Abstract:
The potential for incorporating forage legumes in intensive smallholder crop/livestock
farming systems was assessed in a study conducted in Masaka district, Uganda from
2002-2004. The first part of the study consisted of a diagnostic survey to characterize
the production system and together with farmers identify appropriate technologies to
improve feed production and animal productivity. This was followed by (i) a trial to
evaluate the effects of intercropping lablab with maize or forage legumes (Centrosema
pubescens, Macroptilium atropurpureun and Desmodium introtum) with elephant
grass (Pennisetum purpureum) on grain yield and fodder production, (ii) a feeding trial
to determine the response and profitability of lactating crossbred cows fed forages
from an intercrop of maize or elephant grass with forage legumes supplemented with
legume hay and a homemade concentrate and (iii) a participatory technology
evaluation survey to assess the benefits and constraints from improved forage
technologies to the production system. The feeding trial, consisted of 4 dietary
treatments in which a homemade concentrate (HMC) was supplemented to the basal
diets of: elephant grass/legume fodder (EGL) and lablab hay (LH) [Treatment 1]; EGL
+ LH + calliandra leaf hay (CLH) [Treatment 2]; and elephant grass fodder fed
together with maize/lablab stover (EGML) + CLH [Treatment 3], A fourth treatment
was elephant grass fodder served as a control [Treatment 4],
Diagnostic survey showed that about 70% of the respondents were women. Age at
first calving, calving interval and lactation length averaged 26, 15 and 8 months,
respectively. Elephant grass was the predominant fodder grass planted by over 98 %
of the respondents while legumes (herbaceous and fodder trees) were used by less
than 10%. Elephant grass fodder occupied less than 35% of the total farm area.
Estimated fodder DM yields were 4,171; 4,945 and 5,722 kg/ha/yr in urban, peri-urban
and rural areas, respectively There was a marked decline of about 53% in total DM
intake during the dry season with resultant protein and energy deficits estimated at
940 g/cow/day and 35.5 MJ/cow/day, respectively compared to a deficit of 190
g/cow/day and a surplus of 35.0 MJ/cow/day, respectively in the wet season. This
resulted in a decline in milk yield during the dry season of about 44 percent. Land
shortage, high cost of seed and field maintenance, were major reasons for not
planting leguminous forages. Based on total scores of the diagnostic survey and
results from previous on-station trials, elephant grass/legume mixtures, maize/lablab
intercrop, lablab hay and calliandra leaf hay technologies were selected for on-farm
trials/demonstrations to improve feed availability and overall animal productivity.
Intercropping elephant grass with forage legumes (EGL) increased (p<0.05) elephant
grass plant growth (79 cm) and total fodder DM yields (12,211 kg/ha/yr) by 12 and 22
percent, respectively when compared to the monocrops. Legumes contributed about
12% of total DM yield. Mean fodder DM yield of 6,488 kg/ha/yr observed in EGL
during the wet season was 13% higher (p<0.05) than the DM yield observed during
the dry season (5,722 kg/ha/yr). The results showed no differences (p>0.05) in mean
DM yields of legumes during the dry and wet seasons (677 and 780 kg/ha,
respectively). Elephant grass/legume intercropping significantly (p<0.05) increased
CP and CP yield (CPY); In vitro organic matter digestibility (IVOMD) and Ca content
but lowered (p>0.05) the NDF content of elephant grass fodder. The contribution of
forage legumes to total CPY was 26%. Total CPY of the intercrops was higher
(p<0.05) during the wet season than during the dry season. Fodder DM, grain yields,
and cob size were increased (p<0.05) by 26, 7 and 6%, respectively when maize was
intercropped with lablab compared to monocrops (4,373 kg/ha/yr; 2,912 kg/ha/yr; 134
g respectively). Total fodder and grain yields in ML (5,165 kg/ha) decreased by about
11 and 8%, respectively in the second rains when compared with yields during the first
rains (5,806 kg/ha). On average, the CP content of ML (8.4%) was 1.9 times higher
(p>0.05) in intercrops when compared to the monocrops (4.0% CP). Maize/lablab
intercropping reduced (p<0.05) OM, DM and NDF but increased (p<0.05) P; Ca;
IVOMD and ME compared to maize monocrop. The study showed that the quantity
and quality of elephant grass fodder produced from 0.405 ha, recommended to
farmers by projects that supplied the animals, was not sufficient to supply about 4,941
kg DM and 4,392 kg CP required for a mature lactating cow of about 450 kg liveweight
for a full year. The minimum acreage required per mature cow was estimated to be i)
0.9 ha of EGL, ii) 0.405 ha of EGL plus 0.4 ha/year of ML or iii) 0.405 ha of pure stand
of EG plus 0.4 ha/year of ML.
