195 
l95-,ay Distr. LIMITED
ECA/NRD/E/8 5 January 1 Original: E
ECONOMIC COMMISSION FOR AFRICA
Regional Preparatory Meeting on New
and Renewable Sources of Energy Addis Ababa (Ethiopia) 12-16 January 1981
ANIMAL_POWER IN AGRICULTURAL
PRODUCTION SYSTEMS
(integrally reproduced from "Animal Review 11 n. 
19^0)
F.M. INNS
Professor       of       Agricul Engineering
University     of     Dar     es May 1979
The    views    and    suggestions    contained    in    this    document    are    those    of    the    author    ai not necessarily reflect those of the Economic Commission for Africa.Animal power 
in  agricultural  production Systenms 
with special referenoe to Tanzania 
F.M. Inns 
The  input  of  mechanical  energy  un der  the  control  of  man  is  a  funda mental  feature  of all  agricultural  sys tens.  It  distinguishes  agricultural production from the "hunting and  col lecting"  subsistence  economy,  which is  practised  by  only  very  few  people in  the  world  today. 
Machinery   is   the   means  by   which mechanical  energy  is   transmitted,   un der  control,  so  as  to  perform  a desired operation  contributing  to  agricultural production.      This   is    the   basis   of 
mechanized 
simply  in  Figure  1.  The  diagram emphasizes  the  two  essential  compo nents  of  mechanizcd  farming,  me chanical  energy  and  machinery. 
Mechanical   cnergy   is    used    when lorces  are  applied  to   an  object  lo  do 
Work.         Most   commonly   in    agricul The    author   is    Professor   of    Agricultural          Dar-cs Engincering   at    the    University   of 
farming.   illustrated   very 
AI  an 
oxen  are  Irained 
agricultural training  centre,  Upper  Volta,  where,  assisted  by  an   FAOjUNDP  project, 
for land cultivation    -  a  lchique previously  nknown  in   Upper  Volta 
Salaam, 
Tanzunia. 
PO    Box    35091, 
This  article  is    bascd  on   a  paper 
Dar-es-Salaam, 
presenled  to 
Tanzanian   Socicty   of 
the  Six1h  Scientific  Conference, 
Iringa,       by        held 
tion Courlesy  of  the Agricultural 
in   May 
1979.     It   is 
Animal   Production,             published 
Group  of 
FAO. 
Agricullural   Serviccs 
Mechaniza 
Sion, 
Divi 
2 
Bullocks  drawing  cultivator for  preparat.on of  seedbed  for  millet  production  in  Niger 3 
sup provide 
farm.     smallholder 
would 
tractor 
one      about 
S0-kW 
i.e., 
correlation 
available        sta 
established   a 
analysed 
(1975) 
and 
tistics 
Giles 
some 
ex an  covering      of 
matter      of 
a is It area. tensive 
land,   A supplemen 
of ha 
4 to about   3 
for   tation 
work 
0.3 
about     supplementation       by 
of pair 
such provide 
involve 
operations             that 
the 
field 
and mobility 
for 
tial 
necessary.       A 
would 
kW/ha    is 
Oxen 
DEVELOPMENT AGRICULTURAL 
AND 
PowER 
essen 
This      is 
supply. 
fuel portable 
then 
providers 
hence   concentrated          and 
the 
of  input 
power? 
animal 
power engine 
only heat 
have   a 
arc These 
that 
level desirable 
use 
Why 
Typically 
power hall 
0.4 
kW/ha.  If 
providing  a 
a taken  as 
0.1  about 
kW/ha    is 
dicsel). 
land, 
hectare    of 
(petrol  or 
human,          an 
operations:    a 
and     a animal 
field 
for 
about 
one 
Africa 
a in 
available 
sources 
power 
practical 
three 
For 
only 
approxiniately 
to 
(corresponding                      crop 
ton/ha). 
works 
adult 
2.5   about 
level      of 
kW/ha 
output     of 
0.4 
agricultural animals         a as 
for 
are    there purposes 
plement. 
all 
power 
of use 
power increasing 
for 
yield 
a to up   inputs 
crease        of 
the 
operations. Source       ot 
concerned  with 
supply. 
article       is 
This fucl 
the 
in  of rate 
This 
oxidization      of 
chemical 
plough      or animal     or 
pulling    a 
in  as 
digging.       or 
hectare agricultural 
Figure     2. 
per 
high 
shown  in 
power 
indicates   a as  yield, 
available 
crop 
between 
and 
basic 
same 
thc 
process activated      by 
