Design, construction and testing of a motorised forage chopper

Abstract

The livestock sector in Uganda accounts for about 17 percent of agricultural value. In Uganda, majority of the small-scale farmers rely on the use of rudimentary tools mostly panga to cut forages for silage production. This is associated with drudgery, body injury, time wastage among others. The forage choppers used by farmers are manual while others are motorized but these are de-merited with a longer length of cut. That length doesn’t favor proper silage production and therefore the need to design an affordable and easy to-maintain forage chopper capable of producing a short length of cut. In this study, the main focus was to design, construct and test the performance of a forage chopper of capacity 381.549kg/hr. It was constructed from mild steel except the cutting blades that were made of stainless steel. The chopper consists of the hopper, frame, cutting blades and disk, cutting chamber, 2hp single phase ac motor, connected to the cutting blades in the chamber via a shaft and power transmission system. The shaft diameter was 25mm while it’s length was 340mm. The equipment was tested and evaluated using elephant grass and maize forages. The machine efficiency for cutting elephant grass good for silage making is 67.4%, that of maize is 61.3%. The throughput capacity and percent machine losses respectively is 381.549kg/hr and 32.6% for elephant grass and 284.437kg/hr and 38.7% for maize respectively. Silage is made from results suiting chop length. The considered losses /unacceptable portion can be fed directly to livestock animals. The average estimated cost chopper was 423.6 USD and it will facilitate animal feed availability during all seasons which will enhance livestock production especially cattle production.