Effect of preconditioning and die thickness on pelleting of livestock feed

Abstract

Pelleting has been identified as a means of improving animal performance by limiting selective feeding of livestock. However, it is a complex process that has a number of input variables that must be routinely monitored and adjusted. The interaction between the operational parameters may also give more knowledge of the process. In this study, a screw-type livestock feed pelleting machine was designed and fabricated having a maximum throughput of 0.43 kg/min. Using a full factorial design with three levels of die thickness (5, 7 and 9 mm) and two preconditioners (water and cassava starch), average density of pellets produced was greater than 1g/cm3 For the determination of the density and pellet length, and consequently the durability, the die thickness, plasticiser and interaction of die thickness with plasticiser were significant (p < 0.05). Using starch as preconditioner and increasing the die thickness improved the durability of pellets.