viders    is 
im other 
such traclor. continuous               when example,      in intermittent              when 
for 
man, 
provided             an by 
hoeing       or provided          by 
pro   power 
these 
each      of 
that interest 
are    forces 
the 
ture 
power 
between relationship 
outptts         in 
crop production   and        inpuus Figure 2 
The 
ration 
ope farming mechanized 
diagram       a of Fundamental 
1975)       GILES,     (SoURCE: 
hectare 
(kW/ha) 
per     Power 
0. 
OUTPUT 
harvesting 
operation agricultural 
planting. 
tillage, 
e.g.. 
Aggregale 
(lor/ha) yield 
An machine 
implement     or 
Tool, 
Figure   1 INPUT 
energy  Mechanical 
major 
crops 
veterinarian  in 
of 
for 
Table 2 
Soe 
Egypt 
oxen 
Mennon       in 
colossi       of 
the 
front      of 
Moderate somctimes 
effective 
for 
High 
Use 
WFP) 
with 
(PiloTO: 
land   irrigated 
newly Ploughing 
farmer   Sympathetic 
and 
artisaDS 
Skilled 
calculations. requircd requiremcnt 
Spudung     as 
Self 
a 
foreign        CXchange             cost                                High 
Management                  level Maintcnance 
Miscellaneous  Replacement 
5 
24 
3 
6 
(m/s) 
work kVh 
(h) 
field 
day 
for     spccd Maximum 
capability  (kN)  Maximum  pull 
per 
work Polential 
Work 
0.40 
5.95 0.40 5.95 
1.60 
3.30 
80.00 
165.00 
000.00 
per 
cxchange             cost 
Foreign 
use 
of  hour 
per 
cxchange           cost 
kWh 
Foreign 
per 
Cost 
S00 
(bascd         on 
use 
usagc) hours/ycar 
125 
of  hour 
per 
cost 
Total 
000.00 
kW) 
oKen oxen 
4 (1 
of  Pair 
Tractor 
kW) 
(50 
cost  Initial Costs 
Featute 
of pair 
a  and tractor characteristics        a of 
Comparison      of 
(TSh) 
TABLE  1. TABLE  2.    Cost  calculation  for  a  50-kW  tractor  and  a  pair  of  oxen 
Item 
Power  (kW) 
Initial  cost  (TSh) 
Economic  length  of service  (ycars) Salvage value  (%  of  iniial cost) Salvage  value  (TSh) 
Calculation of fxcd cost pcr annum (TSh) 
Tractor 
50 
125 000 
20 
25 000 
Pair  of  oxen 
4 000 
3 200 
Depreciation 
Interest  at 6% 
Insurance  al  3%  initial  cost 
Housing 
Maintenance  fecd:  3.2  fecd   units   per  day  at  TSh  0.20/ feed   unit 
20 000 
4 500 
3 750 
1 000 
Management:  125  man-hours/year at  TSh  2/man-hour Veterinary  care 
Drivers'  wages 
Annual  cost  per  kW 
TOTAL FIXED  COST/YEAR 
Approx.  foreign  exchange  cost  per  kW  per  year Calculation of hourly running cost at  S00  Jhourslyear (TSh) 
7200 
36 450 
729 
400 
160 
216 
120 
160 
468 
250 
400 
1774 
1 174 
200 
Spares  and   repairs 
Supplementary  work  fecd 
0.4 
Fuel:  6  l at  TSh  2.50/litre 
Drawing   water  from  a  well  in  India 
Oil:   10%   of   fuel   cost 
Operator's  wages 
TOTAL HOURLY  RUNNING COST 
Hourly  running  cost/kW 
Approx.  foreign exchange  cost/kWh 
2.0 
2.4 
-mentation  on  about  150  to  200  ha 
about  30  to  60  smallholder  farms. 
75 
15 
15 
915 
1.8 
0.8 
Total cost  per  kWih  of  work  (TSh) 
ANIMALS   OR    TRACTORS? 
Fixed costs 
Running  cost 
3.6 
managerial  problems  of  using  one 
2.4 
tor  in   activities   on   40 
ms  are  difficult  to 
overcome.  Many 
or  more 
TOTAL 
6.0 
thods        achieving of 
0.4 
agricultural  machinery""  have  been 
"multifarm  use 
57), 
posed     and     tricd     (Lonnemark, 
uped   and 
including    hirc    schemes    and 
Approx.  foreign  exchange  componenl 
Summary 
Cost per hour 
S0-kW   tractor 
Pair  oxen 
I  littlc 
Sents morc
a 
care  of   a 
success  to   datc.  Ownership 
co-opcrative   farms,   but 
work  animals 
Appro.r.  foreign  exchange  cost per  hour of use 
feasible 
been                               solution,  and proved   to   be   practicable 
pair  of 
50-kW. tractor 
Pair  oxen 
ny    countries   where 
Omc    of    the 
Ical                        characteristics 
of   a 
tractor    and    of 
ught   unit   (in   this   case an a   aninmal pair  ol 
n), he arc high comparcd  in  Table  L. 
cost   of    tractor   use,   at 165   (US^  20)  per  hour,  may   sur 
low. 
