Climate Change Impact on Livestock: Adaptation and Mitigation

This chapter is divided into two parts. The first part covers three major topics: (1) greenhouse gas emission sources at the organisation level, (2) what GHG inventory is and its importance and (3) principles governing GHG accounting and carbon stock accounting. The second part will provide researchers with necessary information on technical issues relating to the significance of trees that we grow in our farms and any forest that exists. People in the world over don’t realise the importance of forests and therefore focus a lot on using timber, logs and wood fuel. The chapter takes through stages to quickly understand the gravity of science by applying mathematics. The reason is to quantify the carbon stocks that are sequestered over time. The basis will be understanding accounting and environmental science and their relationship with climate change. This provides the best solution to combat climate change.

Agriculture sector is a potential contributor to the total green house gas (GHG) emission with a share of about 24 % (IPCC, AR5 to be released) of the total anthropogenic emission, and a growing global population means that agricultural production will remain high if food demands are to be met. At the same time, there is a huge carbon sink potential in this sector including land use, land-use change, and forestry sector. For over four decades, evidence has been growing that the accumulation of GHGs in the upper atmosphere is leading to changes in climate, particularly increases in temperature. Average global surface temperature increased by 0.6 ± 0.2 °C over the twentieth century and is projected to rise by 0.3–2.5 °C in the next 50 years and 1.4–5.8 °C in the next century (IPCC, Climate change: synthesis report; summary for policymakers. Available: http://​www.​ipcc.​ch/​pdf/​assessment-report/​ar4/​syr/​ar4_​syr_​spm.​pdf, 2007). In the recent report of IPCC AR5 (yet to be released), it has been observed that warming will continue beyond 2100 under all representative concentration pathways (RCP) scenarios except RCP 2.6. Temperature increase is likely to exceed 1.5 °C relative to 1850–1900 for all RCP scenarios except RCP 2.6. It is likely to exceed 2 °C for RCP 6.0 and RCP 8.5 (Pachauri, Conclusions of the IPCC working group I fifth assessment report, AR4, SREX and SRREN, Warsaw, 11 November 2013). Agriculture is a potential source and sink to GHGs in the atmosphere. It is a source for three primary GHGs: CO₂, N₂O, and CH₄ and sink for atmospheric CO₂. The two broad anthropogenic sources of GHG emission from agriculture are the energy use in agriculture (manufacture and use of agricultural inputs and farm machinery) and the management of agricultural land. Mitigation methods to reduce emissions from this sector are thus required, along with identification and quantification of emission sources, so that the agricultural community can act and measure its progress. This chapter focuses on different sources of GHG emission from agriculture sector and their key mitigation strategies.

There is little doubt that climate change will have an impact on livestock performance in many regions and for most predictive models the impact will be detrimental. The real challenge is how do we mitigate and adapt livestock systems to a changing climate? Livestock production accounts for approximately 70 % of all agricultural land use, and livestock production systems occupy approximately 30 % of the world’s ice-free surface area. Globally 1.3 billion people are employed in the livestock (including poultry) sector and more than 600 million smallholders in the developing world rely on livestock for food and financial security. The impact of climate change on livestock production systems especially in developing countries is not known, and although there may be some benefits arising from climate change, however, most livestock producers will face serious problems. Climate change may manifest itself as rapid changes in climate in the short term (a couple of years) or more subtle changes over decades. The ability of livestock to adapt to a climatic change is dependent on a number of factors. Acute challenges are very different to chronic long-term challenges, and in addition animal responses to acute or chronic stress are also very different. The extents to which animals are able to adapt are primarily limited by physiological and genetic constraints. Animal adaptation then becomes an important issue when trying to understand animal responses. The focus of animal response should be on adaptation and management. Adaptation to prolonged stressors will most likely be accompanied by a production loss, and input costs may also increase. Increasing or maintaining current production levels in an increasingly hostile environment is not a sustainable option.

