Prof. Dr. R.N.Sreenivas Gowda*
Introduction
Public are facing unusual rise in global temperatures this year, even many cities are facing acute shortage of water , but it was different in the year 2022 and 2023 where there was heavy rains and floods in many parts of our country. The experts are of the opinion that it is due to climate change in recent years, the livestock is also no exception, hence this paper to find the effect of global warming and climate change on livestock.
Climate affects livestock growth rates, milk and egg production, reproductive performance, morbidity, and mortality, along with feed supply. Simultaneously, livestock is a climate change driver, generating 14.5% of total anthropogenic Greenhouse Gas (GHG) emissions.
Climate change is the complex and multidisciplinary change in global or regional climate patterns, which pose a significant risk for human and natural systems, it is similarly threaten livestock production and productive performance. The climate change is primarily due to an increase of global atmospheric temperature and greenhouse gases mostly carbon dioxide (CO2) concentration, precipitation variation, and/or permutation of these factors (Henry et al., 2012). The distribution of infectious diseases, (human, animal and plant) and the timing and intensity of disease outbreaks are often closely linked to climate. Climate change may affect livestock disease through several pathways.Climate change impacts livestock directly (for example through heat stress and increased morbidity and mortality) and indirectly (for example through quality and availability of feed and forages, and animal diseases).
Definitions
Global warming is the slow increase in the average temperature of the earth’s atmosphere because an increased amount of the energy (heat) striking the earth from the sun is being trapped in the atmosphere and not radiated out into space. Increase of 1o C will cause significant changes in the environment. Changes in temperature, rainfall patterns, and other environmental factors are affecting the habitats, migration patterns, and populations of many species. As a result, wildlife is facing numerous threats, from habitat loss and fragmentation to species decline and extinction.
Climate change is an association of multidimensional effects on climate including physical characteristics, causes, and consequences (Visschers, 2018). Climate change is defined as an average weather condition of an area that is characterized by its own internal dynamics, and it can affect by changing its external factors. The United Nations Framework Convention on Climate Change (UNFCC) defines climate change as the change resulting from long-term direct and indirect activities that induce changes in the compared time, which are much more than the natural change (UNFCCC, 1992).
Factors responsible for climate change and global warming
Burning fossil fuels, cutting down forests and farming livestock are increasingly influencing the climate and the earth’s temperature. The main driver of climate change is the greenhouse effect. Some gases in the Earth’s atmosphere act a bit like the glass in a greenhouse, trapping the sun’s heat and stopping it from leaking back into space and causing global warming. The most common greenhouse gases (GHG) covered under the Kyoto Protocol are:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulphur hexafluoride (SF6)
- Nitrogen trifluoride (NF3)
Effect of global warming are:
- Disappearing glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages
- Rising sea levels will lead to even more coastal flooding
- Depletion of forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and continue to increase the risk of wildfires.
- Increased rains and flooding. All of these can damage or destroy agriculture and fisheries.
- Disruption of habitats such as coral reefs, mountains, medows and forests could drive many plant and animal species to extinction.
- Increase in Allergies, asthma, and infectious disease outbreaks will become more common due to higher levels of air pollution, and the spread of conditions favorable to pathogens and mosquitoes.
Impact on animal health
Climate change will have many knock-on effects on production both directly and indirectly, and are all depicted in the fig1.
Fig1. Impact of climate change on Livestock Production and health
( Source: Sejian, V et,al (2016),Feedifedia)
The direct effect of climate change on livestock health includes temperature related to frequent disease incidence and death. The indirect effect follows more intricate pathways and includes the climate influences on pathogen density and distribution and multiplication of vectors as well as vector-borne diseases and soil-, food-, and water-borne diseases. The climate change on livestock could cause both direct and indirect effects (Table 1 &2,Fig1.).
The direct effects of climate on animal disease are likely to be most pronounced for diseases that are vector- borne, soil associated, water or flood associated, rodent associated, or air temperature/humidity associated and sensitive to climate (Grace et al., 2015).
Table 1, Direct effect of climate change on livestock
| Sl no | Cause | Effect |
| 1 | Heat stress | increased body temperature and respiration rates.Decrease in feed intake and milk production |
| 2 | Metabolic disorders | KetosisLameness |
| 3 | Oxidative stress | Decrease in serum antioxidant levels Reduction of carotenes and Vitamin E levels.increased activity of antioxidant enzymes such as superoxide glutathione, dismutase, and catalase peroxidase.ROS such as hydrogen peroxide (H2O2), superoxide anions (O2−), and hydroxyl radicals (OH-) have a negative impact on lipid peroxidation, and the enzyme inactivation process causes cell damage |
| 4 | Immuno- suppression | Impair immune response in poultry.reduced colostrum immunoglobulins such as IgG and IgA in dairy cows.Depression in lymphocyte function that hampers the efficacy of vaccinations.Impaired function of neutrophils that are important for defense against bacteria.High prevalence of the resistance of bacteria to most antibiotics.Increase in mastitis incidence |
| 5 | Effect on production | Alters the production of different hormones.Increased incidence of post-partum anoestrus in cattle. Decrease in milk productionSeasonal infertility and Impaired reproductive disturbances in pigs.Impacts semen quality, oestrus cycle and oocyst and embryo development . |
| 6 | Mortality | increased mortality incidence in all species of animals during extreme weather situation |
In most cases, the impact of heat stress is reduced productivity and animal welfare. However, under severe or prolonged conditions, mortalities will also occur. Reduced feed intake is one of the first and biggest consequences of heat stress, leading to declines in growth rates and production of milk or eggs.
