The societal role of meat: the Dublin Declaration with an Australian perspective

In examining how global nutrient supplies from food match up to global population requirements, it is evident that meat contributes the majority of the global vitamin B₁₂ supply (DELTA Model®), as well as a quarter of vitamin A (in retinol equivalents), and high proportions of other B vitamins and several minerals such as iron and zinc, despite meat making up only 7% of global food mass and 11% of global food energy, providing further evidence for its nutrient density (Smith et al. 2022b). Importantly, this global picture does not capture regional variation. In the case of unprocessed red meat, the average per capita daily consumption is estimated at just 7 g in southern Asia, 24 g in Sub-Saharan Africa, 36 g in the Middle East and 45 g in northern Africa. Values are much higher in high-income countries, 51 g globally, 68 g in Latin America and the Caribbean, 87 g in Southeast and eastern Asia, and a sizable 114 g in central or eastern Europe and central Asia (Miller et al. 2022). Regions with the lowest intake also show the highest prevalence of malnutrition (Adesogan et al. 2020; Leroy et al. 2023). For instance, resource-poor countries suffer from a high prevalence of juvenile stunting and other forms of malnutrition, in part due to inadequate dietary diversity and a heavy reliance on a single staple (typically cereal grains) for daily energy needs (Ranum et al. 2014; Leroy et al. 2023).

In many countries of Sub-Saharan Africa and southern Asia where meat intake is very low, and malnutrition is high, animal husbandry is a critical aspect of economic survival as well as nutritional necessity, particularly for the young. These populations could benefit from an increased rather than reduced meat intake (Randolph et al. 2007; Adesogan et al. 2020). A prominent feature of this session was the role of meat as a dietary ingredient for children, pregnant and lactating women, women of reproductive age, older adults, and individuals in low- and middle-income countries (Leroy et al. 2023). Animal-sourced foods, such as meat, are the best source of nutrient-rich foods for children in their first 1000 days (a finding supported by the World Health Organization), leading to normal growth and development and compelling benefits on cognitive functions (Balehegn et al. 2022). Thus, global efforts to moderate meat intake for environmental or other reasons should be careful not to restrict its growth in populations where consumption is already low, as this could hinder progress towards reducing malnutrition and thereby not address human suffering and the stifling of economic development (Wong et al. 2017; Balehegn et al. 2019).

In many regions where there is a lack of animal-sourced food in the diet, the population is also exposed to mycotoxins in their food staples (especially maize and peanuts). Chronic exposure to mycotoxins in developing societies have been shown to significantly affect public health by reducing infant growth and development, causing immunosuppression, and increasing the risk of cancer, especially hepatocellular carcinoma (Wu et al. 2014; Wild et al. 2015; Bryden 2019). Reduced access to animal-sourced foods in these societies will further decrease public health as facilities for food storage are often rudimentary, facilitating fungal growth and mycotoxin production in stored grains. Moreover, in developed countries there is increasing pressure to shift from red meat to plant–based meat analogues. This neglects natural toxin contamination, especially by mycotoxins of these plant products (Mihalache et al. 2022a), as has also been found in plant-based milks (Arroyo-Manzanares et al. 2019) Although reducing meat consumption does decrease some diet-related health risks, the overall risk to health is increased by the consumption of plant-based meat substitutes (Mihalache et al. 2022b). In other surveys, it has been also found that populations that exclude animal-sourced foods from their diets have greater exposure to mycotoxins (Leblanc et al. 2005; Penczynski et al. 2022).

The crucial role of livestock in Africa was outlined by Shirley Tarawali from the International Livestock Research Institute (Baltenweck et al. 2020; Tarawali 2022; Ederer et al. 2023). Some 23% of the world’s cattle are in Africa, supplying about 8% of the world’s meat, contrasting this to the USA and Europe where cattle populations total 6–7%, yet supply 15–18% of the world’s meat, clearly showing the low productivity of the African livestock systems. More broadly, in low- to middle-income countries, 1.7 billion people derive some livelihood from livestock and poultry and over half a billion depend on livestock and poultry. Improving livestock productivity and health in these countries is crucial for sustaining incomes, reducing financial risk, growing wealth to ‘step out’ of poverty, gender equality and of course adequate nutrition (Alders and Pym 2009; Wong et al. 2017; de Bruyn et al. 2020). It was concluded that a concerted global effort was needed to support livestock productivity (and so reduce methane intensity) in low- to middle-income countries to improve the standards of living.