Climate change, and thermal stress (i.e., heat and cold) in particular, is a key limiting factor to efficient animal production and negatively impacts health and development during postnatal life. In addition, thermal stress (especially heat stress) during in utero development can permanently alter postnatal phenotypes and negatively affect future animal performance. The global effects of thermal stress on animal agriculture will likely increase as climate models predict more extreme weather patterns in most animal-producing areas. While the ultimate consequence of heat and cold stress is similar (reduced productivity and compromised animal welfare), their mechanism(s) of action substantially differs. Predictably, many of the metabolic and physiological effects of heat and cold stress are biologically contrasting; however, both are homeorhetically orchestrated to prioritize survival at the cost of agriculturally productive purposes. Consequently, thermal stress threatens global food security and this is especially apparent in developing countries. There is an urgent need for the scientific community to develop mitigation strategies to increase production of high-quality animal protein for human consumption during the warm summer months.

Water is an essential production factor in agriculture, both for crops and for livestock. Climate change will have a significant impact on agriculture in terms of affecting both water quantity and quality. It is known that changing climate will affect the water resource availability and global hydrological cycle. Livestock particularly in arid and semiarid region are mostly reared under extensive or traditional pastoral farming systems. The animals have different water requirements in different ambient temperatures. The requirement of water varies breed to breed according to their adaptability in a particular region and ambient temperature. Livestock of arid and semiarid region face the problem of water scarcity in most of the time of the year. So the animals need to take adaptive mechanism to overcome the water deprivation in different physiological stages. The animals exhibit several adaptive mechanisms to cope up to the less availability of water. These mechanisms include reduced plasma and urine volume, reduced faecal moisture, reduced body weight and reduced feed intake. The blood biochemical changes include increased haemoglobin, increased blood cholesterol and urea concentration, reduced protein concentration and increased sodium and potassium concentration. The endocrine changes include increased cortisol and reduced insulin, T₃, T₄ and leptin concentration in livestock. In addition, water deprivation in rumen also plays an important role in maintaining homeostasis in adapted animals. An adequate and safe water supply is essential for the normal and healthy production of livestock. Generally, surface or groundwater is supplied to the animals. This water source should be protected from microorganisms, chemicals and other pollutant contaminations. Keeping in view the adverse water scarcity predicted in the future, strategies have to be developed to improve water-use efficiency and conservation for diversified production system in different locations. More research is needed into water resources’ vulnerability to climate change and in order to support the development of adaptive strategies for agriculture.

Climate change has the potential to impact the quantity and reliability of forage production, quality of forage, water demand for cultivation of forage crops, as well as large-scale rangeland vegetation patterns. The most visible effect of climate change will be on the primary productivity of forage crops and rangelands. Developing countries are more vulnerable to climate change than developed countries because of the predominance of agriculture in their economies and their warmer baseline climates, besides their limited resources to adapt to newer technologies. In the coming decades, crops and forage plants will continue to be subjected to warmer temperatures, elevated carbon dioxide, as well as wildly fluctuating water availability due to changing precipitation patterns. The interplay among these factors will decide the actual impact on plant growth and yield. Elevated CO₂ levels are likely to promote dry matter production in C₃ plants more as compared to C₄ plants, and the quantum of response is dependent on the interactions among the nature of crop, soil moisture, and soil nutrient availability. Due to the wide fluctuations in distribution of rainfall in growing season in several regions of the world, the forage production will be greatly impacted. As the agricultural sector is the largest user of freshwater resources, the dwindling water supplies will adversely affect the forage crop production. With proper adaptation measures ably supported by suitable policies by the governments, it is possible to minimize the adverse impacts of climate change and ensure livestock productivity through optimum forage availability.

The first objective of this chapter is to review how climate change and climate variability may affect livestock diseases’ occurrences while emphasizing how little the knowledge on the links between livestock diseases and climate change is. The review of the literature shows that most of the investigated diseases are zoonotic ones with few specific to livestock and, moreover, these diseases appeared to be dramatically affected by climate variability rather than by ongoing climate change. A second objective of this chapter is to introduce some new modelling tools that can help predict diseases’ occurrences in space and in time in relation to climate variability and change, namely, environmental niche modelling, epidemiological modelling using R₀ map and teleconnection modelling. A working example on cattle trypanosomiasis in China is given to illustrate teleconnection modelling by using data from the World Organization for Animal Health (OIE). The conclusion of this chapter stresses three points: the need to consider the entangled linkages between ecosystems, society and health of animals and humans; the need of elaborated scenarios of livestock diseases linked to climate change and variability, which necessitates to develop and improve the recording of livestock diseases; and the need to incorporate climate-mediated physiological responses into the programs that manage breeding genetic diversity.

