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Climate Smart Agriculture Sourcebook

Climate-smart livestock production

Production and Resources

Livestock production and climate change

Livestock makes a key contribution to global food security. Its contribution is especially important in marginal lands where livestock represents a unique source of energy, protein and micronutrients (Chapter B2-1.1). Climate change has substantial impacts on ecosystems and the natural resources upon which the livestock sector depends. At the same time, livestock food chains are major contributors to greenhouse gas emissions (FAO, 2006). 

Livestock’s role in adaptation practices is described in Chapter B2-1.2. Chapter B2-1.3 looks at climate change mitigation options available along the entire supply chain. These options are mostly associated with feed production, enteric fermentation and manure management. Figure B2.1 summarizes the contribution the sector can make to climate-smart food systems, and the technical strategies available to livestock producers for adapting to and mitigating climate change. It also highlights the institutional elements that are necessary to harness the sector’s potential to support a shift to climate-smart food systems. 

Figure B2.1.  Summary of technical and institutional determinants of climate-smart livestock production

Source: Gerber, 2013 (unpublished)

B2-1.1 Climate change impact on livestock production - need for sustainable production intensification and diversification

Farming is the source of livelihood for one-third of the world's population. About 60 percent of the people who rely on farming for their livelihoods own livestock. Nearly 800 million livestock keepers live on less than USD 2 a day (FAO, 2011b). Livestock production is a rapidly growing sector. It accounts for 40 percent of the global agricultural gross domestic product and is crucial for food security in all regions. In sub-Saharan Africa, more than half the population keep livestock, and one in three of these livestock keepers can be considered poor (FAO, 2012).

Livestock make a necessary and important contribution to global calorie, protein supplies and important micro nutrients such as B12, iron, calcium. They produce 17% of calories consumed globally and 33% of protein. Livestock can increase the world’s edible protein balance by transforming inedible protein found in forageii into forms that people can digest. For example, in pastoraliii areas, livestock are the only option to turn a sparse and erratic biomass resource into edible products. On the other hand, livestock can also reduce the global edible protein balance by consuming large amounts of edible protein found in cereal grains and soybeans and converting it into small amounts of animal protein (Mottet et al, 2017). The choice of livestock production systems (e.g. grass-based, integrated crop-livestock) and good management practices (discussed in Chapter B2-4 and Chapter B2-5) are important for optimizing the protein output from livestock. 

Access to food derived from livestock is affected by income and social customs. Access to livestock as a source of income, and hence food, is also unequal. Gender dynamics play a part in this inequality, particularly in pastoralist and small-scale farming communities, where female-headed households tend to have fewer resources and consequently own fewer and smaller livestock, and within families where the larger and more commercial livestock operations are often controlled by men. Livestock, especially small ruminants and chicken, are key to women empowerment and gender equity. 

Livestock are also a major asset among rural communities, providing a range of essential services, including savings, credit and buffering against climatic shocks and other crises (see Chapter B2-4). In mixed systems , livestock consume crop residues and by-products (from agro-industrial processing) and produce manure used to fertilize crops (see module B5). Cattle, camels, horses and donkeys also provide transport and draught power for field operations, up to 81% in Northern Africa (Gebresenbet and Kaumbutho, 1997). With all these services, the contribution of livestock goes beyond agriculture and food security and directly supports education and human health. 

However, as discussed in Chapter B2-2.2, livestock need to be managed carefully to maximize the range of services they provide and reduce its vulnerability to the impacts of climate change.