The potential for in vitro or cultured meat production was examined by Paul Wood (Wood et al. 2023). The overall process is to culture muscle cells in bioreactors in highly controlled and sterile conditions similar to those used for growing microbes to produce medical and other products (Bonny et al. 2017; Ellies-Oury et al. 2022). It was concluded that the technology was well established and that cultured meat will appear on the market for consumers. Various private investors have claimed that the cultured-meat scenario will have benefits over livestock, citing lower carbon footprints and environmental damage, plus improved animal welfare due to less animal killing. However, the conclusion was that the technology will never be able to scale at the commodity level to represent a real alternative to traditionally raised meat. Moreover, it will never be a solution to providing high-quality nutrition in low- to middle-income countries.

Similar arguments apply to plant proteins processed to resemble animal-based foods and also referred to as meat substitutes, meat analogues, fake meat, and mock meat (Boukid 2021). It is worth noting that the environmental footprint of plant-based meat substitutes determined from life-cycle analyses may be lower than that of feedlot beef, but higher than that of beef produced on pasture (van Vliet et al. 2020).

Global world food flows were examined by Peer Ederer from GOAL Sciences who have developed a modelling platform called ‘Planet Food System Explorer’ (Ederer et al. 2023; GOAL Sciences 2023). The modelling conclusively shows that, on a global basis, both the cost and supply of calories for humans is theoretically enough to meet world demand if there were equitable distribution. However, the supply of bioavailable protein and nutrient-rich foods is more precarious, with over a third of the world population being unable to afford these nutrients. Animal-sourced foods, especially dairy, poultry and eggs, are very cost-competitive on a world stage. Indeed, the cost of bioavailable, high-quality protein from poultry and eggs is cheaper than the same nutrients derived from cereals, meaning that, from a bioavailable-protein perspective, it is better to feed cereals to chickens than to humans! It was also argued that increasing alternate protein supplies especially from grain legumes has proved problematic due to agronomic difficulties in many climatic and geological scenarios, along with the issue of anti-nutritional compounds that legumes contain. In addition, the view that livestock feed grain competes for human food was shown to be flawed, with, for example, only 5% of the world ruminant diet consisting of grains and 86% of the world livestock being fed non-human-edible products (Mottet et al. 2017; Leroy et al. 2022; Ederer et al. 2023). A troubling trend for competition between animal feed versus petroleum production was also highlighted, adding further constraints on world protein production. Finally, it was concluded by Ederer et al. (2023) that depending on what value is chosen for the average protein requirement per person per day, the world protein supply (from all sources) is either adequate, or needs to expand by up to 80%. If this is projected out to 2050, on the basis of population growth estimates, then global protein supply needs to increase by 20–150% over the current levels. These analyses have highlighted the important role of food production from both animals and crops (Ederer et al. 2023).

The ethics of meat consumption were examined by Candace Croney who asked the following question: ‘Is eating meat morally defensible?’ (Croney and Swanson 2023). While the strength of the scientific argument was based on increased global food demand, historical and cultural prominence, nutritional benefits, increased demand in developing and emerging economies and technological developments that distribute benefits, Croney also discussed the perspective that there can be arguments against meat consumption. Ethics questions are more likely to emerge when science is equivocal and ethics questions are more prevalent when there is affluence and choice; however, ‘public opinion’ is diverse. In other words, distinct differences exist among consumer populations and their perceptions and needs. For affluent countries, food is more than sustenance and reflects values and social justice, with many responding to advocacy groups and others seeking to reduce meat consumption (McKendree et al. 2014). Arguments that meat eating does harm include animal suffering and death, has negative impacts on natural resources, ecosystems and local communities, and aspects of worker health and safety and quality of life. However, these arguments have often been unduly simplified, ignored important stakeholders and have poorly framed arguments (de Bruyn et al. 2020; Thompson et al. 2023). Indeed, as discussed by Leroy et al. (2022), crop production, the basis of a diet that excludes animal products, comes with an animal death toll that may be even higher than that from large-animal husbandry and slaughter. There are strong positive arguments for the environmental sustainability of meat production and the application of the least harm principal (Regan 1983; Davis 2003) indicates that animal welfare will be best served by inclusion of meat from large herbivores in the diet, rather than having diets that exclude animal products. In terms of equitable access to food, many do not have the luxury of choice and should have access to meat, as malnutrition is still prevalent among children and females when access to high-quality proteins and micronutrients is limited. The latter theme was explored in depth at the meeting. Croney and Swanson (2023) concluded that eating meat was morally defensible, as have others (de Bruyn et al. 2020).

