20 CONTROL BULLETIN NO. 136 



Poultry Feeds with an Ash Content in Excess of 11 Percent 



For some time it has been the practice of the Control Service to determine the 

 acid insoluble ash in the mixed feeds containing over 1 1 percent ash. So far as 

 the Control Service is concerned an ash content of 11, 12 or 13 percent is, in 

 itself, not objectionable. The purpose of the acid insoluble ash determination 

 is to make sure that the high ash is not, in part, composed of sand or grit added 

 without being declared in the list of ingredients. 



The following table lists 24 feeds. It may be noted that the ash varies from 

 11.1 to 13.6 percent, and the acid insoluble ash from 0.4 to 3.7 percent. 



Four feeds of one manufacturer were found to have an acid insoluble ash 

 content of from 2.9 to 3.7 percent. This manufacturer was using, as one of the 

 ingredients, a defluorinated phosphate rock that contained about 50 percent 

 sand. To give an acid insoluble ash content of 3.7 percent, it may be calculated 

 that about 6 percent defluorinated phosphate rock was used, assuming 0.7 per- 

 cent acid insoluble ash as the maximum normal content of mixed feeds. This 

 means the addition of about 60 pounds of sand to every ton of feed. This manu- 

 facturer was informed that a declaration of the percentage of sand added would 

 be required if the use of such quantities of the defluorinated phosphate rock were 

 continued. A tentative maximum acid insoluble ash content of 1.2 percent was 

 set as being permissible without declaration of sand or grit content. The manu- 

 facturer agreed to use other sources of inorganic phosphorus to reduce the acid 

 insoluble ash content of the feeds in question. 



The other manufacturer whose feed was found to contain 2.4 percent acid 

 insoluble ash could not give a satisfactory explanation. He was informed also 

 that a declaration of sand content would be required if the particular feed con- 

 tinued to show a high acid insoluble content. 



Apparently it is possible for most feed manufacturers to market poultry mashes 

 with an acid insoluble ash content of less than 1.2 percent. A very few manu- 

 facturers will not be permitted to use ingredients that introduce 50 or 60 pounds 

 of sand into every ton of feed unless the labels are so marked that the purchaser 

 knows how much added sand there is in the feed he is buying. 



