How sustainable is sustainability?

Sustainability in agriculture is a topic of much discussion, particularly as it relates to raising specific livestock such as pigs. But what IS sustainability in agriculture? The United States (US Code Title 7, Section 3103) defines sustainable agriculture as:

an integrated system of plant and animal production practices having a site-specific application that will over the long-term: Satisfy human food and fiber needs; enhance environmental quality and the natural resource base upon which the agriculture economy depends; make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls; sustain the economic viability of farm operations; and enhance the quality of life for farmers and society as a whole.

Simplified, sustainability can fit into four areas—environmental, economic, societal, and health/wellbeing. 

As described in Vanderohe et al, to reduce environmental impact, the swine industry has used genetic selection (in other words, breeding decisions), enhanced and/or precision nutrition, altered management, and building/mechanical advancements. Breeding for increased feed efficiency and improved maternal behaviors and reproductive traits can increase the amount of product produced with similar or reduced resources. 

The environmental impact of swine production has been reduced through precision feeding and dietary strategies to increase feed use and decrease nutrient excretion. Capturing excreted nutrients for further use as fertilizer is an important management strategy, but this requires proper handling and use to prevent unintentional negative environmental impacts. Further, dietary additions such as phytase can result in a more optimal nitrogen to phosphorous ratio in the animal waste, therefore allowing more nutrients to remain in the soil once applied. However, reducing greenhouse gas emissions will require additional changes to manure processing. 

Increasing animal growth rates, number of animals, and concentration of swine production can create health challenges. Several viral pathogens pose critical risks to swine production (African swine fever, porcine reproductive and respiratory virus, etc.) due to their devastating consequences to the animal/herd, lack of vaccination and treatment options, and fast transmission between animals. Bacterial pathogens pose different challenges; as we face limited diagnostic tools, rapid pathogenesis of many organisms, increased antibiotic resistance, and decreased public acceptance of antibiotic use. There is a need to focus on controlling stressors to minimize immunosuppression and maximize ability of the animals to resist infection, all while improving biosecurity measures that will continue to protect the animals and workers themselves. 

The public has added animal welfare to many definitions of sustainability, with three major concerns: physical functioning (animal should be able to function/thrive and not be pushed to mental or physical failure), naturalness (expression of natural behavior of the species), and subjective interactions (the animal can experience positive states, with reduced negative states within its environment). For example, increased public attention in these areas has led to increased pen sizes for various species and contention over the use of farrowing crates for sows. However, there’s a need to balance improvements in efficiency and sustainability with societal acceptance. If an improvement isn’t accepted by consumers, it will not be profitable. For example, the Enviropig, a genetically altered pig which drastically reduced phosphorus excretion (thus lessening the environmental impact) was not ever approved for consumption and received much criticism from the public despite its potential positive impact on nutrient balance. 

Changes to management such as larger pen sizes can increase the cost of production while simultaneously reducing the number of animals that can be housed. In general, there are increased costs to the producer to support sustainability. These increased costs require the producer to increase yield or increase product price to remain economically sustainable. However, overall consumer opinions on sustainability and animal welfare are not widely reflected in their consumer behaviors and purchasing decisions. 

As we move forward into increasing sustainability in agriculture, it’s important to remember that sustainability in the swine industry is but a piece of a larger puzzle of animal agriculture, which itself is a piece of the large puzzle of global sustainability.