B2-1.2 The impact of climate change on livestock production - the need for adaptation

Climate change poses serious threats to livestock production. Increased temperatures, shifts in rainfall distribution, increased frequency of extreme weather events and consequent increased heat stress and reduced water availability are expected to adversely affect livestock production and productivity around the world both directly and indirectly (Figure B2.2):

  • The most serious impacts are anticipated in grazing systems because of their dependence on climatic conditions and the natural resource base, and their limited adaptation opportunities (Aydinalp and Cresser, 2008). Impacts are expected to be most severe in arid and semi-arid grazing systems at low latitudes, where higher temperatures and lower rainfall are expected to reduce yields on rangelands  and increase land degradation (Hoffmann and Vogel, 2008). The direct impacts of climate change are likely to be more limited in non-grazing systems mostly because the housing of animals in buildings allows for greater control of production conditions (FAO, 2009; Thornton and Gerber, 2010).
  • Indirect impacts will be experienced through modifications in ecosystems, changes in the yields, quality and type and availability of feed and foddervi  crops, and greater competition for resources with other sectors (FAO, 2009; Thornton, 2010; Thornton and Gerber, 2010). Climate change could lead to additional indirect impacts from the increased emergence of livestock diseases, as higher temperatures and changed rainfall patterns can alter the abundance, distribution and transmission of animal pathogens (Baylis and Githeko, 2006). In non-grazing systems, indirect impacts from lower crop yields, feed scarcity and higher feed and energy prices will be more significant.

Figure B2.2. Direct and indirect impacts of climate change on livestock production systems

Grazing systems

Non-grazing systems

Direct impacts of climate change

 

  • increased frequency of extreme weather events
  • increased frequency and magnitude of droughts and floods
  • productivity losses resulting from physiological stress due to higher temperatures
  • change in water availability, which may increase or decrease depending on the region

 

  • change in water availability, which may increase or decrease depending on the region
  • increased frequency of extreme weather events, with impact being less acute than for extensive systems

Indirect impacts of climate change

Agro-ecological changes and ecosystem shifts leading to:

  • alteration in fodder quality and quantity
  • change in host-pathogen interaction resulting in an increased incidence of emerging diseases
  • disease epidemics

 

  • increased resource prices (e.g. feed, water and energy)
  • disease epidemics
  • increased cost of animal housing (e.g. cooling systems)

These impacts are likely to be widespread. However, they will be difficult to quantify due to the uncertain and complex interactions between agriculture, climate, the surrounding environment and the economy (Kurukulasuriya and Rosenthal, 2003; Randolph, 2008).

Livestock’s vulnerability to climate shocks depends first on their exposure, which is determined by the duration, frequency and severity of the shocks, and the location of the stocks and related assets (e.g. feedstock, housing, water points). It also depends on their sensitivity, which is determined by the breed (see module B8-3.1 for the impact of climate change on animal genetic resources), the housing or feeding system, status of animal health (e.g. vaccination rate) and the importance of livestock to the household in terms of food security and livelihoods (ICEM, 2013). A number of other factors can increase livestock’s vulnerability to climate change, especially in semi-arid and arid regions. These factors include rangeland degradation, the fragmentation of grazing areas, changes in land tenure, conflicts and insecure access to land and markets (e.g. crop residues and by-products for feed, animal products). Socio-economic factors that specifically affect disease prevalence include changes in land use, host abundance, international trade, migration and public health policy.

Box B2.1  The potential impact of climate change on breed distribution - an example from Kenya

The current geographic distribution of Kenyan Kamba cattle, as recorded in the Domestic Animal Diversity Information System (DAD-IS), was used to model their potential distribution. The system took into account several temperature and humidity characteristics of their production environment. This information served to define potential current and future habitats for this breed. Future habitats were modeled using the ‘Hadley Global Environment Model 2 - Earth System’ and four scenarios (representative concentration pathways: (IPPC, 2013) were selected. The differences between potential current and future habitats were mapped, revealing areas where habitat was lost and gained, and where it remained unchanged (Figure B2.3). 

Analyses of this kind can potentially contribute to more informed decision-making on breed management in a changing climate. They can strengthen the capacity of national governments, livestock keepers and farmers to protect and enhance food security and manage animal genetic resources sustainably.

Figure B2.3. Modeled distribution of the Kenhan Kamba cattle under four representative concentration pathways (RCPs). Areas of habitat loss appear in red, areas of no expected change in dark green and areas of habitat gain in light green.

