The following technical article is related to the event:
Animal Nutrition Conference of Canada 2021

The role of livestock in sustainable food production systems in Canada

Published on: 9/13/2021
Author/s : Kim Ominski 1, Tim McAllister 2, Karin Wittenberg 1, Getahun Legesse 1 and Kebebe Gunte 1 / 1 Department of Animal Science, University of Manitoba, Winnipeg, MB; 2 Agriculture and Agri-Food Canada, Lethbridge, AB.

Global drivers such as the growing human population, continuously evolving consumer preferences, globalization, and climate change have put pressure on the agri-food sector to produce more livestock products with less land, less feed and less water. Taste, nutritional value, cost, source and environmental sustainability of food has become an essential element of purchasing decisions for many consumers. Indeed, an environmental footprint composed of greenhouse gas emissions, nutrient and water use efficiency, water quality, carbon storage and biodiversity has been completed for many commodities. However, as livestock production systems are complex agro-ecosystems that typically include each of these parameters, it is extremely challenging to establish a single value to assess overall sustainability. This complexity presents a grand challenge to all stakeholders in the livestock value chain – producers, processors, retailers, nutritionists and researchers - to improve the sustainability of our agro-ecosystems, as well as to share this information with the consumer. There is no silver bullet to solve the environmental concerns of all livestock production systems as they operate under different constraints on different landscapes, with different water and nutrient cycles, plant and soil types and a myriad of other factors. Further, the lack of scientific evidence regarding the interactions between livestock production, human nutritional adequacy, and the health of our environment makes it difficult for consumers to interpret this information and make informed food choices. This presentation will examine these complex interactions and trade offs, as well as the potential impacts of changes in consumer dietary choice on environmental sustainability, nutritional adequacy and land use. It will also challenge the agricultural sector to consider strategies by which we can engage with consumers in more fulsome conversations regarding the sustainability of livestock production systems.

Global drivers impacting food production and consumption

The agricultural sector is faced with the daunting challenge of producing food for a growing global population, which is expected to reach 8.5 billion by 2030, 9.7 billion by 2050 and 11.2 billion by 2100 (UN WPP 2019), with sub-Saharan African countries accounting for more than half of the growth of the world’s population between 2019 and 2050 (Figure 1; UN WPP 2019).

Figure 1: World population by region projected to 2100, based on the United Nation’s medium population scenario (UN WPP 2019).

World population by region projected to 2100, based on the United Nation’s medium population scenario (UN WPP 2019). 

Population growth, along with increased socio-economic status and urbanization (Motett et al., 2017) are expected to increase global demand for meat and milk by 57% and 47%, respectively (Alexandratos and Bruinsma, 2012). The majority of growth is expected to occur in developing countries (Motett et al., 2017). The East and Southeast Asian region is expected to realize income grow of 60-100% /capita by 2028, resulting in a greater demand for meat, leading to a 5 kg/capita increase in China and 4 kg/capita increase in Southeast Asia, largely due to greater poultry and pork consumption, the two meats most widely consumed in those regions. Beef consumption in China is also expected to rise by 0.5 kg/capita over the next decade, bringing average consumption to 4 kg/capita. In South Asia, income growth is projected to be associated with greater consumption of dairy products, sugar and vegetable oil. Dairy products and pulses will remain critical sources of protein within this region. Pakistan is expected to lead global dairy consumption growth, with annual consumption of 274 kg/capita, nearly 30% of total daily per capita protein availability. Dairy consumption is projected to grow in India as well, and will account for 15% of total per capita protein intake by 2028 (OECD-FAO, 2019). This growth in the global demand for animal-based protein could present opportunities for growth in Canadian export markets. 

Over the last decade, consumption of chicken has increased, while consumption of beef, pork and fluid milk has decreased in Canada. However, a recent Canadian survey (n=1029) revealed that more than 48% of respondents stated that they consume meat daily while 40% consume meat once or twice per week (Charlebois et al., 2020). Further, 82% stated that they do not have dietary restrictions, 10% considered themselves flexitarians, 1.2% were pescetarian, 1.1% were vegan, 1.2% were lacto-ovo vegetarian and 2.1% were vegetarian (Charlebois et al., 2020). 


Consumer preferences and consumption of animal-based foodstuffs

Cultural appropriateness, taste, nutritional value, cost, source, availability, ethical considerations and environmental sustainability of food products influence the purchasing decisions and consumption patterns for many consumers. The nutritional attributes of livestock commodities are well documented. Red meat is a source of several essential trace elements, often present in a highly-absorbable form (Rooke et al., 2010; Williamson et al., 2005). Animal-based food products provide a significant portion of the essential fatty acids (23-100%) and amino acids (34-67%) available for human consumption in the U.S. (White and Hall, 2017).