Most of Australia’s cattle are grazed in the rangelands of the monsoonal north, part of the 85% of agricultural land where rainfall is usually too low or erratic to support crops or allows only limited pasture improvement. Without livestock, this zone would produce little or no food at all and the plant resources growing there would not contribute to feeding people inside and outside of the country. The value of grazing is best demonstrated through calculation of net protein contribution (NPC) for a grazing system (Box 2). NPC represents the amount of human-edible protein produced, divided by the amount of human-edible protein consumed by the animal (both produced and consumed, adjusted for amino acid value). In a grazing system that uses a small amount of human-edible protein for feed supplements, an NPC of 1597 has been calculated, that is, 1597 kg human-edible protein produced for every kilogram consumed (Thomas et al. 2021a). It is not a choice between animal and plant protein production, but between animal protein and no protein/food production at all.

In northern Australia, the quality of native pastures is usually low. High rainfall and leaching keep essential nutrients, especially nitrogen, low in the soil profile, and plants are, therefore, usually low in protein. Due to its fragile environment, it has been recognised for many years that it is an area that must be carefully managed (Ferguson 1973). The wet, monsoonal-zone native pastures have high levels of structural carbohydrates, high cellulose and lignin contents, and low digestibility (Minson 1990; Charmley et al. 2023), making it difficult for livestock to obtain sufficient energy for rapid growth. Many of the soils of northern Australia are low in phosphorus, and the plants usually have also low phosphorus content and phosphorus deficiency of cattle is prevalent without supplementation (Dixon et al. 2017; Schatz et al. 2023). Less than 5% of the pastures in these regions have been improved with fertilisers and introduced pasture species. Expenditure on fertiliser for large and medium beef properties in northern Australia has been low to negligible (Lean et al. 2011). The advantages of the extensive pastoral system are the low cost of pasture, while the disadvantage is the great variability in pasture production reflected in a marked variation in growth and development of animals.

The northern pastoral zone is characterised by low-cost pasture and cyclic forage variability. The major constraints to production are under-nutrition, both in amount and quality of feed, costs of management inherent to such extensive properties, and heat stress and parasites and disease (Bell and Sangster 2023). Poppi and McLennan (1995) reviewed major limitations to the beef production system arising from deficiencies in the energy and protein content within the dominant pastures of the northern beef industry and explored the interactions among these major nutrients. These limitations are often expressed in poor reproductive efficiency (see McGowan et al. (2014); this report has since been published in 2023 in a series of papers in Animal Production Science 63 issue 4).

Cyclic weight gain and loss that reflects the annual change in pasture quality and quantity, resulting in a low efficiency of production, is a characteristic of the system. However, Lean et al. (2011) reviewed 40 years of published weight-gain data from northern Australia and identified substantial variations (>1 kg/day difference) in the performance of the cattle on native pastures and further identified substantial (>70% improved weight gain) responses in some cases to supplementation. Bell and Sangster (2023) reviewed the substantial benefits from use of improved agronomic approaches to increase weight gains, including increased adoption and management of Stylosanthes species, Leucaena, Desmanthus cv and other tropically adapted legumes. These findings indicate the potential for the northern beef system to be more productive.

Stocking rates are often extremely low in the pastoral zone, with many hectares being allocated to a single animal (Tothill and Gillies 1992). The latter observation stresses the importance of grazing management under conditions where the energy loss from exercise during grazing or obtaining water will become significant determinants of performance. Bell and Sangster (2023) noted the extreme conditions of the pastoral zone and especially the Northern Forest and the very poor reproductive performance there (McGowan et al. 2014). These factors do lead to low energy-use efficiency (Hunter 2010); however, the key metric that indicates the merit in the pastoral system is that there are very little, to zero, human available nutrients used in this production system to produce beef, unless finished in feedlots, as discussed below.

Most of the agricultural land with modified or improved pastures and crops is part of the mixed farming zone. Most farms retain a mix of crops and livestock because together they are far more efficient in the production of food than is either separately. Crops can benefit the production of meat and wool without compromising the yield of crops for food production. For example, there is a rapidly increasing trend to graze crops in the vegetative stage (Radcliffe et al. 2012). Such crops have a high metabolisable energy (>12 MJ ME/kg DM) and protein content (>20% DM) suitable for pregnant or rapidly growing ruminants (Masters and Thompson 2016) and allow establishment of pastures through deferred grazing (Thomas et al. 2015). Provided grazing ceases before stem elongation, the yield of harvested grain is usually maintained (Harrison et al. 2011). Grazing young crops without loss in grain yield facilitates animal production, with no trade off in the production of food from plants. At the other end of the crop-growth cycle, a single hectare of post-harvest wheat residue provides sufficient metabolisable energy to support one dry sheep equivalent for 50–100 days (Thomas et al. 2021b). If retained, this stubble may decrease subsequent crop yield (Kirkegaard 1995); conversely, loss of stubble through burning and conventional tillage may increase susceptibility to erosion and soil carbon depletion (Chan et al. 2003; Chan and Heenan 2005). The implications of grazing are less clear, with some evidence from overseas that the mixing of stubble residue in soil caused by livestock trampling compensates for the loss of stubble from consumption, with a consequent increase the soil organic carbon (Stavi et al. 2016). Soil compaction due to grazing stubble was once considered a risk to crop production. This risk is no longer supported by the literature (Bell et al. 2011b). Grazing therefore offers another opportunity to convert a crop waste product into food or fibre, with 3–6.5 million ha of crop residue grazed annually (D. T. Thomas, pers. comm.). Finally, livestock offer opportunities to turn failed crops into food (Bell et al. 2009). When the cost of harvesting crops that have been constrained by low rainfall, poor soils or other external factors exceeds the financial return, grazing provides a means of turning a financial loss into an animal product.

