Research reveals the environmental footprint of the egg industry

NO YOLK: 68 million tonnes of eggs are produced worldwide

To determine the environmental implications of egg production in Europe, a team of Spanish researchers has taken as its model an intensive poultry farm located in Asturias, with 55,000 laying hens and an annual production of more than 13 million eggs. The results were published in the Journal of Cleaner Production.

The scientists from the University of Oviedo analysed the effect of intensive egg production on 18 environmental categories, among which are ozone depletion, climate change, terrestrial acidification, human toxicity and land occupation.

“The most affected have been the transformation of the natural earth and the water and land toxicity,” said Amanda Laca, a researcher at the Department of Chemical Engineering and Environmental Technology at the University of Oviedo to Sinc.

The analysis shows that the greatest impacts in 16 of the categories are derived from the production of the feed supplied to the laying hens.

“The choice of the ingredients that constitute the feed is a key factor,” stressed the researcher. She added that it was important to use feed cultivated in an environmentally-friendly manner.

Another factor that generates important harmful effects is the replacement of the elder hens by new layers.

“An increase in the useful life of the layers would contribute to reduce the derived impacts, although this factor must be treated together with economic and productive aspects”, said Adriana Laca, Professor at the University of Oviedo. The effects associated with the manufacture of materials used in the packaging of eggs also harm the environment.

However, transport only represents a remarkable effect on the category of ozone depletion. In addition, emissions of methane, ammonia and nitrous oxide, and electricity, water and cleaning products barely contribute to the total of impacts generated.

The scientists obtained a carbon footprint per dozen eggs of 2.7 kg of CO₂ equivalent, “a value similar to other basic foods of animal origin such as milk and much lower than that of veal, pork or lamb,” Laca added.

“It is important to highlight the beneficial effect that the recycling of waste has on the environment, as well as the use of elder chickens as poultry meat for human consumption.”

In recent years, egg production has been in the spotlight for animal welfare issues. While in most European countries the number of farms with free-range hens has increased, in Spain 93 per cent of laying hens are still caged.  In the rest of the EU, the figure is much lower (40 per cent) due to a growing concern for animal welfare.

Egg production has increased in recent decades and has reached a volume of 68 million tons worldwide. The main reason is that chicken eggs are not only a valuable source of protein, but also an affordable resource for any pocket.

Currently, about 7 million tons of eggs are produced each year in the European Union. Spain is one of the largest producers with 1,260 farms and an average of 67,700 chickens each. Together with France, it represents about 25 per cent of European production, according to the Ministry of Agriculture, Fisheries, Food and Environment.

In addition, the production of eggs, like other intensive farms, generates negative effects in nature, such as the emission of greenhouse gases or the contamination of soil and water.

But it was not until the 1980s that intensive livestock farming began to be considered an environmental problem.