Total DM, CP, ME, P and Ca intake increased (p<0.05) with supplementation.
Average daily weight gain and mean daily milk yield were higher (p<0.05) in
supplemented cows (Treatments 1, 2 and 3) than in unsupplemented cows (Treatment 4). Mean digestible CP and OMD of the feeds were higher (p<0.05) in
supplemented than in unsupplemented cows. Digestible crude protein (DCP) and
OMD of the feeds were higher (p>0.05) during the wet season (9.3% and 63.6%,
respectively) than during the dry season (9.0% and 63.2%, respectively). Initial BW of
the study animals did not differ (p<0.05). Overall, supplemented cows had higher
(p<0.05) BW and better body condition than unsupplemented cows. Unsupplemented
cows lost (p<0.05) an average of 183.3 g/cow/day between calving to 8 weeks
postpartum compared to 139.6 g/cow/day in supplemented cows. Body condition
changes followed a pattern similar to that in BW. Overall, unsupplemented cows lost
body condition of 0.5 (of scale of 0-9). Cows that were offered EGML basal diet
produced about 13% more milk than cows on EGL diets. Mean milk yield per cow
(10.2 Its/cow/day) was 13% higher (p<0.05) during the rain season than during the dry
season (8.4 litres/cow/day). Calves born to supplemented cows had higher (p<0.05)
birth and weaning weight than unsupplemented cows. Calves born to cows on EGML
diet had higher (p<0.05) average daily gain than those on other EGL basal diets.
Calving to first oestrus was reduced from about 50 days to 41 days in cows fed on
EGL and EGML diets. Calving to conception interval was 79 days in supplemented
cows and shorter (p<0.05) than 101.4 days observed in unsupplemented cows.
Average number of services/conception per cow did not differ (p>0.05) among the
supplemented cows but was twice (p<0.05) in unsupplemented cows. The return to
investment per Ushs 1,000 spent was Ushs 422, 479 and 1,324 on Treatments 1, 2
and 3, respectively. Cost of weeding forages accounted for over 30% of the total cost
of production. Revenue from milk yield accounted for about 95% of the total farm
income on EGL and EGML forages. Sale of maize grain increased total farm income
by about 25%.
In the post trials evaluation survey, majority of farmers identified improvement in: feed
availability, food security, milk yield and income as the major benefits from forage
legume interventions. However, high cost of forage legume seed and labour and initial
slow growth of legumes in EGL, land shortage and low DM yields of forage legumes in
EGL were major factors that would constrain wider adoption of the forage legume
technologies.
Major lessons learned were: (i) identification, testing and evaluation of forage
technologies with resource poor smallholder dairy farmers is a big challenge but
rewarding. It requires a lot of patience and commitment from all stakeholders and it
requires institutional support, (ii) A more holistic approach addressing several farmers'
constraints simultaneously is expected to give better results than isolated
Interventions.
The study therefore showed that in order to cope with a shortage of feeds during the
dry season, EGML forages supplemented with 1 kg/cow/day of CLH and 4 kg/cow/day
of HMC were superior to EGL basal forages. This was associated with a total DMI,
milk yield, ADG, a calving to conception interval and a return to investment of 12.1
kg/cow/day, 10.8 litres/cow/day, 247.5 g/day, 78 days and Ushs 1,324, respectively.
More research is however needed on simple labour saving technologies for
harvesting, drying and conserving maize/lablab stover and lablab hay. Total DM, CP,
ME, P and Ca intake increased (p<0.05) with supplementation.