In the last decade, links between diet, nutrition and environmental sustainability have increased the complexity of diet selection for consumers as they search for a sustainable diet. The FAO defines sustainable diets as those with low environmental impacts which contribute to food and nutritional security and to a healthy life for present and future generations. Sustainable diets are protective and respectful of diversity and ecosystems, cultural preferences, accessible, economically affordable, nutritionally adequate, safe and healthy, while optimizing natural and human resources (FAO, 2010). The sustainability of animal-based diets has been widely criticized, with an emphasis on the adoption of plant-based diets to reduce global agricultural greenhouse gas emissions, reduce land clearing and improve human health outcomes (Tilman and Clarke, 2014; Willett et al., 2019). A simulation study examining the GHG impacts of removing animals from the US agricultural production system projected a meniscal overall reduction in GHG emissions of 2.6% (White and Hall, 2017). 

Consumer preferences regarding best practices associated with animal-based products can also impact environmental sustainability. Studies in the US (Capper and Hayes, 2012) and Canada (Basarab et al., 2012) have shown that use of productivity enhancing technologies such as implants, ionophores and beta agonists led to a 5 to 10% reduction in GHG and ammonia emissions, as well as a 10% reduction in land use required to produce the same quantity of beef. 


Environmental footprint of animal-based products in Canada

Consumer interest in environmental sustainability has led to an examination of the carbon footprint of both animal- and plant-based agricultural commodities. An environmental footprint of a product is a valuation of sustainability indicators including GHG’s, nutrient, land and water use efficiency, water quality, carbon storage and biodiversity throughout the supply chain. The choice of the functional unit, which for GHG’s can be expressed as net emissions, emissions per unit of commodity expressed on a weight basis, or emissions per kg of nutrient can significantly influence study outcomes. For example, GHG emissions of processed fruits and vegetables expressed on a weight basis were lower than meat and meat products, milk and dairy products, grain and other foods, as well as sweets (Drewnowski et al., 2015). However, when expressed per 100 kcal of energy, vegetables had the highest emissions relative to all other categories. Several studies have also examined the relationship between the nutrient density of foods and GHG emissions, demonstrating that animal-based commodities have consistently lower emissions when adjusted for energy (Vieux et al., 2013), protein (Veeramani et al., 2017) or overall nutrient density (Brunn Werner et al., 2014) compared to if the emissions for that commodity were expressed on a weight basis.

A novel approach to assess the sustainability of livestock production systems is a comparison of global feed conversion ratios (protein MT/year, kg dm/kg protein, kg edible dm/kg protein, kg edible dm/kg meat, kg complete dm/kg protein, kg edible protein/kg protein) as described by Mottet et al., (2017). These researchers report that of the 6 billion tonnes of feed consumed annually (including 1/3 of annual global cereal production), 86% of which is considered unsuitable for consumption by humans. Furthermore, Mottet et al. (2017) estimated that on a global basis, an average of 2.8 and 3.2 kg of potentially human-edible feed are required to produce 1 kg of boneless meat in ruminant and non-ruminant production systems, respectively; values well below that which are often cited in the literature. 

In Canada, agriculture accounts for 8.1% of total greenhouse gas emissions (Figure 2, Environment Canada 2019) and although this is a small contribution compared to other sectors, environmental footprints have been established for several commodities including beef, dairy and eggs. 

Figure 2. Breakdown of Canada’s greenhouse gas emissions by sector in 2018.

Breakdown of Canada’s greenhouse gas emissions by sector in 2018.

Over a 30-year time period (1981-2011), Canadian beef producers have reduced GHG emission intensity by 15% (Legesse et al., 2016) with 24% less land, ammonia emission intensity by 17% (Legesse et al., 2018) and water use intensity by 20% (Legesse et al., 2018). Similarly, in another study conducted in the US, the nation’s beef industry in 2007 required 70% of the beef cattle, 88% of the water, and 67% of the land required in 1977, to produce the same amount of beef while the carbon footprint per unit of beef declined by 16% (Capper, 2011). An environmental footprint has also been conducted for milk in Canada. Over a 20-year period from 1991 to 2011, fat and protein corrected milk (FPCM; kg/cow/year) increased by 43%, while enteric methane (kg CO2/kg FPCM) and total emission intensity (kg CO2/kg FPCM) were decreased by 22% (Jayasundara and Wagner-Riddle, 2014). Similarly, Pelletier et al. (2017) examined the environmental footprint of the egg industry from 1962 – 2012 and reported a decrease in industry total GHG emissions were 57% lower while energy, land and water use decreased by 10%, 71% and 53% lower, respectively.

