Director of Teagasc Professor Frank O’Mara gave the keynote address at the recent British Society of Animal Science conference, which took place in Belfast on Tuesday 9 April. The conference, which was attended by animal scientists from all around the world heard, about the role and importance of the livestock sector, the evolution and legitimacy of livestock production and the three big environmental pressures – climate, biodiversity and water. They also heard what components can help to improve sustainability, along with how research and innovation can help.

–Adam Woods

The main output of livestock in agriculture is animal-sourced food. This makes a big contribution to global food and nutrition supply, particularly protein.

Animal-sourced foods are sources of high-quality protein, and are also excellent sources of highly available minerals and vitamins and various bioactive components (taurine, creatine, camosine, conjugated linoleic acids).

It’s important to remember that global food consumption is expected to increase by 1.3% per annum over the next decade, and that meat and milk consumption are also projected to rise according to the Organisation for Economic Co-Operation and Development (OECD).


Livestock are also an important part of the agriculture sector, representing 44% of the total EU agricultural output in 2023.

Ireland has the highest animal output as a share of total agricultural goods output, which stood at almost 80% in 2023.

The value of livestock production in Europe (EU-28) in 2017 was estimated at €170bn, and it employs approximately four million people.

The wide distribution of livestock in rural areas makes it an important contributor to the economy and vitality of rural communities.

The output of animal-sourced foods makes livestock an essential part of the global food system. Over the years, higher yields and greater production have enabled food suppy to keep pace with a rapidly growing world population.

Together with crops grown for food and feed production, they give circularity to our food system, which is essential for soil health, and is helpful to optimise the use of available resources.

Where this circularity is challenged or absent due to an excess of crops or animals in a region, the system can come under pressure, with impacts on water quality, biodiversity or soil health.

A diversity of livestock systems is important for resilience of the livestock industries, the food they supply and the overall food system.

A diversity of livestock systems allows production to be optimised to local conditions, and provides a range of animal sourced foods, which are diverse in aspects such as cost to consumers, taste, nutritional value and versatility for meal preparation.

Sustainability (economic, environmental and social) is a key consideration in today’s food systems. The contribution of livestock production to climate change receives much attention.

Other considerations

Still, environmental sustainability has many other considerations: water quality, biodiversity, circularity (e.g. the return of animal manures to the areas where their feed is produced), soil health, the ratio of human edible food: human non-edible feed in the diet of livestock, antibiotic and pesticide usage, animal welfare.

This results in a complex landscape with several interconnections, benefits and trade-offs, and livestock’s contribution to environmental sustainability cannot be easily assessed using a single-dimension analysis such as a life cycle assessment of its carbon footprint.

Without livestock there is no way of bringing most of the world’s dry matter production into the human food supply chain. A multi-dimensional assessment is needed, and livestock can contribute positively to most of the dimensions outlined above, but the contribution can also be negative in the wrong circumstances (e.g. a manure surplus due to overstocking, causing water pollution).

Crop rotation and diversification of land use result in a higher diversity of species and allow a reduction of pesticides. Half of bird species depend on grassland habitats for food and reproduction.

Soil under permanent grassland has a high level of carbon and biodiversity of invertebrates.

Methane, a greenhouse gas, is the second largest contributor to global warming after CO2. In an EU context, agriculture is the largest source of methane emissions, followed by waste at 26% and energy at 19%.

Methane from energy should be tackled first, as it can be cut quickest and at the least cost. Minimising biodegradable waste from going into landfill should also be a priority.

Agricultural emissions should be reduced as much as possible, but some methane emissions from livestock is unavoidable (unique ability to convert fibre to food).

Breeding, lifetime efficiency, diet, additives, manure management and animal health all have an impact on methane emissions at farm level.

More than food

While food is the main output of livestock production, livestock are much more than food.

Other products from livestock production include hides, wool and hair, offal and other by-products like collagen and gelatin, foods with enhanced nutritional effects, compounds used in medicine such as insulin, heparin and hyaluronic acid, manures for fertiliser and fuel (e.g. biogas), biodiversity and landscape and fire management, contributions to culture and wellness, as well as being an integral part of vibrant rural communities in many regions.

These products, together with food, illustrate that livestock plays a very important role in our economy and our ecosystem.

We can’t have a sustainable circular food system without livestock. Livestock facilitate crop diversification. They are recyclers by nature and they convert biomass to food, and they provide organic fertilisers which contribute to soil health.

A diverse set of livestock systems are needed because of varying agro-climatic conditions – it’s not a one size fits all situation.

A diversity of systems also gives more resilience to the overall system from shocks such as climate/weather, input prices, availability and disease.

In Short

  • Global food consumption is expected to grow by 1.3% per annum over the next decade.
  • 58% of EU farms hold animals.
  • Value of livestock production in EU is estimated at €170bn.
  • Livestock production employs four million people across EU.
  • 50% of bird species depend on grassland habitats for food and reproduction.
  • Crop rotation and diversification of land use result in a higher diversity of species and allow a reduction of pesticides.
  • Livestock’s legitimacy is often questioned, but their role in our food system make them too valuable to dispense with.