In the current scenario, climate change is occurring all over the world, which directly or indirectly affecting the agricultural production as well as the production of livestock. The arid and semiarid region of the world, where more than 75 % population of livestock exists, will be going to have pronounced effect of climatic change. Amongst the other stresses, heat stress is the most vital climatic stress which drastically affects the productive potential of livestock, and sometimes it is lethal to animal survival in harsh conditions. High ambient temperature, air movement, solar radiation, wind speed and relative humidity are important attributes of the climatic variables. Amongst the above-mentioned variables, high temperature, radiation and humidity are the most important factors, which drastically affect the overall performance of livestock with substantial reduction in meat, milk and egg production. In this context, the chapter highlights the significance of studying the impact of multiple stresses impacting livestock production simultaneously. The different adaptive means by which livestock respond to fluctuation of climatic changes are physiological, blood-biochemical, neuroendocrine, cellular and molecular mechanisms, respectively. In present climate change scenario, several mitigation strategies are to be implemented by which the production of livestock may be sustained to an extent even in harsh climatic conditions.

This chapter provides an overview of the current state of knowledge concerning global warming with special reference to contribution from livestock resources. Global warming pertains to the effect of natural greenhouse gases (GHGs) such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and halogenated compounds on the environment. These GHGs are generated by humans and human-related activities. Carbon dioxide, CH₄, and N₂O are the principal sources of radiative forcing (Fifth IPCC Report of 2013). Interestingly, livestock contributes to climate change through emissions of CO₂, CH₄, and N₂O into the atmosphere. Globally, the livestock sector directly and indirectly contributes 18 % (7.1 billion tonnes CO₂ equivalent) of GHG emissions. While direct GHG emissions from livestock refer to emissions from enteric fermentations in livestock, urine excretion, and microbial activities in manures, indirect GHG emissions are those not directly derived from livestock activities but from manure applications on farm crops, production of fertilizer for growing crops used for animal feed production, and processing and transportation of refrigerated livestock products. Other indirect emissions include deforestation, desertification, and release of carbons from cultivated soils due to expansion of livestock husbandry. According to FAO’s Global Livestock Environmental Assessment Model (GLEAM), the GHG emission from livestock-related activities was estimated to be around 7.1 gigatonnes CO₂-eq. per annum, representing 14.5 % of human-induced emissions. This clearly indicates the significant role for livestock contributions to climate change.

Rumen fermentation of carbohydrates plays a fundamental role in ruminant metabolism as the main source of energy. Acetic, propionic and butyric acids (namely, volatile fatty acids, VFA) are the main products of the rumen fermentation of structural and nonstructural carbohydrates contained in the ruminant’s diet. The metabolic pathways involved in VFA production are strictly linked to methane emission, because hydrogen is actively produced during the fermentation of structural carbohydrates, and it is rapidly metabolised by methanogens, in order to maintain the optimal thermodynamic condition for the metabolism of the microbe consortium in the rumen. Hydrogen plays also a fundamental role in the maintenance of the equilibrium among VFA pathways and in their interconversion. In this chapter, after a brief chemical description of dietary carbohydrates, individual VFA pathways are described in order to put in evidence the thermodynamic control points of each pathway and the production of energy and reductive equivalent. Then, the relationship between hydrogen, VFA and methane production has been reviewed, considering the role of some dietary factors, the substrate competition between different metabolic pathways and the models of VFA estimation.