Crops do not just provide an option for increasing livestock production, they can also benefit from the interaction, meaning more efficient production of plant-based food. Traditionally, legume pastures have been used in rotation with crops, providing grazing while simultaneously fixing nitrogen, improving soil structure and contributing to the management of weeds, pests and disease (Bell et al. 2019). Other cropping options such as canola have joined the rotations, facilitated by the availability of cheap nitrogen fertilisers; pastures have been displaced and degraded (Howieson et al. 2000). With increasing fertiliser prices, expansion of acid soils and widespread herbicide resistance, there has been a refocus on breeding new pasture options for livestock and crop benefits (HC Norman and DG Masters, Livestock preference and feeding value as key determinants for forage improvement – why not ask the consumer? Animal Production Science, under review).

More than 3.5 million head of cattle were turned off from Australian feedlots in 2022 (Atkinson 2022), representing a 100% increase in numbers over 20 years (Spragg 2018). Many of the 400 feedlots are sited close to the grain-producing regions of Australia, because costs of transport greatly increase the costs of feed and reduce the cost efficiency for those further away from grain-growing regions. Feedlot systems rely on a markedly different efficiency of conversion of feed intake to beef from cattle fed on either northern or southern pastures to be cost-effective. Typically, finishing diets for feedlot cattle contain 80–85% of concentrates, with processed grains, protein meals, molasses, minerals and feed additives and by-products being combined in mixer-wagons with 10–20% of forages, including cereal crop and maize silages, hays and straws, the latter being by-products of grain production. Spragg (2018) reviewed grain use in Australia for the 2017/2018 and 2018/2019 financial years, with wheat and barley being the predominant products (88% of all grain produced). Overall, grain fed to animals was about 30% of national production, with dairy and beef feedlots (48%) and chicken meat and eggs (31%) accounting for nearly 80% of feed grain usage. While it has been argued that feedlot systems are inefficient because the grain use would be better fed to humans, a large proportion of the grain used in feedlots, and indeed animal nutrition in Australia, is at the lower end of quality standards with respect to suitablility for human consumption and often just classified as feed grain, based on cultivar (e.g. sorghum, non-malting barley) and physical characteristics such as rain-damage and suboptimal specifications (Anonymous 2009, 2020, Black et al. 2023). More importantly, there is evidence of an NPC >1 (1.96), even when cattle are finished within a feedlot and fed a cereal-based ration with a significant amount of human-edible protein (Thomas et al. 2021a). The production system, combining grazing and feedlot, results in a net increase in human-edible protein. Further, beef and dairy cattle are fed by-products of ethanol production, human food production and cotton production. These products include dried distillers’ grains, wheat by-products from flour manufacture, including wheat mill run and middlings, canola meal, sunflower meal, and whole cottonseed. Alternate uses for many of these products are limited and the use of these in cattle production lowers the costs of production for ethanol, flour, bread, processed wheat products, cooking oils and cotton.

Cattle for the local market are often fed for approximately 70 days in the feedlot, those for export and premium local markets 100–120 days and those for speciality long-fed markets, particularly Wagyu cattle, 200–230 days or more. In terms of GHG, many feedlot cattle are fed ionophores that reduce methane production (Ranga Niroshan Appuhamy et al. 2013), and the shorter time to slaughter than for growing cattle on pasture has a marked reduction in methane per kilogram of beef (methane intensity). The use of feedlots to finish cattle from the northern pastoral system represents a profound increase in GHG efficiency over traditional finishing at a much older age.

