African
Journals Online
UNISWA Journal of Agriculture
Abstracts (Vol. 8)
Response of cowpea (Vigna
unguiculata (L) Walp) varieties to leaf harvesting in
Botswana.
S. K. Karikari and G. Molatakgosi
In Botswana, cowpea (Vigna unguiculata (L) Walp) is
not only grown for grain but also the leaves are
harvested and used as vegetable. The effect of leaf
harvesting on grain yield under Botswana conditions is
not known. This study was, therefore, undertaken to
assess the response of four cowpea varieties namely
Tswana, Blackeye, ER 7 and TVx 3236 to leaf harvesting.
Under field experiments carried out over two growing
seasons, effects of four levels of leaf harvesting (0,
25, 50 and 75%) on growth and grain yield were
determined. While harvesting of up to 50% of leaves
increased grain yields of Tswana and Blackeye, these were
depressed when up to 75% of leaves were harvested. Also,
all leaf harvesting treatments had significant negative
impact on ER 7 and TVX 3236 grain yields. The results
suggest that Tswana and Blackeye cowpeas could be
developed for the dual purpose of leaf and grain
production in Botswana and other areas where cowpea
leaves are relished as a vegetable.
Development of a
computerised rangelands resource information system for
Swaziland.
M. Absalom Manyatsi
The objective of this paper was to produce a
computerised land resource management tool for
identifying priority areas for soil conservation and
sustainable management of rangeland resources. The
results of satellite image analysis were used to produce
maps showing the status of soil erosion and bush
encroachment in the country. This was achieved by
classifying the land cover map into five soil erosion and
three bush encroachment classes, and highlighting
critical areas of land management. Data on livestock
inventory, rangelands resources, and status of land
degradation were integrated to produce a computerised
resource information system for Swaziland, which will
assist in decision making for monitoring and management
of rangelands resources; its application is demonstrated.
The resource information system developed has the
capability for storage, retrieval, and display of both
graphical and non-graphical data in custom-designed maps
and tables.
Biomass
requirements from natural pastures for livestock grazing
and soil protection in the Eastern African highlands
E.J. Mwendera, M.A. Mohamed Saleem & Alemu Tadesse
The problem of seasonal shortages of herbage
production from natural pastures in the Ethiopian
highlands was investigated. This was done by comparing
the available biomass amounts on the pastures with
biomass amounts required for livestock grazing and for
protecting land slope from soil erosion within a given
slope limit at different times of the year. It was
observed that the pattern of biomass availability and the
requirements for livestock grazing and soil protection
vary seasonally, as grazing is concentrated in different
parts of the watershed at different times. It was further
observed that from March to September feed
supplementation is necessary since the available biomass
quantities from natural pastures and crop residues on
slopes above 3 % are generally inadequate to meet
livestock and soil protection requirements. However,
with changes in the grazing management to regulate
grazing pressure, herbage production on these slopes may
be increased to adequately meet livestock needs while
protecting the soil from erosion. Herbage production
could further be improved through fertilizer application,
provision of feed supplements during times of shortfall
in biomass, and/or by leaving animal dung on the
pasturelands instead of collecting it for fuel and other
uses. The cost of feed supplements relative to the cost
of restoring degraded land as a result of allowing
grazing to exceed the safe limits should be investigated.
Feeding strategies for
sustainable cattle production on Swazi nation land
G.W. Ocen
Cattle play a pivotal role in the social and
economic welfare of the Swazi people. The major challenge
however, is how to ensure that cattle production
continues to meet the needs of the present Swazi
generation without compromising the ability of future
generations to meet their own needs. This article
describes the characteristics of the cattle production
environment on Swazi nation land (SNL), highlighting the
linkage between the production environment and cattle
productivity. The article singles out nutrition as the
most important factor limiting cattle productivity on
SNL, and yet in Swaziland, it argues, there exist vast
feed resources that are unused or poorly utilised and
could make a major impact on cattle production. It then
goes on to present an analytical framework for a feeding
strategy that ensures sustainable cattle production
– a strategy that mobilises all the feed resources
in the country. This strategy is supported by research
data from feeding trials involving feeds available in
Swaziland. The study shows that there is need to develop
low-cost feeding packages utilising crop residues and
agro-industrial by-products especially for
winter-feeding, and to adopt integrated farming systems
in which livestock production complements crop production
for efficient and sustainable use of resources and
environment protection.