Methane is a potent greenhouse gas (GHG) which is responsible for global warming, and it is about 23 times more potent than carbon dioxide and is produced worldwide by biotic and anthropogenic activity. Increased industrialisation in the past few decades and an increase in global human population have increased the demand of food particularly of animal origin to a significant level. The livestock population, especially ruminants in particular, is responsible for emitting 16–20 % of the CH₄ to the atmosphere. The enteric fermentation in ruminants is unique, carried out by the anaerobic microorganism, and culminates in the formation of CH₄, which is the sink for hydrogen and carbon dioxide, formed as a result of anaerobic fermentation in the rumen. The population of domesticated ruminant livestock species like cattle, buffalos, sheep, goat, mithun, yak, etc., which provide food to humans has increased worldwide in the recent past. These livestock are reared under different systems that are prevailing in a particular country, and the most common identified livestock rearing systems are intensive, extensive and semi-intensive. In intensive system of rearing, the animals are confined and more concentrates are fed with provision of quality roughages. While in the extensive system of rearing, the livestock are let loose and depend on the pasture for their growth and production, and the quality of the pasture is responsible for the nutrients assimilated by the animal. The semi-intensive system of rearing is a combination of the above two systems. Enteric CH₄ production in ruminants depends on several factors like type and quality of feed, the physical and chemical characteristics of the feed, species of livestock, feeding level and schedule, the efficiency of feed conversion to livestock products, the use of feed additives to support production efficiency, the activity and health of the animal and genetic make-up of the animal. Therefore, feeding system(s) employed for livestock rearing certainly has an effect on the enteric CH₄ production. A concerted effort has been put in this chapter to get an insight into the different livestock rearing and feeding systems, CH₄ contribution from livestock and global warming, CH₄ production from different feeding systems and means to augment livestock production by reducing enteric CH₄ under different feeding regimens.

As enteric methane emissions from ruminants contribute to feed inefficiency and global warming, methodologies to measure the enteric methane from either the individual ruminant or the herd are needed. Therefore, methane emission estimations in ruminants may provide insight into potential methane mitigation strategies. Furthermore, the use of methane emission methodologies enables researchers to compare and contrast methane emissions from different diets, breeds, and geographical locations and to evaluate mitigation strategies. This chapter describes key methane estimation methodologies previously and currently used in research and highlights the advantages and disadvantages of each methodology. Key in vivo techniques include open- and closed-circuit respiration chambers, open-circuit hood systems, sulfur hexafluoride (SF₆) tracer, polythene tunnel system, methane/carbon dioxide ratio, GreenFeed, infrared (IR) thermography, laser methane detector, and the intraruminal gas measurement device. Furthermore, the in vitro gas technique (IVGT) estimates the methane emissions from different dairy rations. Theoretical methodologies include the rumen fermentation balance, COWPOLL ruminant digestion model, and the Cattle Enteric Fermentation Model (CEFM). Although there are several different types of methane estimation methodologies, the cost, species, accuracy of the technique, maintenance, and the environment of the ruminant are all contributing factors in choosing which technique to apply to a study.

Livestock production in developing countries is subsidiary to plant agriculture. In tropical countries, ruminants are fed on lignocellulosic by-products like cereal straws, tree foliages, and cakes of oilseeds. The rumen harbors complex microbial communities which play a critical role in efficient utilization of such complex plant materials. The metagenome of the rumen is considered a determining factor for the efficiency of the particular digestive metabolism of ruminants as well as the accompanying environmental problems. Gene signature and biological fingerprinting of microorganisms present in ruminants is an important area of scientific research. Recent advances in the ruminant gut microbiology and genomics now offer new opportunities to conduct a more holistic examination of the structure and function of rumen ecology. The importance of rumen microbial signature and diversity of microorganisms in the ruminant forestomach has gained increasing attention in response to recent trends in global livestock production. Applied metagenomics has the potential for providing insight into the functional dynamics of the ruminomics database and will help to achieve a major goal of rumen ecosystem; microbial communities function and interact among these microbes as well as with the host. In this book chapter, we highlight recent studies of the buffalo rumen microbiome in rumen ecology, nutrition, animal efficiency, and microbial function.

Livestock are important source of GHG emissions accounting for about 28 % of the global anthropogenic methane emissions. The participation of this sector in the carbon markets is, however, in nascent stage, largely confined to animal waste management projects, although the emissions from enteric fermentation are several times more than that from manure. This chapter discusses the potential of generating carbon credits by improving the feed fermentation efficiency through nutritional interventions such as dietary manipulation and feed additives and increasing the productivity of animals through breeding and other long-term management strategies. There are several socioeconomic, institutional, and technical challenges for the stakeholders in successful formulation and implementation of such mitigation options from the perspective of carbon trading. As the global carbon trading system in one form or the other will be a fixture in the world economy for decades, it is imperative that the uptake of programmatic approaches to project development is increased and standardized approaches to baseline, additionality assessment, and activity-based monitoring methods underpinned by regionally specific field research are developed.