power   inputs 
Cost  per  kWh 
50-kW   traclor 
Pair  oxen 
Approx.  joreign exchange  cost per &Wh 
50-kW  tractor 
Pair  oXen 
1.5 
1.8 
3.3 
1.6 
(TSh) 
165 
6.0 
80 
0.4 
3.3 
6.0 
1.6 
0.4 
Cost  of   medicines. 
Source:  Have  and  Dihenga  (1979). prise  many  but  its  detailcd  costing  is 
given  in  Tuble  2.  This  compares  with 
a cost  of  TSh  6 (US$  0.72)  pcr  hour 
for  a pir of  draught  oxen.  The cost 
per  unit  of  cncrgy  (kWNh)  supplicd 
shows  the  tractor  in  a  morc  favour 
able  light,  being  little  morc  than  half 
thc  cost  per  unit  of  cnergy  from  a 
puir  of  oxcn.  Howcver,  two  points 
should  be  bornc  in  mind.  First,  the 
foreign  cx changc cost  per unit of trac 
tor encrgy  is  four  times that for oxen. 
Turning a water whccl for irrigution in lndia 
CEEMAT  (Centre  d'étude  et  d'expé rimentalion  du  mécanisme  agricole tropical)  and  based  on  African  ex periencc  (mainly  in  West  and  Central Africa).  The  manual  gives  detailed guidance  on  such  matters  as. animal carc.  training,  housing.  fceding  and methods of harncssing.  as  well as im plements suitable  for  their  use. 
The characicristics  of  thc  four  ani mals  mentioncd  above  together  with the  arguments  for  and  against  cach 
Newly  trained  for  the   cart  in   Benin 
Sccond,  the  tractor  is  an  indivisiblc 
Ploughing paddy  with a bugalo  in  the  Lao  People's Denocratic Republic 
unit   and   when   used   for   light 
tions   such   as   hauling  light   loads  or 
opera 
mowing,   which  can  be 
plishcd  by   a  puir  of  oxcn,  the   com 
casily   accom 
deploymcnt 
Parative  operating  cost  nmust  be  taken 
al  the  hourly  rates,  i.e.,  TSh  165 
(OSS  20)  comparcd  with  TSh  6  (US 
$ 0.72).  Fifty  pairs  of  oxen  allow  a 
considerably than  greater  lexibility  of 
All   in  all  the 
conclusion  is    inescap 
one  tractor. 
able  that 
advantage   lics    with    the 
cularly  in    a country   wherc   oxen, foreign    par 
cconomically  thc 
balance  of 
are  often  the  same  as  those  in  which animal  hcalth  problems  are  greatest and,  in  consequence,  the  demand  for managenent  skills  highest.  Tsctse infested  ascas  usually  fall  into  this catcgory. 
For  these  and  other  rcasons  it  is unlikely  that  animal  cultivation  wi!l be a feasible  solution  to  problems  of and mechanization               thus  alternative      in  areas    engine   of  power         this  kind,    for them has to be sought. 
species,  as  given  in  the  manual,  are sum1marized  below. 
The horse Advantages 
It   is 
a  friendly   animal   that   be 
Cxchange  is   not  casily  availablc,  farm 
SiZc   is   nmodest,  and  labour 
a   limiting 
cultivable  land. 
One      major     problem     frequently 
factor   in   arcas   of   good, 
supply  not 
stands  in  the 
Characteristics of draught animals 
and  methods  of  using  them 
CIIOICE   OF    SPECIES 
of 
Ol 
no 
mcchanization.   way         areas   animalI-powered                 where there       Many   animals       work       bave    been    uscd   for 
CXtremely   dilficult  1o   instil carc,   it    IS 
animal 
tradition   among  arable  farmers 
draught 
or  transport, the  prin-
ownership  and 
e 
ne   heccSsary   management  skills  and 
Contidence  and 
into  them 
cipal  bcing  horses,  oxcn,  water  buf 
faloes,  donkeys,  Tlhe  choice  camels,  between  nmules  and 
comes  atlached  to   its   owner. 
It  enjoys  a  certain  prestige  in Arica,  so  that  the  farmer  is  in clined  to  give  it  greatcr  care  than he  would  an  ox. 
work.  is easy  to  train for all  kinds of handle,  When  working,  docile  and  it  is  can fast,  be  casy  simply,  to casily  and  accurately  controlled. 
Disadvantages 
It  is  often  too  light  in  Africa, where,  under  average  condit ions of  imaintenance,  is  weight  may  be 250  to  280  kg. 
It has  a  rather  weak  constitution 
of   animals 
deands. 
summarized           goats. 
Oxcn,    donkeys in und    camcls 
