Should we reject animal source foods to save the planet? A review of the sustainability of global livestock production

Within the next 40 years, the global livestock industry will have to considerably increase production in order to supply the population with animal-source foods, yet the industry must concurrently improve the three metrics of sustainability – economic viability, environmental stewardship and social responsibility. Environmental stewardship is currently the area for which animal agriculture is under the most scrutiny, as many consumers perceive that animal-source foods have an unacceptable environmental cost. These concerns are intensified by activist group campaigns propounding that reducing meat consumption will have significant environmental mitigation effects. Animal-source foods have been shown to be essential dietary components for improving health of inhabitants in developing regions, for whom such foods are often economically unavailable. Moreover, reducing meat consumption in developed countries has a negligible effect upon national greenhouse gas (GHG) emissions and leads to further questions with regards to the implications for use of animal and plant by-products, and the difficulty of producing human food crops on grazed pasturelands. Improving livestock productivity has positive sustainability implications as it reduces resource use and GHG emissions whilst improving economic viability, yet it is often difficult to attain consumer acceptance of modern best practices and technologies. Productivity metrics that enhance sustainability include milk and meat yield, growth rates, feed efficiency, calving rate, parasite control and use of growth-enhancing technologies. ________________________________________________________________________________