There are 1.4 million dairy cows in Australia and a similar number of young cattle, heifers and calves in the national dairy herd (Australian Bureau of Agricultural and Resource Economics and Sciences 2022b). Milk production per cow has increased from 2848 to 6170 L per annum over the 40 years to 2020. This change has significant effects on GHG emissions intensity as the proportion of methane ascribed to maintenance is reduced. Over this time, the industry has changed from being seasonal and pasture-based (Lean 1987) to less seasonal and with greater reliance on a wide range of fodder crops, feed supplements and concentrate inputs (Rugoho et al. 2017). Victorian farms evaluated for the Dairy Farm Monitor fed 61% of the metabolisable energy consumed as homegrown forages (Anonymous 2021). The forages used are almost exclusively improved and ryegrass species dominant, especially in southern Australia. Legume forages, predominantly clovers and also lucerne, are used. Other grasses include fescues, paspalum, kikuyu and there is increased use of maize silage. Herbs including chicory and plantain are used in mixed swards. Dairy cattle make great use of the by-products noted previously, but also brewers’ grains, vegetable and fruit waste, confectionary, bread and biscuit waste. Spragg (2018) estimated the use of feed grain as 2.63 million tonnes for dairy in Australia. Beef is produced from dairy cattle with a high level of efficiency due to the reduced contribution to maintenance ascribable to the dual purpose of the cattle. Specifically, a beef female is not required to produce the calf. Increased use of sexed semen will allow increased production of beef semen on dairy cattle to produce crossbred cattle; however, Holstein steers are extensively used for beef production in the USA and Australian studies have confirmed that their eating quality matches that of beef breeds (Polkinghorne et al. 2023a).

In Australia, there is little human-edible food used to produce beef and milk. Many of the essential nutrients provided in beef and milk have zero human-edible food inclusion and this is the case for grass-finished beef. Using worst-case scenarios, that is assuming all grain fed was edible by humans, Lean and Moate (2021) found that 0–28% of lifetime nutrient intakes of energy, protein and essential fatty acids were derived from human-edible sources. As shown in previous examples, feeding these small amounts of human-edible foods to animals may leverage a net increase in human-edible protein (Thomas et al. 2021a). Cattle provide an efficient and productive means of turning human-inedible grain and food and ethanol by-products into high-quality foods, thereby reducing the costs of food overall and oxidation and gas generation from these wastes.

The pig and poultry industries have grown exponentially over the past 60 years as local demand for meat (chicken and pork) and eggs has increased, but are small compared with their global counterparts. Each industry in Australia is dominated by a few large companies and the number of farms in each industry has decreased significantly over time. The large companies have adopted a vertically integrated structure and this has facilitated intensification and allowed rapid adoption of new technology. Each industry has sought the best technology from around the world and invested heavily in research and this has resulted in the acquisition of superior genetics, improved nutrition, better disease control, more effective management practices, and improved animal welfare. Together, these have resulted in significant gains in animal performance and feed conversion, boosting overall industry efficiency and productivity.

Australian breeding sow numbers are approximately 265 000, producing 5.2 million pigs annually. Most pigs are sold at bacon weight (100 kg), with a dressed carcass weight of 77 kg, resulting in 420 000 tonnes of pig meat produced annually (Dalgleish and Whitelaw 2021). The major pig production areas are in south-eastern Queensland, southern New South Wales (NSW), northern and western Victoria, south-eastern South Australia, and south-western Western Australia. Farrow to finish is the conventional structure of Australian pig farms and in this system, the farm breeds, farrows, weans and grows out pigs for sale. Production in Australia is largely confined to intensive indoor housing systems, with only 10% of commercial breeding as free range. The Australian production system is focused on the fresh pork market as this product has little competition from the import market of processed meat where 160 000 million tonnes is imported annually, or about 30% of total pig meat use in Australia (Spragg 2018). Currently, 42 000 tonnes are exported from Australia annually (Spragg 2018).

With approximately 600 million broilers producing ~1.2 million tonnes of chicken meat annually, Australia has mirrored the increased global demand for chicken meat (RMCG and BDO EconSearch 2020). Major centres of chicken meat production have developed near major capital cities on the eastern seaboard. Approximately 800 growers produce about 80% of Australia’s meat chickens under contract to the major integrated or processing companies. Contract growers own the farm and provide the management, shedding, equipment, labour, bedding and other inputs to rear chickens from day-old to processing. The processing company provides (and owns) the chickens and provides feed, medication, and technical advice. Australian chicken meat is sold wholly into the domestic market, with some 70% being sold as fresh chicken (RMCG and BDO EconSearch 2020). Supermarkets represent the largest distribution channel, selling 40% of the fresh chicken meat. A very small volume of chicken meat is exported (4%). Chicken meat cannot be imported into Australia, to keep the industry free of major avian diseases. The excellent disease status of Australian poultry is maintained by strict biosecurity measures that exclude importation of poultry meat. This also has the effect of eliminating competition from chicken meat imports.