Source: FAO, 2015.

Impact of climate change on animal health

Infectious diseases in animals and their transmission cycles represent complex interactions between hosts, pathogens and the environment (Peterson, 2006) and mainly occur following changes in the host-pathogen-environment system (Jones et al., 2008). Most of these diseases are zoonotic, i.e. may be transmitted to humans, and can have serious consequences for public health, the economy of the livestock sector and biodiversity conservation (Pinto et al., 2008).  

Climate change, in particular global warming, likely affects animal health by influencing the host-pathogen-environment system both directly and indirectly. The direct effects are more likely to influence diseases that are associated with vector transmission, water or flood, soil, rodents, or air temperature and humidity (Abdela and Jilo, 2016). Indirect impacts of climate change are more complex to disentangle and include those deriving from changes in land use and biodiversity and the attempt of animals to adapt to these climatic and environmental changes or from the influence of climate on microbial populations, distribution of vector-borne diseases and host resistance to infectious agents, feed and water scarcity, or food-borne diseases. In particular, prolonged droughts determine water and pasture shortages, which decrease livestock immunity against infectious diseases, as well as trigger livestock movements to areas at higher risk of animal diseases, determining the congregation of domestic animals around few available watering points and grazing areas in proximity to wildlife reserves. Here the risk of disease transmission is increased by the increased contact among domestic animals and between domestic and wild animals (Pinto et al., 2008). Grazing areas resulting from deforestation and changes in land use may expose livestock to novel pathogens due to increased interface between livestock and wildlife (Lubroth, 2012). These direct and indirect effects of climate change may be spatial, i.e., affecting the geographical distribution of the pathogen, host or vector, or temporal, i.e., affecting the timing of an outbreak and its intensity (Lubroth, 2012; Abdela and Jilo, 2016). However, not all organisms will respond similarly to climate change. In general, disease agents with external stages (e.g., non-host) of their life cycles, such as parasites, food-, water- and vector-borne diseases are most influenced by climatic and environmental changes. For instance, temperature increases feeding intervals and development rates of blood-feeding arthropods, while rainfall increases the availability of habitat for breeding sites. In general, global warming and changes in rainfall patterns and intensity are expected to expand the geographical and altitudinal distribution of vectors, allowing them to cross mountain ranges that currently limit their distribution (Abdela and Jilo, 2016). Furthermore, climate change can also influence livestock health through the survival of pathogens in the environment. A pathogen may emerge in new territories and host landscapes; become more aggressive, and perform a host-species jump, possibly in relation to increased host species mixing or contacts (Lubroth, 2012). 

Vector-borne diseases that are strongly associated with vector amplification due to climate variability include Rift Valley fever (RVF), West Nile Virus (WNV), Bluetongue (BTV) and Trypanosomosis. For instance, RVF in East Africa is strongly associated with extreme events, such as heavy rains and floods, caused by the El Niño Southern Oscillation events, which are expected to occur more frequently in the future as an effect of global climate change (FAO et al., 2015). On the contrary, West Nile Virus (WNV), Bluetongue (BTV) and Trypanosomosis appear to be strongly influenced by global warming and raise in temperature (Paz, 2015). Soil-borne diseases, such as Anthrax, are also affected by precipitation variability. Livestock and wildlife likely get infected with Anthrax while grazing and ingesting forage or soil contaminated with Anthrax spores, browsing on vegetation contaminated by carrion flies, or by percutaneous exposure from biting flies, and possibly spore inhalation (WHO, 2008). Anthrax outbreaks mainly occur after heavy rains and floods followed by a dry period or with the onset of rains ending a period of drought (Blackburn et al., 2007; Patassi 2016). These climatic conditions favor the concentration of spores in the upper level of the soil, increasing the risk of spore ingestion by herbivores. Climate change can also impact animal health in the Arctic region. The Anthrax outbreak that affected the reindeer population and humans in the Yamalo-Nenets region of Siberia in July 2016 is suspected to be associated with global warming and the abnormal warm temperatures observed in 2016, which may have substantially reduced the snow cover, water ice and permafrost in the area (FAO, 2017a). The previous reported outbreak in the area occurred in 1941, about 75 years ago. Time-series analyses of satellite-derived climate data over the past decades suggested that the observed changes in climate and livestock production system in the region may have increased animal exposure to Anthrax infected soil (FAO, 2017a).