Influence of
molasses on the intake of browse by goats
J.W. Ng'ambi
Two 3 x 3 Latin square design experiments with
twelve growing goats (small East African crosses) in each
were used to examine the influence of molasses on the
intake by goats of browse offered with a supplement. The
first experiment examined the responses in voluntary
intake when molasses was sprayed onto Cassia
siamea leaves (0.04kg molasses per
kg browse) as compared to when molasses and Cassia
siamea leaves were offered
simultaneously yet separately. Goats ate more Cassia
siamea leaves (0.20kg OM per
animal per day) when the leaves and molasses were mixed
than when the leaves and molasses were offered separately
(0.10kg OM per animal per day) (P<0.01). No
differences in digestibility were observed between
treatments (P>0.01). The overall effect of spraying
molasses on the browse was that total daily diet
digestible organic matter intake was increased from 0.37
to 0.46kg per animal, an increase of 24% (p<0.01).
The second experiment examined the response in
voluntary intake of Sesbania sesban
leaves by goats when the leaves were either sprayed with
molasses or when the leaves and molasses were offered
separately. The response was small and statistically not
significant (P > 0.01). It is concluded that mixing Cassia
siamea leaves with molasses
increased the intake of the leaves by goats and this
offers a practical method of increasing the feeding value
of this browse.
Voluntary intake of maize
stover supplemented by urea lick in dorper and local
Malawi sheep.
S.K. Chikagwa, M. Blummel, J.P. Mtimuni and J. Banda
Ten Dorper (16.0 to 37.0 kg) and Local (12.0 to
28.5kg) rams were used to determine the voluntary intake,
digestibility, nitrogen retention of maize stover and
live weight change. Dietary treatments were maize stover
offered to meet the requirement for maintenance with urea
lick, 1.5 or 2 times maintenance with urea lick. Stover
stems had higher fibre content (78.5 % NDF) and lower
content of nitrogen (0.34 %) and metabolizable energy
than leaves. The sheep consumed leaves and rejected all
stems. Intake of maize stover increased (P < 0.001)
with increasing level of feed offered above maintenance.
Sheep offered stover at 1.5 times maintenance had
highest intake of stover (24.7 g/kg body weight) and
nitrogen (1.5 % feed intake). There were no differences
in intake between levels higher than maintenance.
Digestibility was highest (P < 0.01) for sheep offered
stover at 1.5 times maintenance. Higher nitrogen intake
of stover diet increased digestibility and intake of dry
matter owing to the stimulation of microbial activity.
Liveweight gain was higher (P < 0.05) for sheep
offered stover at 1.5 times maintenance (52 g/day)
reflecting high intake, while sheep offered stover at
maintenance lost weight (-105 g/day). Metabolizable
energy intake increased with increasing total dry matter
intake. Nitrogen balance was positive for diets with
nitrogen intake of more than 1 % of feed intake. Nitrogen
retention increased with high nitrogen intake. Breeds did
not differ in voluntary intake. Dorper sheep had higher
digestibility, higher nitrogen retention and gained more
weight than local sheep (P < 0.001). It was concluded
that for sheep fed low quality maize stover, voluntary
intake, digestibility, nitrogen retention and liveweight
gain increased by offering greater amounts of stover with
high nitrogen intake (1 % feed intake). Differences in
digestibility suggest that the Dorper breed could be a
valuable resource for sheep production even in areas
where low quality maize stover limit the use of European
breeds.