Rumen has a complex consortium of microorganisms comprising of bacteria, protozoa, fungi, archaea and bacteriophages, which synergistically act upon the lignocellulosic feeds consisting of cereal straws and stovers, green forages and hays, oil cakes, etc., and produce a mixture of short-chain volatile fatty acids and microbial proteins which the animals can use as a source of nutrients. During this bioconversion process, hydrogen is generated in large quantities which combine with carbon dioxide to generate methane by the activity of methanogenic archaea. Depending upon the composition of diet, the animals might lose 5–12 % of gross energy intake in the form of methane, which leads to poor feed conversion efficiency. To avoid this loss of energy in the form of methane, several methods are technically available (e.g. methane analogues, inorganic terminal electron acceptors, ionophore antibiotics, organic unsaturated fatty acids, microbial intervention like use of probiotics and selective removal of ciliate protozoa and plant secondary metabolites), but each one of them has its own merits and demerits. In many cases, the results are based upon only in in vitro experiments. In this chapter, a few of the feed supplements which have a potential to inhibit methanogenesis and have been tested in in vivo experiments will be discussed.

Methane is produced from the anaerobic fermentation in ruminants as a pathway for the disposal of metabolic hydrogen produced during microbial metabolism. This methane is not only related to environmental problems but also is associated with energy losses to the tune of 8–12 % of ingested gross energy. In addition, methane is 23 times more potent as CO₂ in global warming, and its emissions from enteric fermentation and manure management cause 24 and 8 % of total methane emissions from anthropogenic activities, respectively. The increasing accumulation of CH₄ in the atmosphere has necessitated investigation on newer strategies of manipulating the rumen ecosystem to ameliorate methane emission. Various strategies have been developed to reduce ruminal methanogenesis by means of chemical and biotechnological means and by nutritional management. The use of concentrate to ameliorate methane emissions from livestock is practically difficult in many parts of the world including India due to the high price of cereals and their competition with human food. There are many naturally occurring compounds that appear to have anti-methanogenic properties, such as tannins, saponins, and essential oils. Researchers are actively engaged in evaluating the potential of these secondary plant constituents as natural means of modifying ruminal fermentation.

Imbalanced feeding is widely prevalent in the smallholder dairy systems of tropical countries. Dairy animals fed on imbalanced rations not only produce less milk at a higher cost but also produce more methane per unit of milk production. As imbalanced feeding adversely impacts livestock productivity, health and the environment, it is a need of the hour to implement a practical and cost-effective approach for improving productivity and reducing methanogenesis in tropical ruminants. Changing plane of nutrition through balanced feeding has improved feed conversion efficiency, milk production and microbial protein synthesis and reduced methane emissions in cows and buffaloes, under field conditions. Balanced feeding might have resulted in a shift in volatile fatty acid pattern towards more propionate and less acetate, resulting in lower methane production. Thus, ration balancing could be a practical approach for reducing methanogenesis in tropical feeding systems.

Greenhouse gas (GHG) emissions from livestock is about 7,516 million metric tons CO₂₋eq. year⁻¹ and has multiple components that include enteric methane emissions, methane and nitrous oxide emissions from manure and carbon dioxide emissions associated with feed production and grazing. An uninterruptedly increasing concentration (155 % more than preindustrial level), a comparatively high global warming potential and a short half-life of methane make it a bit more important than any other GHG in the control of global warming and climate change. Enteric methane mitigation is not only important from a global warming point but also for saving animal dietary energy which is otherwise lost in the form of methane. Due to the central regulatory role of H₂, it is generally referred as the currency of fermentation and most of the mitigation strategies revolve around its production or disposal in such a way as to ensure the conservation of energy into desirable end products. In the chapter, an attempt is made to address the prospects of some emerging approaches to redirect metabolic H₂ away from methanogenesis and serve as potential alternate sink for H₂ in the rumen for conserving energy. The prospects of alternate sinks, for instance, sulphate and nitrate reduction and reductive acetogenesis and propionogenesis, are debated in the chapter along with the anticipated benefits that can be achieved from the practically feasible 20 % enteric methane reduction.