Disease agents whose transmission depends primarily on close host-to-host contact can also be favored by extreme weather events that may increase contacts between naive and infected populations. For instance, prolonged droughts can increase the risk of occurrence of foot and mouth disease, hemorrhagic fevers, and tuberculosis (Abdela and Jilo, 2016).

Climate change has already been shown to determine a mismatch between migratory bird nesting and peak food abundance (Both et al., 2006) as well as changes in migration routes and timing (Hurlbert and Liang, 2012). The scarce availability of food during nesting is a great stressor that increases disease prevalence. At the same time, climate change may reduce available habitats, determining higher congregation of birds of several species in smaller areas of remaining resources and increasing the chance of within-species and cross-species disease transmission. Changes in migration routes and timing may also favor the emergence and introduction of a pathogen carried by birds in novel areas. This scenario is a likely explanation for the recent spread of highly pathogenic H5N8 avian influenza in Africa (FAO, 2017b).

Climate variability in rainfall, temperature, humidity patterns and extreme weather events, such as floods, droughts, heatwave, are therefore considered important indicators for monitoring and predicting animal diseases occurrence. As shown by the FAO Emergency Prevention System (EMPRES) since its implementation in 1994, early warning, early detection and early response are key in the prevention and control of both old and new emerging animal diseases (Lubroth, 2012). The FAO’s Global Surveillance and Early Warning System (GLEWS) actively tracks and verifies diseases rumors and disseminates confirmed disease outbreaks through the EMPRES-i Global Animal Disease Information System. FAO’S GLEWS conducts regularly risk assessments and modelling activities to provide decision makers in animal health and other stakeholders with guidance and recommendations on how to identify disease pathways, predict and prevent areas at risk of disease emergence and spread and implement rapid response and control measures on the ground. FAO’S GLEWS regularly monitors climatic and environmental risk factors using near-real time satellite-derived climate data. Using an algorithm developed by NASA and partners, a near-real time early warning system prototype for RVF has been developed using Google Earth Engine to identify and predict areas at risk of RVF vector amplification in East and West Africa (FAO, 2017). 

Preventive veterinary medicine, together with adjustment of animal husbandry and social resilience represents a way of coping with the negative consequences of climate change (Lubroth, 2012).

B2-1.3 Livestock production impact on climate change - need for mitigation of climate change

The livestock sector is a major contributor to climate change, generating significant emissions of carbon dioxide (CO2), methane and nitrous oxide. Livestock contribute to climate change by emitting greenhouse gases either directly (e.g. from enteric fermentation and manure management) or indirectly (e.g. from feed-production activities, the conversion of forest into pasture). Based on a life cycle assessment of the livestock sector, FAO estimates that it emits about 8.3 gigatonnes of CO2 equivalent (CO2 eq.) (GLEAM), distributed as follows. 

