Environmental sustainability of livestock production

Authors: Rotz, Clarence - Al

Submitted to: Meat and Muscle Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2020
Publication Date: 5/26/2020
Citation: Rotz, C.A. 2020. Environmental sustainability of livestock production. Meat and Muscle Biology. 4(2):1-18. https://doi.org/10.22175/mmb.11103.
DOI: https://doi.org/10.22175/mmb.11103

Interpretive Summary: Global demand for livestock products is increasing, but there is also increasing concern for the effects of livestock production on our environment. Although much attention is given to livestock’s effect on global warming, this may not be the greatest concern. Livestock manure is the major source of ammonia emission to the atmosphere, and a contributor to other reactive nitrogen losses. These emissions have a number of adverse effects on air and water quality with effects on human health and the biodiversity and stability of sensitive ecosystems. Livestock production also requires large amounts of freshwater and diminishing supplies and increasing demands may constrain production in some regions of the world. The greatest threat to the sustainability of livestock products though, is food loss and waste. As we look to feed an increasing global population, focus must be given to better utilize the food produced to make best use of available resources and reduce emissions to the environment.

Technical Abstract: The environmental impact of livestock production has become an important and controversial global issue, primarily due to reported impacts on global warming. This issue applies to all of the major meat animals, but especially those of beef cattle due to their emission of enteric methane. Livestock production has a role in global warming, but the importance of their contribution may be overstated. Their impact is primarily through methane production, which does not have a long-term effect in the atmosphere. Methane is a potent greenhouse gas, but it oxidizes in the atmosphere recycling carbon back to the form of carbon dioxide. Therefore, livestock production only affects global warming through increased animal numbers or other increases in greenhouse gas emissions. Animal numbers are increasing globally so their impact cannot be ignored. A more important environmental consideration is that of reactive nitrogen emissions where ammonia from manure is the form of most concern. Global estimates suggest that 63% of ammonia emissions come from agriculture with 44% from livestock manure. Ammonia emissions have important impacts related to acidification of ecosystems, eutrophication of surface waters and human toxicity through the formation of small particulate matter. Water consumption is another important concern. Global estimates suggest that agriculture uses about 70% of freshwater withdrawals with about 20% used for livestock feed production. Although livestock production is not a large energy consumer, fossil fuels are a limited resource that always must be considered. Many technologies and strategies exist for mitigating the environmental impacts of livestock production, but finding economical solutions is challenging. Mitigation must start with the reduction of food waste. Livestock impacts are best-reduced using intensive practices to produce animals in less time and with fewer resources. Intensive production using diets that accurately meet animal nutrient needs is an important mitigation option to reduce animal numbers and their associated emissions and resource use.