manual       is     horses, 
well 
and  nccds  special  care  and 
atten 
USc 
sympathy  that  the 
Thesc arcas 
un     FAO 
(FAO,   1972)  originally  published  by 
tion  and  is  costly  to  maintain. 
I  is   susceptible  to   trypanosomi asis. 
5 tires     fairly     quickly     when working. 
It   is   expensive. 
Its  harness  is   costly. 
The ox 
dvantages 
It  works  slowly  but  unflaggingly. IL  is  hardy  and  strong  and  easy to  fecd. 
Its  harnessing  is  simple  and  the yoke  can  bc  made  locally  at  low 
cost. 
Its  purchasc  price  is  attractive(in some  countries  1 pair of  oxen  = 
1 horse). 
At  the  end  of  its  working  life,  it may  be  sold  for  mcat,  and  is  in fact  often  sold  for  this  purpose after  a period  of  fattening. 
sadvantages 
It is not a friendly  animal, at lcast so  far  as   many  African  farmers are  concerned  wvho   are   unaccus tomed to the carc of animals.   The farmer    considers    the    ox    solely fronm      the    point   of    view    of   its working  value. 
The  ox   nccds   relativcly  extensive grazing  arcas. 
It   appcars  to   be   more  difficult  to train    than   the   horse   and   nceds more  manpower  to  control  it. When   working,  it    is   slow. 
The  donkey 
vantages 
It   is   a friendly,   hardy   and   quiet animal. 
It  is  economical  to  buy  and  can 
TABLE   3. 
Work  potential  of  man,  various  animals  and  a  50-kW  tractor 
lem 
Pull  (N) 
Speed (m/s) 
Power  (KW) 
Daily  work   hours  (h) Daily  work  output  (MJ) 
Man 
Horse 
Ox                Donkey 
Tracto 
500 
I.0 
0.50 
6 
0 
500 
1.0 
0.50 
9 
400 
1.0 
0.40 
6 
10 000 
0.20 6 
2.5 25 
S-24 720-2 1G0 
CHOICE   OF   BREED 
It  needs  to  be  stressed  that  in  most cases   and    whencver   possible,   use should  be  made  of  local  indigenous breeds.    The  use   of  animals   trans ferred  within  the  country  or  imported animals   should   be  avoided. 
CHOICE  OF   INDIVIDUAL 
Within  a particular  species  or  breed, the  qualities  to  be  looked  for  when choosing  a  draught  animal  are  as follows: 
Confornation.   As  regards the ox,  as a draught  animal,  it  should  be    power ful,   compact,  sturdy  with     well-devel oped  muscles,  particularly  those  of  the back   and   the   hindquartcrs.     Its   legs should  bc strong  and  as  short as   pos 
sible  ("low  on  thc  ground"). 
Its  chest 
should be ample and deep. 
In  the  case  of  draught  horses,  they should  have,  in   addition  to   the  same power  characteristics  as   the  ox,  short and straight shoulders, as  long  forelcgs and  as  strong  muscles  as  possible  (for 
leverage).   sloping   hindquarters   and short  hindlcgs. 
Character.  Whatcver  the  species.  a calm and docile animal without vices (tendency to kick or to butt) should be sought. 
Age.  In  the  casce  of  the  ox,  training starts  at  about  two  or  thrcc years  of age;  in  the horse. at about three years. Sex.  Gelded  males  are  usually  used but the mare, the she-ass and the cow can  also  be  used. 
UTILIZATION  AND  WORK  TO  BE  DONE 
The ox.  The  ox  is  particularly  suit able  on  fairly  heavy  soil.  for  relativcly deep work  (15  cm). for lifting ground nuts,  digging-in  green  manure,  pulling loaded carts  and  drawing water  from wells. 
The horse.  The horsc is mainly used on  light  soil  for  shallow  row-crop work (such as for groundnuts, sorghum 
be 
draught  work   and  load   carrying). 
1t   is   paticnt  when 
It  is  easy  to  train  and  is 
produce.    maintaincd 
on     local   farm 
working 
intelligent. 
(light 
ndvantages              It 
strength.          It 
is 
very 
light   and   limited   in 
and harness         susceptible    sorcs.  trypanosomiasis 
It   is 
tires  easily  if  driven  too  fast. 
to 
"his 
The  dromedary 
an  awkward  temperament.            and   sonctimes 
aitficult 
animal 
to   train patient  and   hardy 
is 
Cultivating  rice   with  bulalo  in   Indonesia Single  ncck  yoke  (China) 
