Poultry farming, climate change, and drivers of antimicrobial resistance in India

The need to apply a systems approach to planetary health is well recognised.1The Lancet Planetary HealthWelcome to The Lancet Planetary Health.Lancet Planet Health. 2017; 1: e1Summary Full Text Full Text PDF PubMed Scopus (14) Google Scholar Such an approach has enabled a better understanding of the links between factors such as climate change, ecosystem conditions, and marine conservation efforts on fisheries sustainability,2Lombard AT Dorrington RA Reed JR et al.Key challenges in advancing an ecosystem-based approach to marine spatial planning under economic growth imperatives.Front Mar Sci. 2019; 6: 1-11Crossref Scopus (17) Google Scholar and between heat stress, water shortages, food availability, and the health of people older than 65 years.3Stevenson M Thompson J Health and the compact city.in: Decarbonising the built environment. Palgrave Macmillan, Singapore2019: 245-258Crossref Google Scholar Fieldwork in India to investigate poultry practices that drive antibiotic resistance shows that by keeping a systems approach in mind one can get closer to the root cause of challenges. These challenges might run far deeper than initial observations and assumptions make visible. Across the world, high use of antibiotics in livestock and poultry production is most often attributed to low compliance with regulation and poor antimicrobial stewardship.4Laxminarayan R Chaudhury RR Antibiotic resistance in India: drivers and opportunities for action.PLoS Med. 2016; 13e1001974Crossref PubMed Scopus (271) Google Scholar The long-term harm from antibiotic resistance is often overlooked when compared with the benefits of antibiotic use, particularly as the costs associated with antimicrobial resistance in human health are an externality to the farming industry.5Giubilini A Birkl P Douglas T Savulescu J Maslen H Taxing meat: taking responsibility for one's contribution to antibiotic resistance.J Agric Environ Ethics. 2017; 30: 179-198Crossref Scopus (12) Google Scholar Changing use patterns requires system-wide adaptation, including acceptance of alternatives to antibiotic growth promoters (APGs), increased vaccination, and improved natural immunity. The latter could in turn depend on better farm hygiene and welfare conditions to reduce infection and thus the need for treatment. The impact of higher temperatures on poultry growth rates and egg production is acknowledged,6Nyoni NM Grab S Archer ER Heat stress and chickens: climate risk effects on rural poultry farming in low-income countries.Clim Dev. 2019; 11: 83-90Crossref Scopus (36) Google Scholar but climate pressures on poultry farming can influence many of the aforementioned approaches to poultry health and disease control. In the rural areas around Bangalore, farmers are increasingly moving from crop production to poultry rearing as water shortages and higher temperatures hamper crop productivity and reduce the reliability of crops as a regular source of income.7Kattumuri R Ravindranath D Esteves T Local adaptation strategies in semi-arid regions: study of two villages in Karnataka, India.Clim Dev. 2017; 9: 36-49Crossref Scopus (29) Google Scholar Since 2018, this has been exacerbated by an epidemic of Spodoptera frugiperda (Fall armyworm), an invasive parasite that was brought into India with American maize that is resilient to hot, dry conditions and became a popular local crop. Fall armyworm has attacked other crops, including sugarcane and chickpea, as well as maize. Poultry production is less water-intensive than crop farming and provides a more reliable year-round income, but requires more antibiotic input to address disease challenges. An increase in poultry farming at a time of increasing local average temperature (predicted to rise between 1·8°C and 3·3°C in Karnataka by 2030 with respect to the baseline period 1961–908Murari KK Mahato S Jayaraman T Swaminathan M Extreme temperatures and crop yields in Karnataka, India.Rev Agrarian Stud. 2018; 8: 92-114Google Scholar) is likely to result in increasing incidences of heat stress-related morbidity. Heat stress drives antibiotic use not only by causing immune system compromise and leaving broiler chickens more susceptible to bacterial infection, but also by causing symptoms such as decreased appetite and diarrhoea that might be mistaken, particularly by less experienced farmers (as many of those moving into poultry farming are), as infections that can be treated with antibiotics. Commercial breeds, such as Ross, Arbor Acres, and Hubbard, which were selectively bred for production in the milder climes of North America and Europe, often lack resilience to local conditions. Vencobb, a locally bred variation of the Cobb breed, is better able to tolerate hotter conditions, but there has been little investigation into the potential introduction of indigenous Indian breeds, such as Chittagong and Aseel, as well as those from other heat and water-stressed regions that might be more tolerant to higher temperatures, into local commercial broiler production. Climate pressures also affect how biosecurity is enacted. Most birds are raised in open sheds from which disease-carrying rodents and wild birds are hard to keep out. Temperatures in closed sheds would be uncomfortably high without environmental control,9Pawar SS Sajjanar B Lonkar VD et al.Assessing and mitigating the impact of heat stress on poultry.Adv Animal Vet Sci. 2016; 4: 332-341Crossref Google Scholar but powering such sheds is challenged by pressures on the energy system: power cuts are common and in some rural areas, electricity from the national grid is rationed for agricultural use. Self-generation of energy cannot easily fill the gap as poultry waste produces insufficient energy to power biogas digesters and energy produced by solar panels is diverted to the national grid and is subject to the same challenges. Furthermore, there is a perception that birds raised in environmentally controlled, cooler temperatures could be more susceptible to heat-related mortality during transport to, and while on sale, at live markets. If correct, this will require a concurrent shift to near-farm processing plants, chilling plants, and cold chain storage, substantially increasing the carbon footprint of the farm-to-fork food chain and the cost of meat to consumers. The Indian consumer preference for buying live birds at market would also need to change. The poultry system thus faces a number of inter-related stressors from climate change. A planetary health lens, through which the entire system is approached, could offer potential solutions. Local building materials and traditional practices that could mitigate heat stress and spread of disease risk being overlooked if poultry systems are approached only from the perspective of modernising the Indian system to Global North standards. Energy policies might need to readdress how rural areas are able to use self-generated energy. The intensive production of chickens has been identified as one of the markers of the Anthropocene.10Bennett CE Thomas R Williams M et al.The broiler chicken as a signal of a human reconfigured biosphere.R Soc Open Sci. 2018; 5180325Crossref PubMed Scopus (67) Google Scholar Chickens sit at an intersection of food systems, environmental change, global health, and biodiversity. Understanding this intersection and the pressures on the systems to which it connects could suggest potential adaptations to other stressed systems as well as helping to preserve the efficacy of antibiotics into the future. We declare no competing interests. Funding for this study has been provided under ESRC grant ES/S000186/1 and ES/S000216/1 and Indian Department of Biotechnology grant BT/IN/Indo-UK/AMR/05/NH/2018-19 Chicken or Egg: Drivers of Antimicrobial Resistance in Poultry in India (DARPI).