The dry season availability of feed for ruminants is a major constraint in many parts of the wet-dry tropics. Smallholders make use of many different feeds to cover the gap, including crop residues, small areas of planted legumes (“fodder banks”), and opportunistic feeds cut from road-side verges. There is considerable evidence to show that appropriate tree species, when planted on smallholder farms, can be climate-smart across a wide range of situations. One such tree is Leucaena leucocephala, native to meso-America but now naturalized throughout the tropics.
Relationship to CSA
The leaves of Leucaena are highly nutritious and, when fed as a supplement to livestock, can substantially increase meat and milk yield compared with a low-quality baseline diet. The planting of species like Leucaena on a mixed farm can thus increase productivity per animal while also increasing resilience by making substantial impacts on income. At the same time, because the leaves improve the diet of ruminant livestock, the amount of methane produced by the animal per kilogram of meat and milk produced is substantially reduced. In addition, planting Leucaena trees on farms increases carbon sequestration in the soil, possibly by up to 38 tonnes of carbon per ha, representing a substantial potential addition to household income, even at current carbon prices.
Impacts and lessons learned
The use of Leucaena as a feed supplement can increase household income directly via productivity increases. For example, feeding 1 kilogram of Leucaena leaves per animal per day can nearly treble milk yields and live-weight gains (Thornton and Herrero 2010). 3 The aggregated effects of widespread adoption of this option in the mixed systems of the tropics also has substantial mitigation potential because the intensified diet could substantially reduce the number of ruminants needed to satisfy the future demand for milk and meat (in 2030, by 42 million and 52 million animals, respectively). Challenges at the local level include household labour resources, the availability of appropriate planting material and marketing know-how, but these are not insuperable barriers to the widespread uptake of this option.
Thornton PK, Herrero M. 2014. Climate change adaptation in mixed crop-livestock systems in developing countries. Global Food Security 3(2):99-107.http://dx.doi.org/10.1016/j.gfs.2014.02.002 Mixed crop–livestock systems produce most of the world's milk and ruminant meat, and are particularly important for the livelihoods and food security of poor people in developing countries. These systems will bear the brunt of helping to satisfy the burgeoning demand for food from increasing populations, particularly in sub-Saharan Africa and South Asia, where rural poverty and hunger are already concentrated. The potential impacts of changes in climate and climate variability on these mixed systems are not that well understood, particularly as regards how the food security of vulnerable households may be affected. There are many ways in which the mixed systems may be able to adapt to climate change in the future, including via increased efficiencies of production that sometimes provide important mitigation co-benefits as well. But effective adaptation will require an enabling policy, technical, infrastructural and informational environment, and the development challenge is daunting.
Wambugu C, Franzel S. 2014. Fodder Shrubs for increasing the Incomes of (Peri)urban Livestock Owners. Nairobi, Kenya: World Agroforestry Centre.http://www.ruaf.org/sites/default/files/Fodder%20Shrubs%20for%20Increasing%20the%20Incomes%20of%20(Peri)urban%20Livestock%20Owners_1.pdf In Kenya, there are about 650,000 smallholder dairy farmers and most are near cities and towns, where milk demand is high and marketing costs are relatively low. Milk is highly perishable, which is a primary reason why it is produced in and around urban areas.
Thornton PK, Herrero M. 2010. The potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics. PNAS 107(46):19667–19672.http://dx.doi.org/10.1073/pnas.0912890107 We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility.