Animal agriculture is being challenged from many entities for its production model, animal care, management practices, disease prevention and environmental management.

This criticism is coming from both within the animal agricultural fields of research, consumers, government regulatory agencies, as well as external forces led by various animal rights groups, environmentalists, and activist vegetarians (Anderson, 2012). To objectively address some of these challenges policy makers are encouraged to utilise scientific findings related to the carbon footprint of the poultry industry.

It is essential that science-based evidence is considered when developing policy associated with production agriculture and the realities of food production needs to meet the demand to provide food to a growing population (Anderson, 2013). Dewey (1938) indicated that much of the commentary associated with these issues uses wording that is couched negatively even though the truth is positive.

The reality is that the productivity and health of the livestock grown for food has never been better. Research in both the US and EEC since 2006 has shown that in the animal production sectors, poultry meat and egg production appears to be the most environmentally efficient, followed by pig meat and sheep meat (primarily lamb) with beef the least efficient (Williams et al., 2006). However, Dr Williams stressed that Global Warming Potential (GWP) varied depending on the different types of poultry farming methods.

Using the egg layer industry as an example, Anderson et al. (2013) indicated that today's laying hens are in general smaller, have less mortality, have higher and more persistent levels of production, produce larger eggs with better shell quality, and are more efficient commercial layers in the middle of the 20th century. Pelletier et al. (2014) reported that on a per-kilogram of eggs produced basis, the environmental footprint of the US egg industry in 2010, versus 1960, was: 71 per cent lower in greenhouse gas (GHG) emissions; 71 per cent lower in eutrophying emissions; 65 per cent lower in acidifying emissions. These research groups found that feed efficiency, feed composition and environmental management were key components in minimisation of the carbon footprint and subsequent emissions.

Much debate has focused on egg production systems and environmental impacts. Williams et al. (2006) indicated that if the egg industry moved towards all cage production, GWP would fall by 10 per cent as compared to going all free range would increase GWP by 10 per cent. They also showed that organic egg production requires 14 per cent more energy than non-organic and increases most environmental burdens by 10 per cent to 33 per cent (except pesticides) but the land area needed more than doubles. Comparing non-organic systems, keeping 100 per cent hens caged incurs 15 per cent less energy than 100 per cent free range, with similar differences for most other environmental burdens, although the housing resource is 10 per cent higher for caged birds and land use 25 per cent less.

The overall impact for converting to all-organic production systems would result in a 40 per cent increase in GWP. The primary reasons were organic systems for egg production require more energy, and the birds have a lower feed conversion (eat more feed). Feed accounts for most of the energy required in poultry production agriculture and is a key driving factor for GWP.

If our objective is to provide a growing global need for affordable high quality animal protein products (such as eggs) with minimal environmental impacts to society, it is essential that all scientific evidence is considered in an objective forum by all impacted stakeholders.

References

Anderson, K.E. 2012. The ever changing landscape of animal production practices. National Extension Workshop: “Change & Challenge: What Lies Ahead for the Poultry Industry?” July 9, 2012. Poultry Sci. Suppl. 91:4.

Anderson, K.E., G. B. Havenstein, P. K. Jenkins and J. Osborne. 2013. Changes in commercial laying stock performance, 1958- 2011: thirty-seven flocks of the North Carolina random sample and subsequent layer performance and management tests. World’s Poultry Sci. J. 69:489-513.

Dewey, J. 1938. The ethics of animal experimentation. American Medical Association, Bureau of Health and Public Instruction, Chicago, IL.

Pelletier, N., M. Ibarburu and H. Xin. 2014. Comparison of the environmental footprint of the egg industry in the United States in 1960 and 2010. Poultry Science. 93:241–255 http://dx.doi.org/ 10.3382/ps.2013-03390

Anon. 2014. Comprehensive study finds that the environmental footprint of the US egg industry Has fallen sharply over the last 50 years due to improved production techniques, Champaign, IL– According to the results of a new study published in Poultry Science.

Williams, A.G., Audsley, E. and Sandars, D.L. 2006. Determining the environmental burdens and resource use in the production of agricultural and horticultural commodities. Main Report. Defra Research Project IS0205.

Anderson K.E. 2013. Animal welfare regulations and food production. In 'Guide to US Food Laws and Regulations', Second Edition. Edited by Patricia Curtis. John Wiley & Sons, Ltd. p227-238.

November 2014