Improvements in emission intensities in all livestock sectors has occurred as a result of improvements both in animal productivity (reproductive efficiency, weaning weight, carcass weight) and crop yields (barley grain, barley silage, corn grain, and corn silage) as well as irrigation efficiency (Legesse et al., 2016). Production intensity and emission intensity are inversely related, therefore use of precision technologies in livestock production systems can improve sustainability. 

An additional outcome of these studies is an examination of the use of human-edible vs non-edible ingredients in livestock diets. Legesse et al. (2016) estimated that approximately 80% of the feedstuffs that cattle in Canada consume in their lifetime are forage-based. Much of this forage is produced on pasture which comprises nearly one-third of all the agricultural land in Canada and is often not suitable for crop production. These values are consistent with those reported on a global basis where approximately 86% of global livestock feed dry matter intake consists of feed materials that are not suitable for human consumption and 57% of land used for feed production is not suitable for food production (Mottet et al., 2018). 

Region of production can also yield significant differences in emissions per unit of output as there is significant global variation between developing and developed regions in net emissions and in emissions for specific commodities including milk (Gerber et al., 2011). Milk produced in Canada has a footprint of 0.92 kg CO2e/kg milk while the global average is 2.5 kg CO2e/kg milk.

Figure 3: Average greenhouse gas emissions associated with milk production globally and in Canada

Average greenhouse gas emissions associated with milk production globally and in Canada


Complexity of agroecosystems

Most often, environmental footprints examine only one or two sustainability indices associated with these complex agro-ecosystems as it is extremely challenging to establish a single value to assess overall sustainability. Elements of livestock production systems including carbon sequestration, biodiversity and other ecosystem services, are metrics that are often overlooked in life cycle analysis and footprinting. Indeed, the sustainability of these diverse and multi-functional systems and their role in a circular bio-economy (Figure 4) are difficult to measure and to communicate to the general public. 

Figure 4. Livestock and sustainable agriculture: the circular economy

Livestock and sustainable agriculture: the circular economy

As a result of the inherent complexity of livestock production systems, the implications of removal of livestock from the landscape are not readily apparent. Animal-based food products contribute 18% of global calories and account for 25% of protein consumption by humans (FAO STAT, 2016), in addition to providing a variety of micro-nutrients. The FAO has identified an inverse relationship between consumption of animal-sourced foods (g/day) and human nutrition expressed as the global hunger index (FAO, 2018). A small decrease in emissions associated with the simulated removal of livestock from the landscape in the US (White and Hall, 2017) led to a greater excess of dietary energy and increased dietary deficiencies. Similarly, respondents who reported less meat and dairy or no meat and dairy in a 24-hr recall study in France, consumed less protein and several micronutrients, possible increasing the risk of deficiencies (Seves et al., 2017). 

From a global perspective, the role of livestock extends beyond nutrition, having social, economic, cultural and political implications in developing countries (Riethmuller, 2003). Not only do they provide essential nutrients for early childhood cognitive development, livestock have the potential to be “transformative” providing cash necessary for food staples, farm inputs, and education, as well as draft power and manure as a fertilizer (Smith et al, 2013). 

In addition to diet selection, as consumers, we all have a role to play regarding the environmental impact associated with food waste. Globally, food waste and loss is staggering – with losses of 30% for cereal foods, 45% for fruits and vegetables, 20% for oilseeds and pulses, 45% for roots and tubers, 20% for dairy, 30% for fish and seafood, and 20% for meat (Mottet, 2019). In Canada, total avoidable and unavoidable annual waste along the food value chain is approximately 35.5 million metric tonnes, 32% of which is avoidable and valued at $49.5 billion. This represented 51.8% of the money Canadians spend on food, 3% of Canada’s 2016 GDP and enough food to sustain every person in Canada for almost 5 months (Gooch et al., 2019). 


Strategies for engagement with consumers

As stakeholders in the livestock sector, we are eager to share our knowledge with consumers. How we capture their attention is an ever-allusive challenge. Engagement between industry stakeholders and consumers in Canada has been facilitated through provincial programs including Agriculture in the Classroom, Open Farm Day, as well as national initiatives including the Canadian Centre for Food Integrity whose mandate is to coordinate research, dialogue, resources and training in Canada’s food system. Although sustainable production systems and diets are important for human and environmental well-being, there is no silver bullet approach to define the trade-offs that exist between environmental health, human health, economic feasibility and cultural appropriateness of the Canadian diet. There is a need for dieticians, environmental/agroecosystem scientists and policy makers to work together to inform public education and policy initiatives using science-based information to ensure nutrient adequacy, improve health and ensure the environmental sustainability of Canadian diets. However, as we support consumers in their quest to make informed choices regarding diet, we must be mindful there is room in the marketplace for a variety of production systems.


Published in the proceedings of the Animal Nutrition Conference of Canada 2020. For information on the event, past and future editions, check out

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