Influence of grinding method and grinding intensity of corn on mill energy consumption and pellet quality/Uticaj nacina i intenziteta mlevenja kukuruza na potrosnju energije mlina i kvalitet dobijenih peleta

In recent years there is an emerging trend of coarse grinding of cereals in production of poultry feed due to positive influence of coarse particles on poultry digestive system. Influence of grinding method (hammer mill vs. roller mill) and grinding intensity of corn (coarseness of grinding) on mill specific energy consumption and pellet quality was investigated. By decreasing grinding intensity of corn (coarser grinding), specific energy consumption of both hammer mill and roller mill was significantly decreased (p < 0.05). When comparing similar grinding intensities on hammer mill and roller mill (similar geometric mean diameter or similar particle size distribution), specific energy consumption was higher for the hammer mill. Pellet quality decreased with coarser grinding on hammer mill but, however, this effect was not observed for the roller mill. Generally, pellet quality was better when roller mill was used. It can be concluded that significant energy savings could be achieved by coarser grinding of corn before pelleting and by using roller mill instead of hammer mill. From the aspect of pellet quality, if coarser grinding is applied it is better to use roller mill, concerning that more uniform particle size distribution of corn ground on roller mill probably results in more uniform particle size distribution in pellets and this provides better pellet quality. Keywords: grinding, energy consumption, pellet quality, poultry, corn Kod uzgoja zivine se uglavnom primenjuje peletirana hrana, a prvi korak u proizvodnji peletirane hrane je mlevenje pojedinacnih sastojaka smese. Za mlevenje su najvise u upotrebi mlinovi cekicari dok su mlinovi na valjke znatno manje zastupljeni. Iako je dugo smatrano da je sitno mlevenje kljucno za proizvodnju kvalitetnih peleta i dobro iskoriscenje hrane u probavnom sistemu zivotinja, krupnije mlevenje zitarica, kao osnovnih komponenata hrane za zivinu, postaje sve zastupljenije. Razlog za ovo je sto mnoga istrazivanja ukazuju da krupnije mlevenje ne dovodi do znacajnijeg narusavanja kvaliteta proizvedenih peleta kao i da prisustvo krupnih cestica pozitivno deluje na probavni sistem zivine. Cilj ovog istrazivanja bio je da se ispita uticaj nacina mlevenja (mlin cekicar ili mlin na valjke, tj. siroka ili uska raspodela velicine cestica) i intenziteta usit njavanja kukuruza na specificnu potrosnju energije mlina i kvalitet dobijenih peleta. Sa smanjivanjem intenz iteta usitnjavanja (krupnije mlevenje), doslo je do znacajnog