Income Disparities and the Global Distribution of Intensively Farmed Chicken and Pigs

This has led to concerns about the impact on greenhouse gas emissions, disruptions to nitrogen and phosphorous cycles, and land use change, particularly deforestation for production of feed crops. Animal and human health are increasingly interlinked through emerging infectious diseases, zoonoses, and antimicrobial resistance. The rapidity of change has also had social impacts in many developing countries, with increased risk of marginalization of smallholder farmers. The distinction between extensive and intensive production systems is crucial in understanding the impacts and benefits of livestock farming. Extensive production systems, characterized by low input and output, are often associated with smallholder farms in low-income countries. In contrast, intensive production systems, which involve higher inputs and outputs, are prevalent in high-income countries. The proportion of animals raised in intensive production systems varies significantly between countries, depending largely on their levels of economic development. The process of intensification, by which extensive production systems are replaced by more specialized intensive farms, has been particularly rapid in much of Southeast Asia. However, the levels of intensification vary across the continent, with countries such as Bangladesh and Cambodia still relying heavily on extensive backyard systems, while countries like Thailand and Malaysia have a higher proportion of intensive production. The demand for poultry meat is forecast to increase rapidly in Asia in the coming decades, driven by demographic growth and increasing wealth. The global distribution of intensively farmed chicken and pigs is highly variable, with countries like Belgium and the Netherlands having some of the highest densities of chickens and pigs per km2 in the world. However, these animals are often hidden away in intensive production units, rather than being visible in the landscape. In contrast, low-income countries have a vast majority of chickens and pigs raised under extensive conditions by family-based smallholder farms. The transformation of market structures towards networks with fewer larger markets will likely accompany the intensification of poultry and pig production, potentially leading to significant environmental and health risks. The concentration of high numbers of animals on small areas of land creates manure management problems, leading to localized pollution of land and water resources. Additionally, animals raised in intensive production systems are particularly vulnerable to pathogens and environmental disturbances, such as temperature and air recycling. The breeds raised in these systems have been selected primarily for their production characteristics, rather than their resistance to disease.