ILRI’s Jimmy Smith on bringing science-based nuance and clarity to today’s polarized livestock debates

In the face of increasingly polarized discourse about the place of livestock in sustainable food systems, Jimmy Smith, director general of the CGIAR's International Livestock Research Institute (ILRI), delivered a keynote presentation at this year’s TropAg conference in Brisbane (31 Oct–2 Nov 2022). Smith unpacked the factors behind this dissonance, which tends to coarsen livestock debates, hamper livestock solutions from arising and further marginalize livestock-keeping communities in countries across the developing world.

‘While livestock discussions must not shy from uncomfortable truths’, Smith said, ‘they should avoid the binary worlds of absolutes.’

Smith noted that it is the sheer diversity of livestock production, processing and consumption patterns across the world—which range from dairy to beef, and poultry to pig, systems, and from industrial to medium to small family production systems—underpin many of today’s apparently conflicting views of the sector. It is this great diversity in livestock systems and their socio-economic and agro-ecological contexts, he said, that leads to the conflicting perspectives we hear about today.

Smith argued that a more nuanced and context-specific understanding of the very central and very different roles cattle, camels, llamas, water buffaloes, goats, sheep, pigs, chickens and ducks play in development around the world is essential if future food systems are to meet the immense challenges of the food, nutritional, health and livelihood needs of the world’s growing population. This nuanced understanding, he said, is especially important for addressing the livestock sectors of low- and middle-income countries, where small-scale farming and herding still dominate national economies and demand for milk, meat and eggs is rising fastest.

Smith asked his audience to consider that when it comes to the environmental footprint of livestock production and the consumption of milk, meat and eggs, ‘where one stands is a function of where one sits’.

‘Where I sit’, Smith went on, ‘is in Africa and other developing regions, which lets me perceive many common misconceptions about small-scale livestock systems.’

Smith reminded his audience that, largely due to the world’s growing populations in lower income countries, 60 per cent more food will be needed by 2050 than is produced today. Demand for beef, pork, chicken and milk, along with vegetables, is outstripping that for cereals. Most of this food is being produced on small-scale farms and on pastoral lands. But due to on-going population increases in Africa and Asia, the increasing demand for these higher-quality foods does not translate into increased consumption by most of the world’s poorer people. The average intake of these highly nourishing, and thus relatively expensive, foods in Africa and South Asia will likely stay very, very modest—just a fraction of what the average intake is in more developed regions.



‘Producing all the new food needed by the world’s rising population on a landmass that some say is already meeting its ecological limits with a farming-as-usual approach is not an option’, Smith said.

‘We are going to have to apply tremendous amounts of new science to increase our food production without using new lands or using up many more natural resources.

‘Making livestock production systems and the foods they produce—which nourish as well as feed us—more productive will be a big part of those solutions.

But first, he said, we need to get clarity on the confusions surrounding livestock and what science can do both to clear up these livestock confusions and to offer livestock-based solutions to sustainable and equitable development.



The first confusion Smith raised

was around the nutritional value

of livestock-derived foods—meat, milk and eggs.

Recent different reports have used very different metrics to determine the nutritional benefits of these foods, which has caused confusion, including for those developing nutritional guidelines for their countries and determining the roles that animal-source foods can and should play in providing healthy, balanced and nutritious diets for their citizens.

This confusion has led to a general view among some that livestock products can be harmful to nutrition. This belief has harmed the many millions of people whose nutrition and growth would benefit from greater consumption of meat, milk and eggs. Today, the preponderance of scientific evidence fully supports food-based dietary guidelines that include livestock meat, milk and eggs. Indeed, the latest reliable study estimates that more than half of the world’s regions need more—not less—animal-source foods to achieve a ‘least-cost healthy diet’.

And a very recent study highlights the significant benefits livestock-keeping provides poor rural households. Specifically, the study showed that technical solutions in the form of widespread vaccinations not only improved the health of village poultry but also significantly improved the nutrition and growth of children in the vaccinated households.

Graphic by Annabel Slater/ILRI, 2022.

The ILRI director general then went on

to the confusions around

livestock and climate change.

The first livestock-climate confusion that Smith explored was that of comparisons of ‘apples and oranges’ when applied to the world’s livestock and transport sectors. While the greenhouse gas emissions from the livestock sector are generally determined using whole life-cycle analyses—a ‘cradle-to-grave’ approach that encompasses everything involved in a production chain—only direct emissions are calculated from the transport sector (in fact, no full life cycle analysis of the transport sector has yet been reported). The fairest way of comparing emissions from the livestock and transport sectors is thus to compare the direct emissions from each, with livestock estimated to generate 5% of total emissions and transport 14%. 

Graphic by Annabel Slater/ILRI, 2022.

A second example Smith gave was the different figures generated when using Global Warming Potential 100 (GWP100) or Global Warming Potential* (GWP*) to determine methane emissions. All gases categorized as greenhouse gases have a global warming potential (GWP) value, which measures how effective each gas is at trapping heat in the Earth’s atmosphere, and thus how potent a gas is as a contributor to climate change. The most commonly used metric to quantify greenhouse gas emissions is known as GWP100. This metric converts different GHG values to their CO2 equivalents, with carbon dioxide having a half-life of 100 years. But what GWP100 did not account for was that unlike carbon dioxide, which is a long-lived gas, methane is a short-lived gas that is actively removed from the atmosphere by natural processes within about 12 years after being emitted. Thus, when methane emissions are kept constant, warming from methane stabilizes. And if we decrease methane emissions through the use of feed additives and many other solutions, a cooling effect will be induced. GWP* represents a new means of measuring global warming potential taking short-lived gas removal from the atmosphere into consideration.

As can be seen in the graph below, using GWP100 gives a high figure of 67kg of CO2 equivalent per kg of protein generated by Australian sheep meat production, but using GWP* shows a net benefit of 18.5kg of CO2 equivalent sequestration per kg of protein. Quite a difference!



Jimmy Smith further explained that what you measure can also provide very different views of the relative carbon footprints of different foods. As shown below, when measuring greenhouse gas emissions per grams of edible product for beef, rice and cauliflower, beef appears to have the highest carbon footprint. But when measuring how much greenhouse gases are emitted to produce the recommended daily allowance of essential amino acids, cauliflower and rice both have a bigger carbon footprint than beef! These are just examples of many studies making the same point for many different foods.

Other studies, Smith noted, showed that the amount of carbon safely sequestered in grazing land soils varies tremendously depending on different variables such as soil type, water and climate.

Graphic by Annabel Slater/ILRI, 2022.

Among the organizations providing reliable evidence to clear up confusions about livestock and climate change are the Global Research Alliance on Agricultural Greenhouse Gases (GRA) and FAO’s Livestock Environmental Assessment and Performance (LEAP) partnership. Among the more local initiatives is ILRI’s Mazingira Centre, which has conducted the first reliable assessments of African and Kenyan livestock-generated greenhouse gas emissions. Emission factors based on experiments conducted by Mazingira scientists are now informing the databases of the Intergovernmental Panel on Climate Change (IPCC).

The new Mazingira data showed that methane emissions from African cattle during enteric fermentation were 15% lower than previously reported, which could indicate that cattle in Africa have a lower impact on the climate than expected, and that nitrous oxide emissions from African cattle were 29% lower than prior estimates for dung deposited while grazing and similar to other estimates for urine deposited while grazing. On the other hand and partially offsetting this, sheep and goats had higher methane emissions than previously reported for Africa.

Finally in this livestock and climate section of his presentation, Smith showed how different livestock and livestock production systems have greatly different greenhouse gas compositions and intensities, which indicates that each of these livestock systems needs different solutions to become more sustainable. (These data, from Tim Robinson of FAO and Hayden Montgomery of the Global Research Alliance, are based on FAO 2013 data, updated and modified using unpublished 2015 data from GLEAM [2022]). For example, regarding optimal ways to reduce the carbon dioxide generated to produce milk, pastoral and agro-pastoral livestock systems of the Global South should focus on better animal feed, health and herd structure while the high input-high output systems typical of the Global North should focus on methane inhibitors in the animal rumen, methane biodigesters and nitrification inhibitors applied to soils.

Among the major ways for livestock systems to both mitigate and adapt to climate change are improvements in livestock production efficiencies made through better livestock health, genetics and feeds. For example, there are now genetic opportunities to breed low-methane livestock and new feeding strategies that can reduce livestock methane emissions.

In addition, genetic ways to produce heat-tolerant livestock are now being explored. Heat stress in cows matters because as it rises under climate change, milk yields decline. Recent evidence of genetic variations among bulls makes possible improved breeding programs that select ‘climate-tolerant’ animals that maintain good milk yields under heat stress while reducing their greenhouse gas intensity.

New research estimates that the world’s grasslands store approximately one-third of the global terrestrial carbon stocks and can act as an important soil carbon sink. The potential of using livestock to better manage grasslands for greater carbon storage is quite large, with some opportunities for grassland carbon sequestration being close to that for forests. Recent studies show that improved grazing management and biodiversity restoration can provide low-cost and/or high-carbon-gain options for natural climate solutions in global grasslands.

