Inquiries occasionally are made regarding a method of calculating 

 the protein, fat, or fiber content of a home-mixed feed. There are tables 

 available, such as those in Morrison's book "Feeds and Feeding," which 

 give the average chemical analysis of feed concentrates, roughage and 

 silages. It should be pointed out that the chemical analysis of a par- 

 ticular lot of an ingredient may be somewhat above or below the aver- 

 age 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 

 substituting 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 official samples were submitted for analysis. Seventy 

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

 of samples analyzed each year since 1926 that did not conform to guar- 

 antee. Table II lists the analyses of official samples of feed ingredients 

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

 and canned cat and/or dog foods. Of 639 ingredients and mixed feed 

 samples, 3% were 0.5% or less deficient in protein and 4.1% were de- 

 ficient over 0.5% in protein; 1.1% were deficient 0.25% in fat and 

 3.8% were deficient more than 0.25% in fat; 4.1% exceeded the guar- 

 antee in crude fiber. Of 63 cat and, or, dog foods 9.5% were 0.5% or 

 less deficient in protein, 12.7% were deficient more than 0.5 't in pro- 

 tein. Only 0.3 % showed deficiencies in fat and none contained excessive 

 crude fiber. Percentage figures based on the total number of samples 

 are shown in Table I. 



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. 



Seventy-four samples of mixed feed or ingredients were not regis- 

 tered at the time of sampling. 



Twenty samples of cat and/or dog foods were not registered at time 

 of sampling. They are so indentified in Table II and III. 