Double  neck  yoke  (lndia) 
Ox   with  collar  harness 
Back strap 
Neck strap 
Saddle 
Breech slrap 
Breast band 
and  millct).  and  for  pulling  the  seeder 
or  the  light  hoe.    No other animal  can compare   with    it    for    pulling   light, shafted  carts   or  cabs   but   it   is    not usually  strong  enough  (at  any  rate Africa)  for   ploughing  or  pulling  the groundnut  lifter. 
The  donkey.   The  donkey      suitable for  light  draught  work  and  load  car rying,  and  light  work,  such  as     weced ing.   hoeing,  sowing  or  the  use  of  the single row planter. 
The  dronedary.  The  dromedary  is used  mainly  as  a beast of  burden  and, in arid  regions, for drawing water. 
There  is little doubt that for draught purposes   in   Tanzania  the   immediate choice  is  narrowed down  to  oxen and donkeys.   although   the   possibility  of employing   mules   might   also   be   ex plored   as   the   opportunity   arises. 
WORK  POTENTIAL 
Table  3 shows  the  work  capacity  of man,  various  animals  and  a  50-kW tractor  in  terms  of  mcchanical  power and  work  output.  The data  available are  somewhat  variable,  as  may  be expected  for  different  breeds  and  for the  varying  condition  of  the  animals and  of  the  environment  in  which  they are  found.  The  values  in  thc  table may,  therefore,  be  uscd  for  general guidance  and  comparison,  but  should be  applied  with  discretion.  The  pull and  power  quoted  for  animals  are bascd  on  figures  for  continuous work output.  For  short  periods  they  can be  greatly  exceeded  (by  a factor  of five  or  more)  if  compensated  by adcquate  rest  periods. 
HARNESSES 
Harnesscs  for  work  animals  fall  into three  broad  categories- yoke,  collar or  breastband.  Some  cxamples  are illustrated  in  Figure  3. 
Basically   the    yoke    is     a  wooden cross-piece   to   which   the    animal.  ap plies a pushing forcc  from  the  forchead 
(head  yoke)  or  neck  (neck  yokc). 
The 
Donkey  with  breast  band  harness Iigurc 3    Vurious  lypes  of  harness 
yokes  niay  be cither  single  or 
There  are   very   many  regional    varia 
double. 
tions   in   design  (Hoplen,   1969).    The 
double  ncck  yoke  is  the  most  widely 
7 Horses  carrying  agricultural  equipment  in  Ecuadur 
Donkeys  used in  pulling  carls  in  Uppcr  Volta 
used  with  horses  and 
uscd  mcthod  for  harncssing  oxen, bcing  sinplc  to  makc,  chcap  and  cf fective.  Its  suitability  for  oxcn  rests on  the  fact  that  oxcen  arc  strong shouldcred  but  rather  wcak  across  the breast. 
In   contrast   the   main   strength   of horses  and  donkcys  is   in   their  brcast and  shoulders.    For  high  pulls  a col lar   harness   is     most   suitable.     This should   be   adaptcd   to   thc   individual animal   so   that   it    is    well-fitting.     It must  be  padded  with  a soft   lining. 
be   For lighter  work  a breastband  nay not   oxcn.      The   illustration    donkeys,      shows but a Tull     breastband   harness   for   usc   in pulling   a  cart.        Simpler   types    con Sisting  cssentially  of  a breastband  and 
cases. 
neckstrap  only 
may   bc  uscd  in  other 
Ihe   accuracy   and 
CONTROL 
most  cfficient  and  cffective  work  that 
mects  the  crop  requiremcnts  of given 
arcas  under  their  prevailing  cnviron 
mental  conditions.  The  farn1  ma 
chinery  available  has  becn  allowed 
to  dictate  the  system  of  cultivation 
adopted,  leading  to  sub-optinal.  and 
sometimcs  disastrous  results.  Efforts 
are  now  being  made  to  nake  a truc 
asscssmcent  of  the  machinery  nccds 
of  ccrtain  countrics.  For  cxample, 
in  Botswana  the  "Dryland  Farming 
Rescarch  Scheme"  (DLFRS)  and 
"Evaluation  of  Farming  Systenis  and 
Agricultural  Implements  Project" 
(EFSAIP)  have  becn  in  operation  for 
four and threc years respectively.  This 
approach is coupled  witlh a full  assess 
