China’s livestock transition: Driving forces, impacts, and consequences

China’s livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs). Changes were fueled through increases in demand as well as, supply of new breeds, new technology, and government support. Production of animal source protein increased 4.9 times, nitrogen use efficiency at herd level tripled, and average feed use and GHG emissions per gram protein produced decreased by a factor of 2 between 1980 and 2010. In the same period, animal feed imports have increased 49 times, total ammonia and GHG emissions to the atmosphere doubled, and nitrogen losses to watercourses tripled. As a consequence, China’s livestock transition has significant global impact. Forecasts for 2050, using the Shared Socio-economic Pathways scenarios, indicate major further changes in livestock production and impacts. On the basis of these possible trajectories, we suggest an alternative transition, which should be implemented by government, processing industries, consumers, and retailers. This new transition is targeted to increase production efficiency and environmental performance at system level, with coupling of crop-livestock production, whole chain manure management, and spatial planning as major components

Role of livestock in circular bioeconomy systems

Implications A circular bioeconomy integrates both bioeconomy principles and circular principles to create sustainable, low-impact solutions that ensure efficient use of biological resources. Livestock play an important role in a circular bioeconomy as they enable the upcycling of agricultural products unsuitable for consumption by humans into nutritionally rich animal-sourced foods, and their excrements serve as valuable organic fertilizer. Understanding positive and negative environmental impacts of livestock production systems is the key to establishing a sustainable circular bioeconomy

Simulating grazing beef and sheep systems

CONTEXT Ruminant livestock make an important contribution to global food security by converting feed that is unsuitable for human consumption into high value food protein, demand for which is currently increasing at an unprecedented rate because of increasing global population and income levels. Factors affecting production efficiency, product quality, and consumer acceptability, such as animal fertility, health and welfare, will ultimately define the sustainability of ruminant production systems. These more complex systems can be developed and analysed by using models that can predict system responses to environment and management. OBJECTIVE We present a framework that dynamically models, using a process-based and mechanistic approach, animal and grass growth, nutrient cycling and water redistribution in a soil profile taking into account the effects of animal genotype, climate, feed quality and quantity on livestock production, greenhouse gas emissions, water use and quality, and nutrient cycling in a grazing system. METHODS A component to estimate ruminant animal growth was developed and integrated with the existing components of the SPACSYS model. Intake of herbage and/or concentrates and partitioning of the energy and protein contained in consumed herbage and/or concentrates were simulated in the component. Simulated animal growth was validated using liveweight data from over 200 finishing beef cattle and 900 lambs collected from the North Wyke Farm Platform (NWFP) in southwest England, UK, between 2011 and 2018. Annual nitrous oxide (N2O), ammonia, methane and carbon dioxide emissions from individual fields were simulated based on previous validated parameters. RESULTS AND CONCLUSIONS A series of statistical indicators demonstrated that the model could simulate liveweight gain of beef cattle and lamb. Simulated nitrogen (N) cycling estimated N input of 190 to 260 kg ha−1, of which 37–61% was removed from the fields either as silage or animal intake, 15–26% was lost through surface runoff or lateral drainage and 1.14% was emitted to the atmosphere as N2O. About 13% of the manure N applied to the NWFP and excreta N deposited at grazing was lost via ammonia volatilisation. SIGNIFICANCE The extended model has the potential to investigate the responses of the system on and consequences of a range of agronomic management and grazing strategies. However, modelling of multi-species swards needs to be validated including the dynamics of individual species in the swards, preferential selection by grazing animals and the impact on animal growth and nutrient flows

Meat matters - making the case for a valuable food in a hostile environment

Contemporary views on meat reflect an ambiguous status of appreciation and rejection, especially in the urbanised West, and tend to come with strong moral overtones. The portrayal of (red) meat as an intrinsically harmful food choice by certain academics, non-governmental organisations, mass media, and public-private partnerships contributes to this tension. Although most of these voices are merely calling for a moderation of the consumption of meat in areas with high intake, others are radical and demand a drastic reduction or even elimination, as will be documented in this article. Some scientists are beginning to articulate their concern about an ongoing trend towards unbalanced communications and anti-meat militancy in both academic and policy circles. The perceived threat is not only that the vilification of meat may add to the ongoing moralisation of dietary choices and societal polarisation, but also that it may further undermine an already precarious situation of public health and a fragile food system, especially (but not only) in the Global South. Minimising livestock may also come with unintended harmful effects on ecosystems and livelihoods. The ‘Dublin Declaration of Scientists on the Societal Role of Livestock’, issued in October 2022, exemplifies such concern. Together with the body of evidence to which it refers, the Dublin Declaration is to be read as a petition for pragmatism, demanding sufficiently high standards of evidence, and more respect for the principle of caution when it comes to policies that have the intention to severely challenge the role of meat and other animal source foods in future diets