Australia’s annual egg production is currently 6.6 billion eggs, with a flock size of approximately 21.2 million laying hens (AEL 2022). The industry is dominated by large-scale producers, who sell directly to large retail sellers. As with the chicken meat industry, commercial egg farms are situated close to the major cities, but, in recent years, the industry has re-established near major regional centres. Most of the flocks are found in NSW, followed by Queensland then Victoria, with eggs being produced by birds housed in cages (31.1%), free-range (55.6%), barn (11.3%) or speciality production (2.0%) (AEL 2022). About 85% of eggs are sold into the domestic market, with export being limited by production and transport costs (AEL 2022).

Profitability of the non-ruminant industries is driven by feed efficiency, the cost of feed, genetic improvement, animal/bird health status, and, for the pig industry, competition from imported pig meat. Feed-related expenses comprise 60–70% of total production costs, thus minimisation of feed costs is very important. This is in part achieved by least-cost feed formulation, which allows incorporation into diets of ingredients such as millrun, a co-product of flour milling, oil seed meals that are the residues of vegetable oil manufacture, and feed grade grains or grains that do not meet the criteria for human food manufacturing. For example, in 2021, some 45% of the NSW wheat harvest was downgraded to feed-wheat due to preharvest germination and fungal deterioration (Black et al. 2023). Where grains suitable for human consumption are used, they usually facilitate the conversion of a range of non-human edible by-products and food waste into human-edible protein. In the pig industry, for example, the NPC for an intensive Australian pork supply chain has recently been reported as 3.26, indicating the production of 3.26 times more human-edible protein than is consumed (van Barneveld et al. 2023). The authors are unaware of similar studies for the chicken meat and egg supply chains. Both the pig and poultry industries have become increasingly successful at using co-product meals by incorporating speciality feed additives into diets to improve digestibility with feed enzymes and dietary amino acid balance with supplementary amino acids (Ravindran 2013; Kebreab et al. 2016). These feed additives not only improve feed utilisation but substantially reduce emissions (Kebreab et al. 2016). Moreover, it is often asserted that land used for producing animal feed, especially for cereal grains, could be used to produce human food, such a transition may not be feasible as humans usually require different crops or cultivars that have different agronomic features and require different environmental conditions (Owens and Hansen 2011).

The other major strategy to offset feed costs is to increase production efficiency. For example, the laying rate of hens has increased from about 161 to 320 eggs per year from 1973 to 2016. Number of piglets weaned per litter and number of litters per sow per year have gradually increased, with sows currently producing 23.6 pigs/year (Dalgleish and Whitelaw 2021). The pig industry is less resilient to increases in feed costs than are the chicken meat and egg industries, due competition from imported pig meat. Chicken meat obviously has a significant cost advantage to other meats as the price of chicken has remained relatively constant for many years, reflecting efficiency of feed conversion which has improved from 2.5 in 1975 to 1.6 in 2020 (ACMF 2022). In achieving improvements in productivity the pig, chicken and egg industries do not use hormones or antibiotics as growth promoters.

In the extensive pastoral regions, careful management of stocking rates to prevent overgrazing can contribute to the maintenance of biodiversity. There is the opportunity for increased soil carbon sequestration through increased growth of pastures, woody shrubs, weeds and trees, emphasising that the animal and, indeed, all the agricultural industries need to adopt net-emissions metrics (Mayberry et al. 2018). Lam et al. (2013) found that conversion of cropland to grazing increased soil carbon more than did conservation tillage, crop residue retention or nitrogenous fertiliser application over 31–40 years. There is also the opportunity to reduce carbon loss through reduced burning of grasslands and increased carbon sequestration in soil using dung beetles (Mayberry et al. 2018). Altering land use management to increase reforestation, reduce savanna burning practices, reduced deforestation, and, to a lesser extent, increase woody biomass growth were considered likely to have the most substantial effects in mitigating the effects of beef cattle production on GHG emissions in Australia (Mayberry et al. 2018). It also appears likely that such strategies would further enhance the benefits of beef production in maintaining biodiverse habitats. Such management options are consistent with the conclusions of others (Masters et al. 2010; Thompson et al. 2023) that well managed animal systems can convert large quantities of non-edible biomass to high-quality foods, while providing diversity and respecting ecological principles that offer ecosystem services.

The introduction of annual crops and pastures into a landscape previously dominated by perennial plants has led to a level of degradation and dysfunction. Most notable is the prevalence of acid soils, the spread of secondary salinity and erosion of unprotected soils following plant senescence. While overgrazing and annual pastures have contributed to these problems, a well managed livestock component to a mixed farm offers opportunities to address the problems. Salinity results from elevated water tables related to a lack of growing plants for much of the year. There are options to use salt-tolerant perennial plants in saline areas or other perennials in non-saline areas to manage the water table (Masters et al. 2006). Both these options can be used for livestock, but there are not yet any viable perennial crops available for this purpose. The introduction of a mosaic landscape suitable for crops and plants offers a landscape with a function more closely resembling the natural state.

Given that sustainability also includes economic viability to the farm or enterprise, there has been a move towards higher cropping intensity in the mixed farming zone, with some evidence of increased profitability (Kingwell et al. 2020); however, there is also recent economic analysis, based on whole-farm profit of mixed enterprises, indicating that the optimal cropping proportion of the farm is between 40% and 60% (Young et al. 2020), with livestock occupying a significant proportion of the land. Together with the higher whole-farm profitability described by Young et al. (2020), there is strong evidence that a mixture of cropping and livestock reduces the risk of income variability. From a study of six sites within the mixed farming zones across four states, Bell et al. (2021) concluded that the risk-efficient frontier included a mix of crops and livestock at most sites. Significantly, this study assessed the risks when the crop and livestock enterprises were run independently and did not take into account the production synergies (Bell et al. 2021).

The carbon footprint of dairy largely reflects enteric methane production from cattle (70%), by nitrogen use for crop and pasture growth (3.5%), methane from manure (13%) and generation of nitrous oxide from urine (12%; Eckard and Clark 2020). The dairy industry, nationally and internationally, has considerable initiatives towards reducing its environmental footprint (Food and Agriculture Organization of the United Nations and Global Dairy Platform Inc 2019). However, the drive towards increased production efficiency through increased production by increased concentrate use, use of ionophores, fats and oils is the major factor reducing the intensity of GHG production (Eckard and Clark 2020; Lean and Moate 2021). There has been a significant focus on reducing ruminal methane production through use of ionophores, fats and oils, red seaweed, 3-nitrooxypropanol, tannins, essential oils and other interventions (Lean and Moate 2021). The final efficacy and practical choice of products to reduce ruminal methanogenesis as it interacts with production system and diet quality is still under intensive research (Davison et al. 2020). Significant reductions in the GHG footprint are also offered through improved reproductive efficiency, production of beef from dairy cows, increased longevity and nitrogen inhibitors that reduce volatilisation of urinary urea. Initiatives in California have provided evidence that large extensive dairies can become carbon neutral through a combination of co-generation and solar capture (Liu et al. 2021). Application of these techniques should, in combination with increased production efficiency, a focus on animal longevity and further adoption of rumen modification, result in carbon neutrality for many Australian dairies.

The chicken meat, egg, and pig industries have a focus on reducing their environmental footprint in areas such as water management, waste minimisation, re-use and recycling, and reduction of greenhouse-gas output. Larger piggeries use methane gas to generate power for their facilities and sell surplus to the local power grid. It has been shown that the pig (Wiedemann et al. 2016, 2018) and chicken meat (Wiedemann et al. 2017; Copley and Wiedemann 2023) and egg (Copley et al. 2023) industries have had success in reducing their footprints. The largest impact that these industries have on the environment is growing the crops that are used for animal feed. Australia produces about 31.2 million tonnes of grain (wheat, sorghum, barley, oats, maize, lupins, and field peas, excluding canola and cottonseed), of which some 37% is used for domestic purposes (feed grain, flour grain, malting grain and retained seed; Spragg 2018). Of the 13.5 million tonnes of feed grain used by the animal industries, meat chickens (24.1%), laying hens (7.4%), and pigs (12.1%) consume some 5.9 million tonnes (Spragg 2018). The non-ruminant industries have reduced their reliance on imported soybean meal by increasing the concentrations of co-products and other protein meals, especially canola, in diets. There is growing interest in the use of human food wastes (Torok et al. 2022) and insect protein meals (de Souza-Vilela et al. 2019; DiGiacomo et al. 2019) as quantities become commercially available. This reduced reliance on traditional feedstuffs will reduce the environmental footprint of feed. Nevertheless, poultry production was shown to have the least environmental impact of all animal-sourced food, largely due to the efficiency of broiler chickens in converting feed into meat, which reduces the amount of feed and therefore the resources of land and water, required to produce each kilogram of meat (Copley and Wiedemann 2023).

The impact of animal production on freshwater resources is an additional challenge for the sustainability of the animal industries. It is particularly important in Australia, the world’s driest continent. Globally, water is scarce and water-use assessment methods have been developed to measure water use by different commodities, communities and countries (Chapagain and Tickner 2012; Boulay et al. 2021). Calculating the water footprint is complex and varies with region, production system, and the type of water used (e.g. blue, green, grey or virtual; see Box 2). Estimates of the water footprint for animal production includes the water consumed by the animal, water used to grow crops for feed, and water required for meat (product) processing. The major component of water use for animal sourced foods is for crop production, especially irrigation (Ibidhi and Ben Salem 2020). In Australia, where most animal feed, both grains and forages, is produced by dry-land farming, water use is minimal compared with production systems in Europe and the USA, where there is much greater reliance on irrigation. Water-use comparisons of the same commodity produced in different production systems can be made only when there is complete transparency of the values used and their derivation. Recently, there has been a conscious effort internationally to build a consensus on water-use methodology for livestock production systems (Boulay et al. 2021).