ment  of  the  encrgy  requirements  in 
order  that  minimum-energy  syslems 
(usually  associated  with  "minimum 
tillage")  can  be  established.  This  is 
of particular value when systems with 
greatly 
performed 
by 
draught 
quality   of   work 
low-power   inputs   are   being 
devel 
ttveness  of 
animals 
is 
ator  should  be 
influenced   by   ease  and 
control. 
With a 
able  to   guidc  both  the 
Ideally  the 
effec 
oped  from  scratch. 
The  nced  to  develop  minimum  till age   and   minimum-encrgy-production 
implement   and   the  animal,  dispensing 
opcr 
systems, 
and    to    identify   the    farm 
Control 
separate  lcad  man. 
machinery  to  inplement  them.  is 
recciving  attention  at  the  Uyole  Agri 
guidance 
gular  practicc.    For  oxen, 
system, 
depends good  on 
training 
an  cffective 
may      be 
animal. 
0  the      by       means     of 
cars, 
horns    or     nosc      of       the 
ropes 
guidance 
attached 
and 
In  the 
Jatter    case   the  nasal 
septun1  nust be  picrccd  for  the  pur pose.  Uyolc  Agricultural  Centre  rcc onmend  the  inscrtion  of  a  screwcd ring  into  thc  nose  and  have  provided details  of  the  training  and  methods of  harnessing  found  cllectivc  at  the Centre  (Daily  News  of  Tanzania, 1978a). 
Farm  systems and  machinery 
FARMING  SYSTEMS 
The  mouldboard   plough   is    the   most widely  uscd   animal-drawn   implement in Tanzania.   Is predominant  use  has been  frequently  criticized  (c.g.. Bceny. 1975;      Daily     Ncws     of     Tanzania, 19786).   The  main  uscs  of  the    mould board  plough  are  for cutting  and  in- version   of   the   soil.     This   practice encourages   moisture   loss   and   in creases  the  susceptibility  of  the  soil to  crosion, both of which are  undesir able   fcatures   under  most  Tanzanian conditions.    Earlier  rescarch  work  at Tengeru  and  Ukuriguru  on  the    mech anization          crops in order     of    the   to  avoid      wheat these   and problems          cotton has  not  been  followcd  up  or cxtended to  olher crops. 
tractor   Mechanization,              powered,  has   whether     too  often      animal been  or approached   without   suficiently   con sidering   the   farming   practices   and cultivation  techniques required for the 
zania,   1978c)   and   at   the   Faculty   of Agriculture 
and  Have,  1979;  at  Morogoro  Havc  and  (Dihenga  Dihenga. 1979).  The  work  is  relevant  to  both 
animal- and  tractor-powered  systen1s. Further  projects  in  this  ield  are  cur 
cultural  Centre  (Daily  NewS   of 
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The 
MACHINERY 
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Agriculture. 
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(swing) 
Simple 
attcntion 
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rently carry  a load  of  up  to  100  kg.  Ising a light cart  it  can pull  a loud  of 300  ku. A  pair  of  oxcn  can  be  uscd  lo  pull a  cart  loaded  wilh  2  tons.  Thc  cost of  such  transport  is  low,  particularly for  small loads  over  short  distances, compurcd  with  that  of  a  tractor  and trailer. 
Conclusions 
Canel drawing an implemcnt to  eradicate Bermuda grass  in  Tunisia 
handles  and  increascd  by  raising  the handles   so   that  the   sharc  point  is inclined    downward    to    give    morc penetration.      It   is   not   possible   to control  a tincd  inmplement  in   this  way and    depth   regulation   by    means   of whccls (l-igure 4b) or skids (Figure 4c) becomes    necessary.    "Toolbar"   type implemcnts  such  as   those  illustrated become  feasiblc  solutions  from  a tech nical   and   cconomic   viewpoint.       Al though   lheavier,   more   cxpensive   and lcss     manocuvrable    than    the    light mouldboard  plough  they  can  be  fitted wilh  a wide  range  of  attachments.    I the    system    requires   a   sclection   of diferent  implements  and   machincs  it may  be  cheaper  to  buy  a toolbar  with lhe  required  attach1ments  than  the  in 