Circular bioeconomy: animal by-products from livestock carcass processing

Implications: Livestock carcass production systems (as opposed to dairy and egg production) have as their primary objective to produce meat for human consumption. This production is accompanied by by-products, which are either not consumable by humans or not appreciated (e.g., offals in certain regions). By-products from meat production contain valuable components (e.g., protein, fat, minerals), which may be used by or recycled either directly to humans or in livestock feed, following specific processes (called rendering). Rendered animal by-products can be used to replace other sources of nutrients such as plant-based proteins (e.g., soybean meal), calcium and phosphorus sources (mined sources), fat (e.g., oil from oilseed), maintaining these nutrients within the food chain and improving sustainability via circularity. Advancements in the rendering sector resulting from the Bovine Spongiform Encephalopathy (BSE) crisis have allowed for the safe use of these by-products. However, a higher use of these valuable by-products is required in the context of circular bioeconomy

The effects of dietary saponins on ruminal methane production and fermentation parameters in sheep: a meta analysis

Ruminants production systems are facing a critical period within global agriculture due to their unique digestive system which, whilst allowing them to utilize low-quality fiber-rich feed, produces the potent greenhouse gas methane (CH4) as a by-product. It has been proposed that saponin-rich plants can be used to reduce CH4 emissions from ruminant livestock, although the reported results are variable in terms of efficacy. Here we use meta-analytical methods to investigate the literature to determine if saponins can contribute to reducing CH4 production and its further effects on other rumen fermentation parameters in sheep. Following defined search terms available papers on the subject were collected for the period 1990 to 2019 and inclusion and exclusion criteria were applied, an analysis was conducted on CH4 production, CH4 per dry matter intake (DMI), ruminal pH, total volatile fatty acid (VFA), acetate, propionate, butyrate, and acetate-to-propionate ratio based on a comparison between a saponin supplemented group and a control group. The standardized effect size (Hedges’ g) was calculated at the confidence interval of 95%. Q-test and I 2 statistic were used to determine heterogeneity and publication bias was identified through the Egger test. The meta-analysis determined that using saponin sources tended to decrease CH4 production (P=0.062) and acetate-to-propionate ratio (P=0.057), with a reduction in CH4/DMI (P=0.001) and an increase in propionate concentration (P=0.011). No significant difference was observed in ruminal pH, total VFA concentration, and butyrate concentration. The I 2 statistic for the parameters analyzed here was below 50% for heterogeneity with the Egger test results indicating a publication bias for CH4 production

Data to identify key drivers of animal growth and carcass quality for temperate lowland sheep production systems

With the growing demand for animal-sourced foods and a serious concern over climate impacts associated with livestock farming, the sheep industry worldwide faces the formidable challenge of increasing the overall product supply while improving its resource use efficiency. As an evidence base for research to identify key drivers behind animal growth and carcass quality, longitudinal matched data of 741 ewes and 2978 lambs were collected at the North Wyke Farm Platform, a farm-scale grazing trial in Devon, UK, between 2011 and 2019. A subset of these data was subsequently analysed in a study to assess the feasibility of using a lamb's early-life liveweight as a predictor of carcass quality [1]. The data also have the potential to offer insight into key performance indicators (KPIs) for the sheep industry, or what variables farmers should measure and target to increase profitability

The uptake of selenium by perennial ryegrass in soils of different organic matter contents receiving sheep excreta

Background and aims The intake of selenium, an essential element for animals and humans, in ruminants is largely determined by selenium concentration in ingested forages, which take up selenium mainly from soil. Ruminant excreta is a common source of organic fertilizer, which provides both nutrients and organic matter. This study aims to unentangle the unclear effect of applying different types of ruminant excreta in soils of different organic matter contents on selenium uptake by forage. Methods Perennial ryegrass (Lolium perenne) was grown in soils of different organic matter contents. Urine and/or feces collected from sheep fed with organic or inorganic mineral supplements, including selenium, were applied to the soils. The selenium in the collected samples were analyzed using ICP-MS. The associated biogeochemical reactions were scrutinized by wet chemistry. Results The application of urine and/or feces resulted in either the same or lower selenium concentrations in perennial ryegrass. The excreta type did not affect total selenium accumulation in grass grown in low organic matter soil, whereas in high organic matter soil, feces resulted in significantly lower total selenium accumulation than urine, which was attributed to a possible interaction of selenium sorption in soil and microbial reduction of Se. Conclusion This one-time excreta application did not increase, but further decrease in some treatments, selenium concentration and accumulation in the perennial ryegrass. Consequently, to increase ruminant selenium intake, supplementing selenium directly to animals is more recommended than applying animal manure to soil, which might drive selenium reduction and decrease selenium uptake by grass