  • Land use and land-use change accounts for 0.7 gigatonnes of CO2 eq. per year (9 percent of the sector’s emissions). This figure refers to the carbon dioxide emitted from the replacement of forest and other natural vegetation by pasture and feed crops in Latin America and Soil Organic Carbon release (mineralization) from soils, such as pasture and arable land dedicated to feed production (see Box B7.3).
  • Feed production releases 2.6 gigatonnes CO2 eq. per year (33 percent of the sector’s emissions). It includes carbon dioxide emissions from fossil fuels used in manufacturing chemical fertilizer and pesticides for feed crops, and and nitrous dioxide emissions from chemical fertilizer application on feed crops (grasses and legumes. It does not include the carbon released by field operations (Soil Organic Carbon mineralization). 
  • livestock production releases 3.7 gigatonnes CO2 eq. per year (46 percent of the sector’s emissions), including from: enteric fermentation from ruminants (as methane) and on-farm fossil fuel use (in the form of carbon dioxide).
  • Manure management (mainly manure storage, application and deposition) accounts for 0.8 gigatonnes CO2 eq. per year (10 percent of the sector’s emissions) from methane and nitrous oxide.
  • Processing and international transport produces 0.23 gigatonnes CO2 eq. per year (3 percent of the sector’s emissions).

There are striking differences in global emission intensities among commodities. For example, on a global scale, the emission intensityvii  of meat and milk, measured by output weight, corresponds on average to 46.8 kg CO2 eq. per kg of carcass weight for beef; 72 kg CO2 eq. per kg of carcass weight for pork; 5.1 kg CO2 eq. per kg of carcass weight for chicken; and 2.9 kg CO2 eq. per kg of milk (FAO, 2013a and 2013b). Box B2.2 illustrates the case of substituting meat intake from livestock with low feed-conversion efficiency with livestock with higher feed-conversion efficiencyviii, such as insects.

There is significant variability in emissions across the different regions. For example, the FAO Life Cycle Assessment of greenhouse gas emissions from the global dairy sector estimated the global average at 3.0 kg CO2 eq. However it also found emissions per unit of milk products varied greatly among different regions. Emissions from Europe and North America range between 1.6 and 1.9 kg CO2 eq. per kg Fat and Protein Corrected Milk (FPCM). The highest emissions are estimated for sub-Saharan Africa with an average of 6.5 kg CO2 eq./kg of Fat and Protein Corrected Milk. Greenhouse gas emissions for Latin America and the Caribbean, Near East and North Africa and South Asia, range between 3.5 and 5.6 kg CO2 eq./kg Fat and Protein Corrected Milk (FAO, 2013a). 

Results from the same study of the global dairy sector also found greenhouse gas emissions to be inversely related to productivity. At very low levels of milk production (200 kg per cow per year) emissions were found to be 12 kg CO2 eq./kg FPCM compared to 1.1 kg CO2 eq./kg of Fat and Protein Corrected Milk for high production levels (about 8 000 kg of milk). This reflects the strong relationship between livestock intensification and greenhouse gas emissions across countries on a global scale (Gerber et al., 2011). This relationship is exponentially declining which means that small increases in productivity in the least intensive countries could provide the highest benefits in terms of emission intensity. 

However, beyond this strong relationship across countries, there is also a strong variability within countries, where production systems and management practices play an important role.

Box B2.2  Farming insects as 'minilivestock' 

The majority of insect collection occurs through wild gathering, mainly in forests. The concept of farming insects for food or feed is relatively new. 

Farming insects as “minilivestock” offers great opportunities to provide food at low environmental cost, without compromising wild insect populations and contributing positively to livelihoods in the context of climate change thanks to their high feed-conversion efficiency, relatively low greenhouse gas and ammonia emissions, and lower water requirements than cattle rearing. An example of rearing insects for human consumption in the tropics is cricket farming in the Lao People’s Democratic Republic, Thailand and Viet Nam.

Insects can supplement traditional feed sources, such as soy, maize, grains and fishmeal, to meet the increasing compund demand for feed production worldwide. Insects with the largest immediate potential for large-scale feed production are larvae of the black soldier fly, the common housefly and the yellow mealworm -but other insect species are also being investigated for this purpose. Producers in China, South Africa, Spain and the United States are already rearing large quantities of flies for aquaculture and poultry feed by bioconverting organic waste. 

FAO has commenced work on insect rearing for nutritional security in a technical manual on Edible insects: Future prospects for food and feed security.

                                                                                      Source: Sandra Corsi