available 
cullivatcd    land 
enablcs   higher             yields    per hectarc  to  be  achievcd. 
Animal  power  provide  the nccessary  supplcment  to  human labour  at  low  cost  in  foreign  cx change  and  without  the  nced  for scarcc  and  cxpensive  managerial and technical  support. 
Existing  animal-powered  cultiva tion  systcms  in  use  in  Tanzar: could  be  improved.  particulariy from the point of view of moisturc and  soil  conservation  nceds.  De velopment  of  viatble  systcms  is  a prercquisitc  to  the  identification of  suitable  cquipment. 
Machinery  can  only  be  sclected mcaningfully  after system  requirc ments  have  becn  identiicd. 
It  may  be  neccssary  1o  devclop machinery  to  meet  specific  nceds. This  is  best  done  after  a  full evaluation  of  the  existing  ma chincry  available  has  becn  madc. 
An   increase   in 
power 
per    hcctarc    of 
crop 
can 
dividual  machines  for  each  operation. 
The "systems" approach  in the iden 
lilication 
of   farm   machincry  require 
by  work  in  Botswana  with  thc    Mak gonatsotlhe toolbar and at Uyole with a   locally  made  timber  toolbar.    An intermediate   stage,   which   has   not. perhaps,   becn    performcd    in    these cases,  is   the identification  of suitable cquipment  from  alrcady  cx isting  and often  well-iried  nachincry.   Investiga tions   of  this   nature  are  being   con ducted   at   the   Kenya    Agricultural Machinery  Unit  at  Nakuru. 
TRANSPORT 
Transport  is   an  esscntial  feature  of far1ning   systems.     In   many   circum stances,  it  may  be looked  upon  as  an independent  operation  such  as  in  the Lransport  of  water  and  firewood  for domestic  use.     For  both  purposes  it has is surprising             so  far  been  that so the   little use developed            of  animals  in Tanzania. 
The donkey, as  a pack animal, can 
References 
DrENGA, H.0. &  HAVE,  H.  1979.  Direct planting  (herbicile  use):  a  preliminary Enginecring  Morogoro,  note on  the and  efects  Land  on  muize  Planning,  production. 
general   village  transport,  as   well as  for  farn  usc,  necds  to   be   in vestigated. 
on   the  cfects of  farm  nechanization  on production and cmploynent.  Rome,  FAO. comparisons            TuIzania     &  DIHENGA,               of   reduced           a  concept.         H.0. tillage   1979.      Morogoro,      Cost 
systems 
in 
Departnment  of  Agricultural  Engincering 
The 
greater 
use   of   animals   for 
ments    and 
cquipment   to   mect 
them 
in    the 
development   of 
is    typified 
BEENY,    J.    . 1975. 
lion  study.     UNDP 
Agricul tural 
report  to   the  United 
mechaniza 
DMLY 
Republicof   Tanzania. 
FAO|AGO/DP/URT/75/018. Rome,  FAO. 
HAVE,   H. 
draught    animal    mechanization. 
News, 
NEWS   OF      TANZANIA.      1978a..     Toward 
sity of Dar-es-Salaam.   LDepartmental 
Departnnent   of   Agricultural        Univer 
Daily 
A  look 
port  No.  5. 
FAO.    1972.    The employment of draught animals  in  agriculture.     Rome. 
GILES,  G.W.  1975.  The  reorientation  of 
Re 
DMLY 
and  Land  Planning,  University  of Salaam. 
8June   illage  .1978,     lools p. in 4. Tanzania.   Daily  News, 
A 
NEws 
1 June   197S,   p.   4. 
oF       TANZANA.      1978b. 
DALY 
Dur-cs 
Department  Report   No.   2. 
HoPFEN,  H.J.  1969.  Farm  implements  for 
Rome.     FAO 91. 
agricultural   meclhanization   for   the 
de 
Agricultural              arid and  tropical      Devclopment           regions.   Paper  No. 
10 
Junc   1978, crop   p.  4. rotation.      Daily      News,   22 
Case 
NEws   OF 
for 
TANZANIA, 
1978c.     The 
veloping countries:  policies  and  attitudes, 
meeting  action  programmes,  of the  FAOJOECD  In:  Report  expert on panel  the 
LoNNEMARK,   H. 
1967.    Multifarm   use   of 
farm   tural machinery.                Developncnt  Paper  No.   8S. 
Rome.    FAO    Agricul

