tables 

 showing the analyses. 



Forty-three of the official samples were drawn from "bulk" lots of 

 feed. They are identified in table II. 



The samples containing sulfaquinoxaline and/or nicarbazin were 

 analyzed for the drug content. No serious deficiencies were found. 



It is expected that more work will be done in the determination of the 

 drug content of medicated feeds in the future. 



