No C. DKFAUTMENT OK A(;illCl'l/riJRI<:. 897 



CAI.CULAT10N OP THE COMPOSITION OF 



MIXED FEKDS. 



Bv Dit. \VM. FUEAIi, Chemist of the Pcnna. Slate Agr. ErjA. Slalimi. 



The reeeut act regulating the manufacture of inl.ted and concen- 

 1 rated cattle foods in Pennsylvania re(iuires, that to each ])ackage, 

 or lot of the foods, included under the provisions of the act, shall 

 he attached a brand and a guaranty of the percentage of protein 

 and fat the goods contain. Many iu(iuiries have been received from 

 manufacturers and dealers for information enabling them to comply 

 with the guaranty requirement. 



Where the quantities of the goods sold permit their manufacture 

 in large quantities, so that considerable values are involved, the 

 guaranty should be based upon an analysis of a carefully drawn, 

 representative sample of each lot manufactured; or upon calculations 

 from the quantities and composition of tlje ingredients" used; the 

 latter being either ])urchased u])on guaranty or themselves sep- 

 arately analyzed. 



2 he State has mide no iwovUlon for the aiialysls^ at puhlic co.st, 

 of manufacturer^^ samples. 



A word of caution to those desiring to send samples of feed-stujfs 

 to a chemi-it for analysis: It is just as important in the determination 

 of the composition of a material as a basis for its sale under guar- 

 anty, that the sample shall be thoroughly representative, as that the 

 analysis shall be made accurately. Perfect mixing of feed-stulTs 

 is dillicult, especially if fine, dense ])articles be mixed with coarse. 

 light materials, such as oat hulls, bran, etc. A handful of the mix 

 ture taken at random from the top of a heap or bin is 

 not at all likely to represent the average composition of the entire 

 nmss. To secure such a sample, portions must be drawn from differ- 

 ent i»artis of the hea]> or bin, especia.ly from the bottom and inter- 

 ior as well as from the top aud exterior; the several portions so 



•Note. In this circular the term "Ingredient" refers to the Individual feeding Btuffs thai are 

 used In making a mixture, oats, middlings, corn chop or rye bran, for example; the term 

 "constituent" refers, on the other hand, to the several groups of chemical substances of which 

 plant materials, and each Ingredient as such, are composed as protein, fat, fiber, ash, etc. 



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