Donkeys are becoming increasingly important for draught animal power
(DAP) in Zimbabwe and the sub-Saharan region. This is mainly because catde, 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. In an attempt to rectify this deficiency, a rapid rural appraisal (RRA) and
a series of studies were undertaken. The RRA was conducted first to assess the
status, role and current management practices of DAP in smallholder farming areas in
the semi-arid regions of Zimbabwe. Studies were carried out to assess; the
morphological characteristics of 335 working donkeys in south-western Zimbabwe,
the relations between live weight and body measurements and the seasonal
fluctuations of live weight and body condition of selected donkeys in semi-arid areas.
The other studies evaluated the draught performance of teams of donkeys and cattle
ploughing at different sites. Finally, the effects of drinking water and work on dry
matter intake (DMI) as well as apparent dry matter digestibility (DMD) and mean
retention time (MRT) of donkeys were investigated.
The results of the RRA showed that large numbers of cattle died (up to 75 per
cent in some areas) during the 1991-92 drought and that this had increased the
farmers' dependency on donkeys for DAP. However, the management of donkeys
was generally inadequate. For example, there was widespread use of the
inappropriate neck yokes and improper harnesses on donkeys in some of the areas.
The study on morphological characteristics indicated that the typical
"Zimbabwean" donkey weighed 142 ±1.4 kg, had a heart girth of 115 cm (range 93 -
140), a height at withers of 105 cm (range 91 - 120) and was normally light grey in
colour. Male and female donkeys were of similar weight and body dimensions. The
single best predictor of live weight was heart girth (r2 = 0.864) followed by umbilical
girth (r2 = 0.753). There were seasonal fluctuations in the live weights and body
condition of 38 monitored donkeys with weight losses more apparent late in the dry
When used for ploughing in the wet season, a team of 4 donkeys considered
"optimal" for ploughing and 2 oxen of similar total team weights exerted similar
draught forces, 867 N and 900 N (P>0.05); generated similar power outputs, 689 W
and 920 W (P>0.05); worked at similar speeds, 0.87 m/s and 1.03 m/s (P>0.05) and
had similar effective field capacities, 14.2 hours/ha and 14.5 hours/ha (P>0.05),
respectively. Lighter donkey teams generated less power output than heavier teams.
Over a 35-day period, individually penned donkeys that had access to water
every 48 hours (n = 6) and every 72 hours (n = 6) consumed less water (by 42 per
cent, P<0.001), 4.9 ± 0.30 litres/d and 5.1 ± 0.29 litres/d, respectively, compared with
8.5 ± 0.61 litres/d for donkeys with ad libitum access to water (n = 6). This was
accompanied by a reduction in DMI of 13 per cent (P<0.05). Donkeys with restricted
access to water lost less water through the faeces (by 9 per cent, P<0.05) than those
with ad libitum access. Donkey teams subjected to work (carting) had similar DMI to
those teams not working. The work did not have an effect on DMI, 3.3 kg DM/d for
working and non-working donkeys and neither did the time of access to feed
(P>0.05). DMD and the MRT of digesta were not affected (P>0.05) by work.
It was concluded that the shortage of cattle had increased the use of donkeys
for DAP in the semi-arid areas of Zimbabwe. Extension information on good
management practices and general welfare of draught animals, particularly donkeys,
was clearly lacking. The morphological characteristics of male and female donkeys
showed few differences and potentially the draught performances of the two sexes
could be similar. Donkeys in Zimbabwe were morphologically similar to their
counterparts in other parts of Africa implying that these donkey types are related.
Heart girth, the best single predictor should be included in predictive equations for
estimating live weight using body measurements. Weighbands and nomograms which
are important management tools for smallholder farmers should be produced from
these predictive equations. Although there were seasonal fluctuations in live weight
and body condition of donkeys, these were less than those reported in cattle. Thus,
donkeys are more likely to be in better condition at the start of the ploughing season
than cattle. Donkey teams were capable of ploughing for up to four hours per day
provided they had a sufficient combined team weight to pull the plough. Training and
experience are very important factors affecting the performance of working animals.
Donkeys were able to continue eating despite the limited access to water and this is an
important mechanism for survival during droughts. Working donkeys could not
increase DM intake of hay and this was attributed to the poor quality and physical
form of the hay. Supplementation of working donkeys might be necessary.
The importance of donkeys is likely to increase in the semi-arid areas where
the susceptibility of cattle to the recurrent droughts has been exposed.