Summery

Summary: Animal Power in Agricultural Production Systems

Animal Power in Agricultural Production Systems

Document Overview

This document, authored by F.M. Inns (Professor of Agricultural Engineering at the University of Dar-es-Salaam), examines the role of animal power in agricultural systems, with special reference to Tanzania. Originally presented at the Sixth Scientific Conference of the Tanzanian Society of Animal Production in May 1979, it provides a comparative analysis of animal power versus mechanized alternatives like tractors.

Key Findings

Power Sources in Agriculture

The document identifies three primary power sources for field operations:

Human power - Intermittent force (e.g., hoeing)
Animal power - Continuous force (e.g., pulling ploughs)
Heat engines - Tractors (petrol/diesel)

All three share the same basic chemical process: oxidation of their fuel supply.

Economic Comparison: Tractors vs. Oxen

Feature	Tractor (50 kW)	Pair of Oxen (1 kW)
Initial cost (TSh)	125,000.00	4,000.00
Total cost per hour of use	165.00	5.95
Foreign exchange cost per hour	80.00	0.40
Cost per kWh	3.30	5.95
Maximum pull (kN)	6	1
Potential work per day (hours)	24	5

Key conclusion: While tractors provide cheaper energy per kWh, oxen have significantly lower foreign exchange costs and greater flexibility for smallholder farms. The economic advantage generally lies with oxen in areas with limited foreign exchange, modest farm sizes, and available labor.

Animal Power Characteristics

Comparison of Draught Animals

Animal	Advantages	Disadvantages
Horse	Friendly and enjoys prestige Easy to train Fast and responsive	Often too light for heavy work Weak constitution, costly to maintain Susceptible to trypanosomiasis
Ox	Works slowly but steadily Hardy and easy to feed Simple, low-cost harnessing Can be sold for meat after working life	Not considered friendly by some farmers Needs extensive grazing areas More difficult to train than horses Slow working speed
Donkey	Friendly, hardy, and quiet Economical to buy and maintain Easy to train and intelligent	Limited in strength Tires easily if driven too fast Susceptible to trypanosomiasis

Work Potential Comparison

Power Source	Power (kW)	Work Output (kWh/day)
Man	0.07	0.3
Donkey	0.3	1.5
Ox	0.5	2.5
Pair of oxen	1.0	5.0
50-kW tractor	50	500

Implementation Considerations

Harness Types

Three main categories of harnesses are identified:

Yoke - Wooden cross-piece (single or double) for oxen
Collar - For horses and donkeys (high pulls)
Breastband - For lighter work with horses and donkeys

Farming Systems

The document criticizes the predominant use of mouldboard ploughs in Tanzania, which can lead to moisture loss and soil erosion. It advocates for:

Development of minimum-tillage systems
Proper assessment of machinery needs based on farming practices
Consideration of toolbar-type implements with various attachments

Transport Applications

Animal power has significant potential for transport applications:

A donkey can carry up to 100kg as a pack animal
A pair of oxen can pull a cart with 2 tons of load
Animal transport is economical for small loads over short distances

Conclusions

Increased power input per hectare enables higher crop yields
Animal power provides cost-effective labor supplementation with low foreign exchange requirements
Existing animal-powered systems could be improved for better efficiency and soil conservation
Machinery development must follow system requirements identification
Custom machinery development may be necessary after evaluating existing options
Greater use of animals for village transport needs investigation

Original Document: "Animal Power in Agricultural Production Systems" by F.M. Inns, Professor of Agricultural Engineering, University of Dar-es-Salaam. Reproduced from "Animal Review" n. 34-1930, presented at the Regional Preparatory Meeting on New and Renewable Sources of Energy, Addis Ababa, 12-16 January 1981.