Some systems of accounting for water use include rainfall and the rainfall used to produce crops such as grain. Depending on the method used to calculate water use to produce 1 kg beef, estimates range from 3 to 540 L of water by using the life-cycle approach to 10 000–200 000 L of water by using a water-footprint approach (which includes rainfall; Doreau et al. 2012). Moreover, when a detailed assessment was conducted over six different beef growing regions of NSW, very different water footprints were obtained by Ridoutt et al. (2012), demonstrating the importance of local geography and confirming earlier Australian results (Peters et al. 2010). A similar result was also obtained when beef cattle production was compared among different regions of South Africa (Harding et al. 2017). It has also been established that as animal productivity and management improve, water-use efficiency of cattle increases (Klopatek and Oltjen 2022). Chicken meat requires the lowest amount water per kilogram produced, reflecting the efficiency of broilers turning feed into meat (Copley and Wiedemann 2023). Regardless, water use is always higher in the production of animal products than of crop products when expressed per kilogram of product. Nevertheless, when examining water data, beware of generalisations when comparing countries and products, which can be demonstrably misleading.

Across large areas of inland Australia, water is supplied to livestock by artesian bores. There has been considerable waste of water from these free-flowing bores, but recent capping of many of these bores has significantly reduced water losses (Wiedemann et al. 2015). Importantly, the extensive livestock systems in Australia generate products by using rainfall on land that is not suitable for other purposes (Doreau et al. 2012); hence, this valuable water resource is captured and not lost. Should this livestock system be penalised for using rainfall in this instance? Water is a precious resource and the interaction between livestock and water needs should be considered for each production system.

Australian animal industries have a social and ethical obligation to deliver demonstrable animal welfare improvements as has been clearly demonstrated (Hemsworth 2018; Salvin et al. 2020; Rivero and Lee 2022; Verdon 2022; Masters et al. 2023). Animal welfare is a key priority for government, industry and research (Barnett and Hemsworth 2009; Hemsworth et al. 2015; Colditz and Hine 2016; Kahn et al. 2017; Tilbrook and Ralph 2017; Colditz 2022). The industries endorse and abide by the relevant Australian Codes of Practice for the Welfare of Animals, and relevant State animal welfare legislation that cover production, transport and slaughter. Nevertheless, Australian producers in all animal industries are under a degree of pressure from animal welfare lobby groups and the public (Bray et al. 2017; Coleman 2018).

Australia is a dry and hot continent and alleviation of heat stress is a welfare issue, as is the long-distance transport of livestock. Mitigating the risk of heat stress in a feedlot is a welfare priority (Johnson 2018). By 2014, community pressure on the feedlot industry and production benefits led to ~80% of feedlots providing shade (Gaughan and Sullivan 2014). In the pig and poultry industries, community pressure associated with confinement of animals has been intense and this has resulted in significant changes. A decade ago only 10% of table eggs were produced free-range, with the remainder being produced by hens housed in cages. Half the table eggs produced in Australia now come from free-range production systems. Although this gives the impression of improved bird welfare, there are concerns regarding choke following pasture consumption and increased exposure to parasites (Bryden et al. 2021; Campbell et al. 2021). It should be remembered that broilers or meat chickens are predominantly housed in large barns and have never been grown in cages. Moreover, some 70% of broilers are farmed under an RSPCA-approved system, including 20% as free-range. The pig industry discontinued the use of dry sow stalls in 2017 and moved to group housing for pregnant sows. The pig industry would like to move away from farrowing crates that prevent piglets being crushed by the sow, but despite ongoing research, no satisfactory alternative has been identified that accounts for the conflicting needs of the sow and her litter (Barnett et al. 2001; Johnson and Marchant-Forde 2009).

There is a general acceptance that improving welfare also improves animal productivity through improved health and reduced medication and mortality (Dawkins 2017), improving the public image of the industries. Moreover, the cost of not maintaining a social licence to operate could be substantial, as it has been estimated that during the period 2015–2030, the potential accumulated loss could amount to A$3.9 billion for the Australian red meat industries (Fernandes et al. 2021). Good stockmanship is a cost-effective way of improving productivity and product quality (Barnett and Hemsworth 2009; Hemsworth 2018). It is an ongoing imperative that all livestock industry personnel are appropriately trained in animal husbandry and stockmanship to ensure animal welfare (Grandin 2018).