For his third topic,

Smith discussed a few confusions

muddling livestock-environment issues.

First, Smith asked his audience to consider the commonly reported figure of 15,000 litres of water needed to produce 1 kg of beef. That, Smith said, is a global figure that includes, for example, the large amounts of water required to feed cattle kept in the feedlots of rich countries. But most livestock in developing countries (as well as Australia) are raised on rangelands, where virtually all the water used by livestock comes in the form of rainfall or stream run-offs rather than freshwater. Most of the water is not ‘consumed’ as such.

Graphic by Annabel Slater/ILRI, 2022.

Graphic by Annabel Slater/ILRI, 2022.

Contrasting measures used to determine how much land livestock use also cause confusion. While livestock use over half of the world’s land surface, 21% of that land can only support livestock—that is, the land is too dry or mountainous for crops. And a further 24% of the world’s land surface supports livestock raising along with crop production—and these are the ‘mixed farms’ that feed most of the world!

Graphic by Annabel Slater/ILRI, 2022.

In addition to this, the amount of feed resources required by livestock is often overstated. Research shows that 86% of the global livestock feed intake in dry matter consists of feed materials that are inedible by humans.

Graphic by Annabel Slater/ILRI, 2022.

Among the ways forward for sustainable rangeland development are managing these ecosystems and planning grazing with local communities. Such participatory methods are today helping pastoral communities to rehabilitate their rangeland ecosystems, to secure land tenure and to increase their resilience to climate and other shocks.

Among the biggest opportunities to provide more, and more nourishing, feed for ruminant animals is making better use of the straw and stover by-products of crop production, which, in lower income countries, make up more than half the feed of ruminants. Research on cereal, legume and tuber crops shows that genetic variation in their livestock feed traits can be exploited to increase livestock productivity by 15–25% with little to no trade-offs in grain yields. Superior ‘dual-purpose’ (feed as well as food) crops are now being bred to make their residues more nourishing for cattle, buffaloes, sheep, goats and camels.

Smith concluded his presentation by reiterating that the multiple and contrasting metrics being used to assess livestock issues in human nutrition, climate change and environmental health are causing confusion.

The need to meet the growing demand for food, especially livestock-derived foods in the developing world, on today’s resource base is a tall order, he said, 'but it’s one that can be achieved with the help of science. But we will achieve it only if we do not allow our different perspectives to detract from the immense task at hand—that of ensuring sustainable healthy diets for everyone.’

Watch or download Jimmy Smith's keynote slide presentation at TropAg 2022, Brisbane, 2 Nov 2022:

Science-fiction or science-fact? Research for sustainable livestock agri-food systems


About livestock research for development

The International Livestock Research Institute (ILRI) works for better lives through livestock. It conducts science to improve food and nutritional security and to reduce poverty and environmental degradation in developing countries through research for efficient, safe and sustainable use of livestock. With some 700 staff and an annual operating budget of about USD80 million, ILRI has two principal campuses, located in Kenya and Ethiopia, and another 14 regional and country offices and projects across Asia (East, South and Southeast) and Africa (Central, East, Southern and West). ILRI is part of CGIAR—the world’s largest agricultural research partnership working for a food-secure future—and is the only CGIAR research centre with a mission to develop sustainable animal agriculture in low- and middle-income countries. 

As they have since the dawn of agriculture, livestock continue to benefit the world in many, big and critically important ways. Livestock continue to be kept by more than one billion poor people today. Livestock-based livelihoods are a proven pathway out of poverty and are uniquely important to women and youth. Livestock foods make up the highest-value agricultural commodities worldwide and are in rapidly growing demand across lower income countries, where this highly dynamic sector is providing huge new development opportunities in such critical areas as jobs and income and food and nutritional security.

At the same time, livestock can also be a potent source of problems, including the significant levels of greenhouse gases they emit, the emerging infectious diseases they can transmit to people, the rising incidences of antimicrobial resistance in drugs used to treat common infections in both people and animals, and ill health resulting from consuming contaminated milk, meat and eggs.

Enhancing the ‘goods’ of livestock while mitigating the ‘bads’ requires significant increases in research and development investments and partnerships. With the diverse and fast-growing livestock sectors of developing countries undergoing unprecedented transformations today, whether we choose to invest or not invest in the ubiquitous small-scale livestock systems of poor countries will have big impacts globally.