International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 11| Nov 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 547
Design and performance evaluation of a NARO forage chopper
prototype for smallholder dairying systems
Kiggundu Muhammad
1
, Kato Hussein Walusimbi
2
, Komakech Jimmy
3
, Mugerwa Swidiq
4
1,2,3,4
National Agricultural Research Organization-National Livestock Resources Research Institute, P. O. Box 5704,
Kampala, Uganda
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Abstract - Feeding dairy cattle un-chopped forages is
associated with selective feed consumption and high feed
wastage. Although majority of farmers still rely on the use of
rudimentary implements notably the panga for chopping
forage, use of such implements is time consuming and is
associated with drudgery and health hazards. In this article,
we describe the process of designing, fabrication and
evaluation of a low-cost forage chopper used to chop forages
to reduce drudgery associated with the use of rudimentary
chopping implements. The forage chopper prototype consists
of a 7.0 horse power water cooled diesel engine, connected to
cutting blades in a cutting chamber via a shaft and coupling
joint. We tested and evaluated the chopper prototype using
different forages. Averagely, the machine was capable
chopping 859.3 kilograms per hour. The average length of the
chopped materials was 2.9 cm and 2.1 cm for Napier grass and
maize, respectively. The average estimated cost of the chopper
was 882.6 USD compared with average cost (1,184.2 USD) of
imported choppers with diesel engines of similar horsepower,
implying that farmer could save up to 301.6 USD at the time of
purchasing the chopper.
Key Words: Forage chopper, performance evaluation,
smallholder dairy, Uganda
1. INTRODUCTION
Napier grass (Pennisetum purpureum) constitute the
dominant forage-based feed resource fed to dairy cattle
under zero-grazing systems in East Africa (Lukuyu et al.,
2012). The forage is normally offered to dairy cattle in un-
chopped or inappropriately chopped form (Kiyimba, 2011)
leading to significant feed wastage attributed partly to
selection of palatable and/or refusal of unpalatable fodder
parts by animals (Zemmelink and Mannetje, 2002). Yet,
appropriate chopping of fodder has been demonstrated to
boost feed intake, lower feed rejection and consequently
reduce feed wastage by 50 percent. In an attempt to boost
feed utilization efficiency in forage-based dairy feeding
systems through minimization of feed wastage, farmers use
several farm implements notably pangas (Photo 1), manual
chaff cutters and motorized forage choppers to chop
different forage resources. However, the many forage
chopping equipment particularly pangas and chaff cutters
are associated with several limitations including drudgery,
ineffectiveness, and health concerns. Indeed, several farmers
have reported loss of fingers during panga-aided forage
chopping operations.
Photo-1: Farmer chopping Napier grass using a panga
Also, majority of the forage choppers used in Uganda are
imported into the country but the high initial cost of
purchase (average USD 1,184.2) coupled with the shortage
of after-sales repair and maintenance services discourages
farmers from buying the imported machines. In addition,
some of the choppers are made from low quality and/or light
metal sheets reducing the productive life of the machines.
Therefore, in this article we describe the design,
development process and performance of a low-cost and
effective forage chopper prototype that can be used and
operated by smallholder dairy farmers to appropriately and
efficiently chop forage resources, boost feed intake, reduce
wastage and consequently bolster productivity of small-scale
dairying systems.