This study focuses on greenhouse gas (GHG) emission from livestock manure. In addition to the global warming potential of the GHGs (e.g., CH₄, N₂O, NO, CO₂), ammonia (NH₃) emissions contribute to global warming when NH₃ is converted to nitrous oxide (N₂O). Therefore, this chapter addresses in detail the GHG and NH₃ emissions from livestock manure and their mitigation strategies. This chapter illustrates several mitigation strategies for reducing emissions from manure management continuum, for example, manure storage abatement techniques, use of additives, manipulation of manure pH, implementation of inhibitors, anaerobic treatment, thermochemical conversion of manure, and implementation mitigation policies (e.g., emission tax, emission cap, livestock extensification). Additionally, several innovative mitigation strategies were discussed, for instance, manure treatment methods to produce value-added products and bioenergy and abate emissions, the biorefinery approach, and life cycle analysis to improve the productivity and use of resources and abate emissions.

The total global GHG emission from agriculture, considering all direct and indirect emissions, is between 17 % and 32 % of the total human-induced GHG emissions, including land use changes. It is estimated that livestock production is responsible for 15–24 % of GHG emissions. Cattle, pigs and poultry are the major world livestock, and European countries have one of the highest livestock densities in the world. The dairy cow and beef cattle sectors are the largest sources of agriculture GHG emissions, with CH₄ from enteric fermentation and N₂O from agricultural soils being the most important. However, agriculture could contribute significantly to GHG emission mitigation. In the EU, livestock farming contributes approximately 10 % of the total global GHG emissions. The European livestock sector is expected to remain dynamic in the forthcoming years. The possibility of predicting and modelling emissions from livestock farm GHGs is important due to the increasingly restrictive European standards. This chapter presents various modelling approaches to predict livestock’s contribution to GHG emissions in the EU.

Livestock production is thought to be adversely affected by detrimental effects of extreme climatic conditions. Consequently, adaptation, mitigation and amelioration of detrimental effects of extreme climates have played a major role in combating the climatic impact in livestock production. While measures to reduce the growth of greenhouse gas emissions are an important response to the threat of climate change, adaptation to climate change will also form a necessary part of the response. The salient adaptation strategies are developing less sensitive breeds, improving water availability, improving animal health, promoting women empowerment, developing various policy issues, establishing early warning systems and developing suitable capacity building programmes for different stakeholders. Developing adaptation strategies is therefore an important part of ensuring that countries are well prepared to deal with any negative impacts that may occur as a result of climate change. The integration of new technologies into the research and technology transfer systems potentially offers many opportunities to further the development of climate change adaptation strategies. Adapting to climate change and reducing GHG emissions may require significant changes in production technology and farming systems that could affect productivity. Many viable opportunities exist for reducing CH₄ emissions from enteric fermentation in ruminant animals and from livestock manure management facilities. To be considered viable, these emission reduction strategies must be consistent with the continued economic viability of the producer and must accommodate cultural factors that affect livestock ownership and management. This chapter also elaborates on ameliorative strategies that should be given consideration to prevent economic losses incurred due to environmental stresses on livestock productivity. Reducing the impact of climatic stresses on livestock production requires multidisciplinary approaches which emphasise animal nutrition, housing and animal health. Therefore, emphasis should be given to all three aspects of adaptation, mitigation and amelioration strategies to sustain livestock production under the changing climate scenario.

Shelter design of different livestock needs suitable modifications to prevail climate change infliction. Thermal stress alleviation, methane mitigation and optimisation of space requirements are major shelter design considerations for livestock in the climate change scenario. In this perspective, the chapter deals with considerations and some suggested modifications in flooring, roofing, heat stress alleviation and waste management and disease prevention aspects of housing of different livestock. In cattle barns, the thermal conductivity of floor, ventilation aspects and other thermal properties of different roofs and roofing materials, temperature humidity index (THI)-based wetting and other important thermal stress alleviation techniques and measures to reduce methane emission through proper waste management are relevant in the context. In pigsties, flooring, roof, thermal stress aspect, disease prevention and waste management aspects need careful considerations. Proper designing of goat units not only averts production loss but also optimises space utilisation and prevents diseases ensuring maximum production. Rabbit and poultry are highly susceptible to stress, especially due to climatic variations, and the success of rabbit and poultry farming mostly depends on congenial macro- and micro-environments and the effectiveness of the ameliorating measures taken to reduce the stress factors. The integration of different livestock through suitable designs will ensure food security, reduce stress and help in carbon recycling. Innovative, integrated and self-sufficient shelter designs for climate change adaption of animal agriculture can be achieved through multidisciplinary approach.

