Donkeys are becoming increasingly important for draught animal power (DAP) in Zimbabwe and the sub-Saharan region mainly because cattle, the traditional DAP source, have suffered high mortalities in recent droughts. However, there is limited information on the extent of use and potential of donkeys for DAP in Zimbabwe. To rectify the deficiency, two surveys and a series of studies were undertaken. In the first survey, a rapid rural appraisal (RRA) was undertaken to assess the status, role and management practices of DAP in smallholder farming areas in the semi-arid regions of Zimbabwe. The second survey assessed the morphological attributes of 335 working donkeys, the relationships between live weight and body measurements and the effect of seasonal fluctuations of herbage availability on live weight and body condition of the donkeys. This was followed by experiments to measure the draught performance at ploughing and to investigate the effects of water and work on dry matter intake (DMI) by donkeys. The results of the RRA showed that large numbers of cattle died during the 1991-92 drought (up to 75 per cent in some areas) and that this had increased the farmers' dependency on donkeys for DAP. The management of donkeys was generally inadequate. For example, there was widespread use of the inappropriate neck yokes on donkeys in some of the areas. The survey on morphological attributes indicated that the typical "Zimbabwean" donkey weighed 142 kg, had a heart girth of 115 cm, a withers height of 105 cm and was normally light grey in colour. Male and female donkeys were similar in size. The single best predictor of live weight was heart girth (r<SUP>2</SUP> = 0.864) followed by umbilical girth (r<SUP>2</SUP> = 0.753). Donkeys lost weight and body condition during the late dry season. When used for ploughing in the wet season, donkey and cattle teams of similar total team weights exerted a similar draught force (863 N (±49.6) and 912 N (±98.2), P>0.05), generated similar power output (743 W (±68.8) and 938 W (± 140), P>0.05), worked at similar speeds (862 m/s (±69.5) and 1012 m/s (±64.3), P>0.05) and had similar effective field capacities (14.9 hours/ha (± 1.30) and 13.6 hours/ha (± 1.46), P>0.05), respectively.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:659930 |
| Date | January 1998 |
| Creators | Nengomasha, Edward Musiwa |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/30568 |
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