Challenges for the balanced attribution of livestock’s environmental impacts: the art of conveying simple messages around complex realities

Meat production is often listed among the largest contributors to climate change, and is usually associated with biodiversity damage, feed-food competition, and water scarcity. This assumption is largely based on the biogenic methane (CH4) emissions of the global herd of ruminants and its occupation of land. Environmental assessments of the livestock sector are all too frequently stated in simplistic terms, making use of a myopic selection of metrics, and overlooking underlying heterogeneity and complexities. One example of such oversimplification is the comparison of the warming effect of different greenhouse gases (CO2, CH4, and N2O), which are associated with a series of challenges due to their own heterogeneous atmospheric ‘behavior’. Whilst useful for certain research questions, standardizations such as the commonly used GWP100 hide many complex issues. These issues include considering different emission profiles of production systems (e.g., low-methane porcine vs. high-methane ruminant), the need to factor in CO2 and CH4 sinks, the different atmospheric lifetimes of each gas and subsequent atmospheric warming potential, and compensatory background emissions in alternative rewilding scenarios. Whilst poorly managed land negatively affects biodiversity, well-managed land strategies, including those pertaining to livestock production, can lead to favorable outcomes (e.g., biodiverse swards that encourage pollination and beneficial microfauna). Similarly, the assessment of water wastage and land use requires contextualized approaches. This highlights the importance of addressing agricultural heterogeneity in systems analysis, including Life Cycle Assessment (LCA). To further reflect the food-environment nexus, nutritional LCA (nLCA) incorporates considerations of food. optimizing e.g. nutritional sustenance and reducing, in theory, the amount of food we consume through meal-level assessment - rather than focusing on a single product.• Being more recent than the wider LCA ‘umbrella’ (e.g., Life Cycle Cost Analyses), one current drawback of nLCA is that it can be easily manipulated to favour one product over another, whether plant- or animal sourced, by singling out specific nutrients (e.g., fiber or vitamin C vs. vitamin B12 or digestible amino acid balanced protein). When considering the value of livestock products against their environmental impact, a holistic assessment is needed using balanced metrics and avoiding tunnel vision. Besides factoring in nutrition and co-product benefits, other natural capitals, and societal assets that result from well-managed farm enterprises need to be acknowledged, even if no empirical metric can currently fully account for their true value. Examples include: biodiversity, soil health, land stewardship, and rural community support; especially in a time of extreme variability due to climate, social unrest, and economic crises

A comparison of conventional and 137 Cs-based estimates of soil erosion rates on arable and grassland across lowland England and Wales

Soils deliver a range of ecosystem services and underpin conventional global food production which must increase to feed the projected growth in human population. Although soil erosion by water and subsequent sediment delivery to rivers are natural processes, anthropogenic pressures, including modern farming practices and management, have accelerated soil erosion rates on both arable and grassland. A range of approaches can be used to assess and document soil erosion rates and, in the case of the UK, these mainly comprise the 137Cs-based approach, conventional surveys using volumetric measurements, integration of information on suspended sediment flux, fine sediment source apportionment and landscape sediment retention and traditional bounded hydrological monitoring at edge-of-field using experimental platforms. We compare the erosion rates for arable and grassland in lowland England assessed by these different techniques. Rates assessed by volumetric measurements are similar to those generated by integrating information on suspended sediment flux, sources and landscape retention, but are much less than those estimated by the 137Cs-based approach; of the order of one magnitude less for arable land. The 137Cs approach assumes an initial distribution of 137Cs uniformly spread across the landscape and relates the sampled distribution to erosion, but other (transport) processes are also involved and their representation in the calibration procedures remains problematic. We suggest that the 137Cs technique needs to be validated more rigorously and conversion models re-calibrated. As things stand, rates of erosion based on the distribution of 137Cs may well overstate the severity of the problem in lowland Britain and, therefore, are not a reliable indicator of water erosion rates