16 CONTROL BULLETIN No. 113 



MANGANESE IN COMMERCIAL POULTRY AND CHICK RATIONS 

 H. Robert DeRose 



It has become a general practice to add manganese to commercial mashes as a 

 preventive of perosis (bone trouble) in growing chicks and to improve shell 

 texture and maintain weight in adult birds. A normal ration that does not have 

 an excess of corn will usually contain between 40 and 50 parts per million of 

 manganese. It is not within the province of regulatory officials to fix the levels 

 at which manganese should be present in a ration. This is a function of the poul- 

 try nutritionist, and even among experts there appears to be some disagreement 

 a? to levels below which the manganese content should not fall. Rather, it is the 

 duty of control officials to present analytical data as found; the interpretation 

 and application of such data to lie with the poultryman and nutritionist. 



Over three hundred samples of commercial mashes were tested for manganese 

 content. In most of them added manganese was declared. However, there seemed 

 to be no uniformity of declaration. In some instances where manganese was 

 declared, it does not seem possible that the quantity found was any greater than 

 should have been present in the natural ingredients used. In other instances 

 where a declaration of added manganese was lacking, it does not seem possible 

 that the amount found could have been obtained from natural ingredients. 



The extremely small amount used must present mixing problem? which can be 

 partially obviated by first mixing the manganese with calcium carbonate or 

 oyster shell meal before introducing it into the feed mixture. 



Of the several manganese salts used, anhydrous manganese sulfate predom- 

 inated, although the carbonate and dioxide were also used in a few cases. The 

 relative merits of these several salts is not known. Where a declaration of quan- 

 titative content is made, it should be in terms of the element alone and not as the 

 sulfate or other salt used. The intent of the manufacturer on this point is not 

 always clear. 



Especial reference is made to an article entitled "Studies in Mineral Nutrition 

 of Laying Hens. I. The Manganese Requirement," by Gutowska and Park- 

 hurst, found in Poultry Science XXI, No. 3, Mav 1942. 