Global diversity of livestock in the form of many different species and breeds in a variety of production environments is indicative of the fact that it has developed over time in sync with the ecosystem. The developing world is particularly enriched with livestock breed portfolio. Natural selection has mainly acted on fitness including adaptability and reproductive success, whereas selection practised by livestock keepers and animal breeders has been need based. As against highly structured breeding programmes and intensive selection in developed world, livestock of developing world have largely been subjected to differential selection pressures in the form of their ability to survive in harsh production environments and challenged inputs. The last few decades have witnessed large-scale erosion of livestock genetic diversity. Climate change (CC) through its direct and indirect effects including its mitigation measures is believed to have influenced the erosion. Faster loss of animal genetic diversity poses greatest threat to the sustainability of the sector. The presence of varied livestock species and their breeds with widely variable performances offers the opportunity for genetic improvement. In the absence of it, we risk progress in this sector. Reorientation of livestock breeding is required to address the issues of CC. Although resource-use efficiency is imperative, careful trade-off between livestock production, productivity and adaptability will be required. Breeding strategies for livestock genetic resources to counter CC impact will not be fundamentally different in the future. Natural stratification of species and breeds of livestock shall be an important guide in the design. Appropriate policy framework, large-scale cooperation in knowledge and resources and awareness will be crucial.

Climate change and climate change mitigation will bring about major structural change in the agriculture, forestry, and other land use sectors. With effective global action, climate change mitigation would become the more important force for change. In agricultural and animal production, to control and decrease emission of harmful greenhouse gases (GHGs) have become important in environmental protection. The contributions to global warming by ruminant livestock are by and large through enteric CH₄ production. Hence while aiming at sustainable livestock production, it is imperative to concentrate on reduction strategies for enteric methane production. The enteric methane emission reduction strategies can be grouped under three broader headings including management, nutritional, and other molecular strategies. The application of a single strategy would not help and may need a combination of strategies to address mitigation based on the agroecosystems, the production systems, and the resources available with the farmer. While measures to reduce the growth of GHG emissions are an important response to the threat of climate change, adaptation to climate change in addition to mitigation will also form a necessary part of the response. Promotion of sustainable livestock production will be vital to ensure that the impact of climate change is minimized on the livestock farmers. This will involve rearing of animals which are more sturdy, heat tolerant, disease resistant, and relatively adaptable to the adverse climatic stress conditions. Livestock has potential to strengthen resilience to climate change, as livestock production systems tend to be more resilient than crop-based systems. In developing a strategy for adapting to climate change, one key challenge is dealing with uncertainty. The challenge for governments and agricultural industry stakeholders is to deal with these uncertainties through further research and the development of policies and farm management approaches that are flexible enough to deal effectively with a range of potential climate change outcomes.

Given that the livestock production system is sensitive to climate change and at the same time itself a contributor to the phenomenon, climate change has the potential to be an increasingly formidable challenge to the development of the livestock sector in the world. This chapter provides the salient findings established by various researchers in their field of specialization and also elaborates on the future research priorities that are available before the researchers in the field of climate change and livestock production. In the changing climatic scenario, apart from high ambient temperature, air movement, solar radiation, wind speed, and relative humidity are other critical attributes of the climatic variables that hamper livestock production. The direct effects on livestock production are primarily mediated through increased temperature, altered photoperiod, and changes in rainfall pattern. The indirect effects on livestock production are mediated through sudden disease outbreaks, less feed and water availability, and low grazing lands. There are different adaptive mechanisms by which livestock respond to fluctuations of climatic changes including physiological, blood biochemical, neuroendocrine, cellular, and molecular mechanisms of adaptation, respectively. Globally, the livestock sector contributes 18 % of global GHG emissions. Hence, understanding of GHG emissions by sources and removal by sinks in animal agriculture is critical to take appropriate mitigation and adaptation strategies and to estimate and develop inventory of GHGs. The chapter also signifies that considerable research efforts are needed to modify the existing shelter design to make them more suitable for the current climate change scenario. The chapter also calls for multidisciplinary approach to develop suitable technological interventions to cope up to climate change for the ultimate benefit of livestock farmers who rely heavily on livestock resources for their livelihood security. If one attempts improving livestock production under the changing climate condition, research efforts are needed to develop strategies encompassing adaptation, mitigation, and amelioration strategies simultaneously, apart from strengthening the existing extension system.