Skip to 0 minutes and 11 secondsHello, my name is Mark van der Giezen. I'm an associate professor of evolutionary biochemistry. Humans have supplemented their diets with animal protein for a very long time. Well before the emergence of homo sapiens, primitive men were scavenging and hunting animals. Farming of animals developed around 10,000 years ago and the domestication of livestock probably predates domestication of plants. Meat is rich in protein, amino acids and several essential micronutrients, and is a valuable addition to a plant based diet. Even the recent review by the EAT-Lancet Commission, which is rather critical about livestock farming, recommends including meat in a healthy diet. The main problem, as with many issues, is overconsumption.

Skip to 0 minutes and 52 secondsThe overconsumption of poor quality processed meats lead to unsustainable practices as farmers need to produce this meat using very small profit margins. This unfortunately leads to animal welfare issues and serious pressures on the environment. So far the unfortunate trend has been that, as countries get wealthier, inhabitants demand Western diets rich in processed food and animal protein with all the associated health risks. So, we need to get away from poor Western diets that include processed food. However, totally banning livestock is probably not the answer to the problem.

Skip to 1 minute and 25 secondsIt might seem a simple solution for reducing greenhouse gas emissions and producing healthier food, especially as ruminants, grazing animals like sheep and cows, have a bad name when it comes to greenhouse gas emissions and efficient food production. Other animals, for example pigs and poultry, are suggested to be much better sources of protein. This is because ruminants appear to be inefficient at converting the plants they eat into human food. However, ruminants have evolved to live on marginal lands which are otherwise useless for agriculture. And of course, they largely consume a plant that cannot be eaten by humans-- grass.

Skip to 1 minute and 58 secondsIf food conversion ratios, which measure the efficiency with which livestock convert animal feed into human food, take this into consideration, then ruminants are not as bad as generally thought. It would be much better to reduce intensive livestock farming, but to let the ruminants graze extensively on marginal lands where they can produce high quality meat full of essential micronutrients. Another often forgotten aspect of livestock is the important cultural and societal roles they play in developing nations. People in highly developed societies forget that not everyone in the world has a bank account or access to a cash machine. Animals are often used as crucial assets and investments in lieu of bank and savings accounts.

Skip to 2 minutes and 37 secondsThere can be a vital part of the economy, particularly in highly rural societies. The consequences of removing livestock from such settings should not be underestimated. The main challenge is how to reduce the environmental impact of livestock farming, but to retain high quality protein they can provide to support human health. This will mean a drastic reduction in the amount of meat we consume, while retaining the additional roles livestock play in various human societies on our planet.

Livestock farming and the environment

In this video, Dr Mark van der Giezen discusses global meat consumption and highlights the differences between livestock production systems in terms of greenhouse emissions.

The next step is a useful article which explores whether eating meat can ever be sustainable.

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Future Food: Sustainable Food Systems for the 21st Century

University of Exeter

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