Table 2. Indirect effect of climate change
| Cause | Effect | |
| 1 | Vectors | Increase in vector-borne pests such as midges, flies, ticks, and mosquitoes and positively affect the spatial distribution of vectors. |
| 2 | Vector-borne diseases | increase the geographic spread of vector-borne diseases such as bluetongue, lumpy skin diseases (LSDs), anaplasmosis, babesiosis, and theileriosis. |
| 3 | Hemoprotozoan infections | Increase protozoal infections such as Babesia spp., Anaplasma spp., and Theileria spp. cause health hazard of livestock in tropical countries. |
| 4 | Parasites and Helminths | Increase in Haemonchus contortus in the tropical regions Ascaris suum eggs through enhanced embryonation becomes accelerated when ambient temperature increases.Influence the rapid development of parasites in their invertebrate intermediate hosts like snails.lifecycle of lungworms is also increases the incidence in the summer/autumn than the winter season.Increase in the activity of Fascioliasis, schistosomiasis, and nematodiases including heterakiasis and different trichostrongyliases. |
| 5 | Other pathogens | Increase in black quarter, dermatophiloses, and anthrax. |
| 6 | Mycotoxins | The major mycotoxins Produced in adverse climate change are: aflatoxin, ochratoxin, T2, fumonisin, and zearalenone, which are a metabolic product of mycotoxicogenic molds produced at the optimum temperature of 25°C–37°C and humidity of 80%–85%.Aflatoxin type B1 is more toxic and has a significant public health impact due to hepatotoxic and its carcinogenic properties in humans. |
Climate change contribute to an increase in disease spread for livestock such as ovine chlamydiosis, caprine arthritis (CAE), equine infectious anemia (EIA), equine influenza, Marek’s disease (MD), and bovine viral diarrhea. There are many rapidly emerging diseases that continue to spread over large areas. Outbreaks of diseases such as foot and mouth disease or avian influenza affect very large numbers of animals
Implications
- The livestock sector requires a significant amount of natural resources and has an important role in global greenhouse gas emissions. The most important greenhouse gases from animal agriculture are methane and nitrous oxide.
- Mitigation strategies aimed at reducing the emission intensity of this sector are needed to meet the increasing demand for livestock products driven by population growth.
- To increase the effectiveness of mitigation strategies, the complex interactions among the components of livestock production systems must be taken into account to avoid environmental trade-of
Conclusion
Climate change is now a global concern due to its multidimensional effects and impact on humans, animals, plants, and environment. Research has established that changes in global or regional climate patterns due to climate change are affecting livestock health directly and indirectly. Changes in management, technologies and infrastructure may be necessary to ensure animal production is resilient to climate change effects. The appropriate means of adaption will be dependent on the location, sector and production system. A proactive approach is key to the management of climate risks.
Reference:
- Grace, D., Bett, B., Lindahl, J., & Robinson, T. (2015). Climate and Livestock Disease: assessing the vulnerability of agricultural systems to livestock pests under climate change scenarios. CCAFS Working Paper No. 116. Copenhagen, Denmark: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).
- Henry B, Charmley E, Eckard R, Gaughan J.B, Hegarty R. Livestock production in a changing climate: adaptation and mitigation research in Australia. Crop Pasture Sci. 2012;63:191–202. [Google Scholar]
Sejian, V., Gaughan, J. B.2, Raghavendra Bhatta and Naqvi, S. M. K.(2016) Impact of climate change on livestock productivity. Feedipedia
- Visschers V.H. Public perception of uncertainties within climate change science. Risk Anal. 2018;38:43–55. [PubMed] [Google Scholar]
- UNFCCC. Definitions of climate change. [23 September 2019];1992 7 Available via http://unfccc.int/files/essential_background/background_publications_htmlpdf/application/pdf/conveng.pdf . [Google Scholar]
(*Author: Former and founder Vice-chancellor, KVAFSU, Bidar, Former Director IAH&VB, Bangalore, Former Prof &University Head dept. of Pathology, Veterinary College, UAS, Bangalore)