Duncan, Alan J.

Fraval, S.

Mutua, J.

Notenbaert, A.

Robinson, T.

Watmough, G.

CGSpace

Exploring the Role of Seasonal Variation in Livestock Feed Composition on Diet Quality and Methane Emissions in Kenyan LivestockJ. Mutua1, 3, A. Duncan2,3, S. Fraval1, T. Robinson3, A. Notenbaert4, G. Watmough11School of Geosciences, University of Edinburgh, UK2International Livestock Research Institute, Kenya3Global Academy of Agriculture and Food Systems, UK 4Independent Researcher, UK5Alliance of Bioversity International and CIAT, Kenya• Responsible for 11-17% of total global greenhouse gas emissions.• Emissions primarily from enteric fermentation and manure decomposition.• Diet is a key determinant of production and GHG emissions from the livestock sector.Livestock Sector and Greenhouse Gas EmissionsVariation in the Quality of Livestock Feed Items• Nutritive value of feed items varies widely.• Higher variation exists across geographical zones and seasons.• Types of crop residues fed to livestock are determined by the crops grown in a specific region.Data source: SSA FeedsRole of Feed Composition in Diet Quality and Emissions• Quality of livestock diet is intricately shaped by feed composition.• Diet of better quality is linked to lower GHG emissions.• Feed composition varies both spatially and temporally.• Year-round feed composition fluctuations alter diet quality and emissions. Data source: FEASTCurrent Livestock Emission Estimates using Global Models• Livestock diet data is based on expert opinion.• Diet composition data is available as a stable annual distribution.• Models unable to account for seasonality in diet composition.• Ground measurement has been done in limited locations.Modelling Implications of Diet Changes on Methane EmissionsFeed productionFeed compositionDiet qualityEnteric emissions-Species-Breed-Age-Physiological status-Live weight and gainManagement practicesClimate factorsProduction system characteristicsMonte Carlo simulationAssumption: Animal diet is based on feed production at a pixel.Tier 2 methodSpatial analysis-Crop distribution-Land use/ cover-Livestock feed quality information-Pasture-Crop residue-Cultivated forages-ConcentratesResults: Livestock Diet Composition• Livestock diets vary across the landscape.• Coarse stemmed cereals and legume crops are prominent in the central highlands.• Western Kenya has a diverse mix of feed resources including cultivated forages• Arid and semi-arid areas are dominated by pasture.Results: Livestock Diet Quality• Diet quality varies across livestock systems (Mean=581.3 g/Kg DM, IPCC default value = 550 g/Kg DM). • Greater variability in mixed (crop and livestock) systemsResults: Methane Emissions• Notable variation exist between and within production systems.• Highest dry matter intake in the mixed systems.Production systemAgro-ecological zoneLive weight (Kg)Metabolizable energy requirement (MJ/head/day)Dry matter intake (Kg)Methane production (Kg/head/year)Livestock onlyArid 182.8 42.6 4.8 36.6Humid 254.6 60.9 6.9 52.0Temperate 261.2 59.5 6.7 50.9Mixed rainfedArid 203.1 49.9 5.6 42.4Humid 282.9 71.8 8.0 60.1Temperate 290.2 67.3 7.5 56.4Mixed irrigatedArid 213.3 61.9 7.2 54.6Humid 297.1 79.4 8.9 67.5Temperate 304.7 74.9 8.4 63.8Other Tree based 270.0 59.3 6.7 50.8*Temperate includes tropical highlandsResults: Sensitivity of Methane Emissions to Changes in Diet Composition• Notable variation exist between and within production systems. • Livestock only and tree-based systems have relatively low variability.Does the Seasonal Variation in Diet Quality Matter?• It does matter when comparing it to an annual value.• Highest variation exist in mixed systems.• Substantial spread of estimated methane emissions. Production systemAgro-ecological zoneVariance(kg/head/year^2)Standard deviation p-valueLivestock onlyArid 0.6 0.8 0.727Humid 0.8 0.9 0.181Temperate 23.1 4.8 0.000*** Mixed rainfedArid 14.4 3.8 0.005**Humid 26.3 5.1 0.001*** Temperate 14.2 3.8 0.049* Mixed irrigated Arid 12.0 3.5 0.002** Humid 27.4 5.2 0.000*** Temperate 41.2 6.4 0.000*** Other Tree based 2.3 1.5 0.240*Temperate includes tropical highlandsImplications and Conclusion• Diet composition varies by location and is climate-influenced.• Seasonal fluctuations in feed availability alter diet composition.• Livestock diet impacts methane emissions, especially with changing feed composition.• These seasonal changes need to be incorporated in livestock emission assessment models.Questions?

Exploring the role of seasonal variation in livestock feed composition on diet quality and methane emissions in Kenyan livestock

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Exploring the role of seasonal variation in livestock feed composition on diet quality and methane emissions in Kenyan livestock

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