Climate Change’s impact on Livestock
By Takudzwa Gondo
Global demand for livestock products is expected to double by the year 2050, mainly due to improvement in the worldwide standards of living and growing world population. Meanwhile, climate change is a threat to livestock production because of its negative impact on quality of feed crop and forage, water availability, animal and milk production, livestock diseases, animal reproduction, and biodiversity. The impacts of climate change on livestock production reduce livestock production and productivity. However, Livestock production also plays a part in the contribution to climate change therefore it’s important to prepare livestock farming to changing seasons through various adaptation and mitigation strategies.
Livestock contribute 14.5% of the total annual Greenhouse gas emissions globally. Livestock influence climate through land use change, feed production, animal production, manure, and processing and transport. Feed production and manure emit carbon dioxide, nitrous oxide and methane, which consequently affect climate change.
Livestock production will be greatly limited by climate variability as animal water consumption is expected to increase by a factor of three, demand for agricultural lands will increase due to need for 70% growth in production, and food security concern since about one-third of the global cereal harvest is used for livestock feed. The livestock sector will be a key player in the mitigation of emissions and improving global food security. Therefore, in the transition to sustainable livestock production, there is a need for preparing livestock production to new seasons through adaptation and mitigation measures, efficient livestock production systems and policies that support and facilitate the implementation of climate change adaptation and mitigation measures.
Climate change will also greatly impact on quantity and quality of livestock feeds. However, the impact will dependent on location, livestock system, and species. Some of the impacts on feed crops and forage are that the quality of feed crops and forage may be affected by increased temperatures. Climate change also results in extreme weather such as drought conditions and this will result in poor feed value nutritionally. Temperature increases may increase lignin and cell wall components in plants which reduce digestibility and feed utilization rates, leading to a decrease in nutrient availability for livestock. Extreme climate events such as floods and cyclones, may affect form and structure of roots, change leaf growth rate, and decrease total yields of fodder crops resulting feed shortages.
Global agriculture uses 70% of fresh water resources, making it the world’s largest consumer .However, global water demand is moving towards increased competition due to water scarcity and depletion, where 64% of the world’s population may live under water-stressful conditions by 2025.Water availability issues will influence the livestock sector, which uses water for animal drinking, feed crops, and product processes .The livestock sector accounts for about 8% of global human water use and an increase in temperature may increase animal water consumption by a factor of two to three .To address this issue, there is a need to produce crops and raise animals in livestock systems that demand less water or in locations with water abundance. For example, the growing of traditional grains which can thrive and still grow in areas with less water and include them in livestock diets.
The effects of climate change on livestock diseases depend on the geographical region, land use type, disease characteristics, and animal susceptibility. Animal health can be affected directly or indirectly by climate change, especially rising temperatures. The direct effects are related to the increase of temperature, which increases the potential for morbidity and death. The indirect effects are related to the impacts of climate change on microbial communities spreading of vector-borne diseases, food-borne diseases, host resistance, and feed and water scarcity. Climate change may induce shifts in disease spreading, outbreaks of severe disease, or even introduce new diseases. Global warming and changes in precipitation affect the quantity and spread of vector-borne pests such as flies, ticks, and mosquitoes.
Adaptation measures involve production and management system modifications, breeding strategies, institutional and policy changes, science and technology adoption, and changing farmers’ perception towards adaptive capacity. An adaptation such as the modification of production and management systems involves diversification of livestock animals and crops, integration of livestock systems with forestry and crop production, and changing the timing and locations of farm operations. Diversification of livestock and crop varieties can increase drought and heat wave tolerance, and may increase livestock production when animals are exposed to temperature stresses. In addition, this diversity of crops and livestock animals is effective in fighting against climate change-related diseases and pest outbreaks.
Agroforestry which is establishing trees alongside crops and pastures as a land management approach can help maintain the balance between agricultural production, environmental protection and carbon sequestration. Agroforestry may increase productivity and improve quality of air, soil, and water, biodiversity, pests and diseases, and improves nutrient cycling. Improving feeding practices as an adaptation measure could indirectly improve the efficiency of livestock production. Some of the suggested feeding practices include, modification of diets composition, changing feeding time and frequency, incorporating agroforestry species in the animal diet and training producers in production and conservation of feed for different agro-ecological zones .These practices can reduce the risk from climate change by promoting higher intake or compensating low feed consumption, reducing excessive heat load, decreasing the feed insecurity during dry seasons and reducing animal malnutrition and mortality.
Changes in breeding strategies can help animals increase their tolerance to heat stress and diseases and improve their reproduction and growth development. Good management of pastures is also essential for preparing livestock towards changing seasons. A beef sector study performed in Brazil estimated a reduction of up to 25% of greenhouse gas emissions related to grazing land use and land use change, accomplished by improving animal and herd efficiency. Pasture grass productivity and soil carbon sequestration could be improved by increasing grazing pressure in grasslands that have a lower number of grazing animals than their livestock carrying capacity
Enteric fermentation as a source of methane emissions can be reduced through practices such as improvement of animal nutrition and genetics. Examples of practices for mitigating enteric fermentation are increasing dietary fat content, providing higher quality forage, increasing protein content, providing supplements like feed antibiotics and the use of antimethanogens vaccines to suppress methane emissions. However, there is high uncertainty in the efficacy of these practices and high cost. In manure management most mitigation practices involve shortening storage duration, improving timing and application of manure, used of anaerobic digesters, covering the storage, using a solids separator, and changing the animal diets.
Climate change will affect livestock production and consequently food security. Livestock production will be negatively impacted due to diseases, water availability, etc. especially in arid and semiarid regions. In addition, climate change will affect the nutritional content of livestock products. Conversely, livestock production also influences climate change. Deforestation due to expansion of pasturelands and croplands for livestock production contributes to greenhouse gas emissions. To maintain or improve livestock production and productivity, it is essential to adopt various climate change adaptation and mitigation strategies. Adaptation strategies can improve the resilience of crop and livestock productivity to climate change. Mitigation measures could significantly reduce the impact of livestock on climate change. Adaptation and mitigation can make significant impacts if they become part of national and regional policies.