Mohair production trends in
Lesotho between 1935 and 1990
J.W. Ng'ambi and A. Belete
An exponential regression equation of the form Y =
Aebx was used to estimate trends
and relationships in Angora goat numbers, mohair
production and mohair yield per goat in Lesotho between
1935 and 1990. Angora goat numbers, mohair production and
mohair yield per goat increased at annual rates of 1, 1.8
and 1.1%, respectively (P < 0.01), between 1935 and
1965. There is some indication that during this period
growth in mohair production depended on annual growth in
both goat numbers and mohair yield per goat (P <
0.01). During years of independence (1966 to 1990) annual
goat numbers, mohair production and mohair yield per goat
remained largely stagnant (P > 0.05). It is suggested
that in future emphasis should be on increasing mohair
production through improvement of mohair yield per goat.
The use of single working
donkeys (Equus Asinus) in light tillage operations in
Zimbabwe.
Dube, Z, L. R. Ndlovu and E. Nengomasha
Draught power shortage is a major constraint to
agricultural production in the smallholder farming sector
of Zimbabwe. A study was conducted at Matopos Research
Station to investigate the feasibility of using single
working donkeys (Equus asinus) in
light tillage operations as a means of alleviating
draught power shortage. Twenty-four donkeys were used in
the study. They comprised 12 light (<130 kg) and heavy
(>130 kg) donkeys which were equally representative of
empty, pregnant, entire and castrate sex categories. The
donkeys were characterized in terms of linear body
measurements. Work output and physiological parameters
were measured from single working donkeys in ripping.
Linear body measurements of donkeys were
significantly (P<0.05) influenced by sex and live
weight. Height at withers in heavy castrate males was
110.0 cm whilst light empty females, the smallest group
stood at 98.7 cm. The donkey weights ranged from 113 kg
to 162,7 kg. Linear body measurements, particularly live
weight, were good predictors of work output of single
working donkeys. Work output was significantly influenced
by soil type (P < 0.05) and live weight (P <
0.001). Total work done by single-hitched donkeys ranged
from 142.3 kJ to 423.3 kJ on heavy clay and from 151 kJ
to 514.7 kJ on red loam soils. Heavy donkeys did work
ranging from 301.3kJ to 514.7 kJ while light donkeys
covered work ranging from 151 kJ to 271 kJ. Sex did not
have a significant (P > 0.05) effect on work output.
Single hitched donkeys worked for a maximum period of 15
minutes per trial. They also experienced changes in
rectal body temperatures from pre-work resting values
ranging from 37.7oC-38.2oC
to 39.2oC - 39.7oC
at work stoppage. Heart rates changed from 52.2 +
2.28 prework to 113.7 + 3.20
beats/minute at work stoppage. These changes were
associated with fatigue signs.
Factors associated with
access of rural women to technology in Swaziland
K.J.B.Keregero and M.P.Dlamini
A descriptive, correlational study was conducted
to: describe the channels through which rural women
obtain information regarding technology, and factors
promoting access of women to technology; determine the
contribution of technology to socio-economic development;
and describe the relationships among factors promoting
access to technology and among benefits accruing from
such access. A validated and field tested interview
schedule was used in data collection. The radio,
agricultural extension officers, friends and neighbours
were identified as important channels for information
regarding technology for rural women. Access to land,
sound family relationship, affordability of raw materials
and support from husband promoted access of rural women
to technology to a great extent. Access to technology
promoted increased self-confidence, increased
self-reliance, improved family health and increased
ability to meet family financial obligations. The factors
promoting access to technology were found to be
interrelated, just as were the attendant benefits.
The relationship between
high school students' academic performance in science and
agriculture.
Leonard M. Zwane, and B. M. Dlamini
A descriptive comparative study to determine
agriculture students= performance in science as compared
to agriculture found superior performance in science than
in agriculture. Students= performance in science was
highly correlated with performance in agriculture.
Students from urban, mission and single schools performed
significantly higher than students from rural,
government, and mixed schools. Also, students from
Manzini and Hhohho districts, generally, had
significantly higher scores than students who came from
Lubombo and Shiselweni districts. Science, school
classification (single/mixed), and gender (male/female)
predicted academic performance in agriculture.
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