Hyperketonemia (HYK) is one of the most frequent and costly metabolic disorders in high-producing dairy cows and its diagnosis is based on β-hydroxybutyrate (BHB) concentration in blood. In the last 10 years, the number of papers that have dealt with the impact of elevated BHB levels in dairy cattle has increased. Therefore, this paper reviewed the recent literature on BHB concentration in blood and milk, and its relationships with dairy cow health and performance, and farm profitability. Most studies applied the threshold of 1.2 mmol/l of BHB concentration in blood to indicate HYK; several authors considered BHB concentrations between 1.2 and 2.9 mmol/l as subclinical ketosis, and values ⩾3.0 mmol/l as clinical ketosis. Results on HYK frequency (prevalence and incidence) and cow performance varied according to parity and days in milk, being greater in multiparous than in primiparous cows, and in the first 2 weeks of lactation than in later stages. Hyperketonemia has been associated with greater milk fat content, fat-to-protein ratio and energy-corrected milk, and lower protein and urea nitrogen in milk. The relationships with milk yield and somatic cell count are still controversial. In general, HYK impairs health of dairy cows by increasing the risk of the onset of other early lactation diseases, and it negatively affects reproductive performance. The economic cost of HYK is mainly due to impaired reproductive performance and milk loss. From a genetic point of view, results from the literature suggested the feasibility of selecting cows with low susceptibility to HYK. The present review highlights that milk is the most promising matrix to identify HYK, because it is easy to sample and allows a complete screening of the herd through BHB concentration predicted using mid-IR spectroscopy during routine milk recording. Further research is needed to validate accurate and convenient methods to discriminate between cows in risk of HYK and healthy animals in field conditions and to support farmers to achieve an early detection and minimise the economic losses.

This paper discusses the sustainability of livestock systems, emphasising bidirectional relations with animal health. We review conventional and contrarian thinking on sustainability and argue that in the most common approaches to understanding sustainability, health aspects have been under-examined. Literature review reveals deep concerns over the sustainability of livestock systems; we recognise that interventions are required to shift to more sustainable trajectories, and explore approaches to prioritising in different systems, focusing on interventions that lead to better health. A previously proposed three-tiered categorisation of ‘hot spots’, ‘cold spots’ and ‘worried well’ animal health trajectories provides a mental model that, by taking into consideration the different animal health status, animal health risks, service response needs and key drivers in each system, can help identify and implement interventions. Combining sustainability concepts with animal health trajectories allows for a richer analysis, and we apply this to three case studies drawn from North Africa and the Middle East; Bangladesh; and the Eastern Cape of South Africa. We conclude that the quest for sustainability of livestock production systems from the perspective of human and animal health is elusive and difficult to reconcile with the massive anticipated growth in demand for livestock products, mainly in low- and middle-income countries, as well as the aspirations of poor livestock keepers for better lives. Nevertheless, improving the health of livestock can contribute to health sustainability both through reducing negative health impacts of livestock and increasing efficiency of production. However, the choice of the most appropriate options must be under-pinned by an understanding of agro-ecology, economy and values. We argue that a new pillar of One Health should be added to the three traditional sustainability pillars of economics, society and environment when addressing livestock systems.

Social and health care provision have led to substantial increases in life expectancy. In the UK this has become higher than 80 years with an even greater proportional increase in those aged 85 years and over. The different life stages give rise to important nutritional challenges and recent reductions in milk consumption have led to sub-optimal intakes of calcium by teenage females in particular when bone growth is at its maximum and of iodine during pregnancy needed to ensure that supply/production of thyroid hormones to the foetus is adequate. Many young and pre-menopausal women have considerably sub-optimal intakes of iron which are likely to be associated with reduced consumption of red meat. A clear concern is the low intakes of calcium especially as a high proportion of the population is of sub-optimal vitamin D status. This may already have had serious consequences in terms of bone development which may not be apparent until later life, particularly in post-menopausal women. This review aims to examine the role of dairy foods and red meat at key life stages in terms of their ability to reduce or increase chronic disease risk. It is clear that milk and dairy foods are key sources of important nutrients such as calcium and iodine and the concentration of some key nutrients, notably iodine can be influenced by the method of primary milk production, in particular, the iodine intake of the dairy cow. Recent meta-analyses show no evidence of increased risk of cardiovascular diseases from high consumption of milk and dairy foods but increasing evidence of a reduction in the risk of type 2 diabetes associated with fermented dairy foods, yoghurt in particular. The recently updated reports from the World Cancer Research Fund International/American Institute for Cancer Research on the associations between dairy foods, red meat and processed meat and various cancers provide further confidence that total dairy products and milk, are associated with a reduced risk of colorectal cancer and high intakes of milk/dairy are not associated with increased risk of breast cancer. Earlier evidence of a significant increase in the risk of colorectal cancer from consumption of red and particularly processed meat has been reinforced by the inclusion of more recent studies. It is essential that nutrition and health-related functionality of foods are included in evaluations of sustainable food production.

Ruminant livestock have the ability to produce high-quality human food from feedstuffs of little or no value for humans. Balanced essential amino acid composition of meat and milk from ruminants makes those protein sources valuable adjuncts to human diets. It is anticipated that there will be increasing demand for ruminant proteins in the future. Increasing productivity per animal dilutes out the nutritional and environmental costs of maintenance and rearing dairy animals up to production. A number of nutritional strategies improve production per animal such as ration balancing in smallholder operations and small grain supplements to ruminants fed high-forage diets. Greenhouse gas emission intensity is reduced by increased productivity per animal; recent research has developed at least one effective inhibitor of methane production in the rumen. There is widespread over-feeding of protein to dairy cattle; milk and component yields can be maintained, and sometimes even increased, at lower protein intake. Group feeding dairy cows according to production and feeding diets higher in rumen-undegraded protein can improve milk and protein yield. Supplementing rumen-protected essential amino acids will also improve N efficiency in some cases. Better N utilization reduces urinary N, which is the most environmentally unstable form of excretory N. Employing nutritional models to more accurately meet animal requirements improves nutrient efficiency. Although smallholder enterprises, which are concentrated in tropical and semi-tropical regions of developing countries, are subject to different economic pressures, nutritional biology is similar at all production levels. Rather than milk volume, nutritional strategies should maximize milk component yield, which is proportional to market value as well as food value when milk nutrients are consumed directly by farmers and their families. Moving away from Holsteins toward smaller breeds such as Jerseys, Holstein-Jersey crosses or locally adapted breeds (e.g. Vechur) would also reduce lactose production and improve metabolic, environmental and economic efficiencies. Forages containing condensed tannins or polyphenol oxidase enzymes have reduced rumen protein degradation; ruminants capture this protein more efficiently for meat and milk. Although these forages generally have lower yields and persistence, genetic modification would allow insertion of these traits into more widely cultivated forages. Ruminants will retain their niches because of their ability to produce valuable human food from low value feedstuffs. Employing these emerging strategies will allow improved productive efficiency of ruminants in both developing and developed countries.

To improve production efficiency, the sheep meat industry has increased flock prolificacy. However, multiple-born lambs have lower birth weights, increased mortality and reduced growth rate compared with single-born lambs. Lamb mortality is a major issue for livestock farming globally and solutions are required to increase survival to realise the value of increased flock fecundity. Nutrition during gestation can influence maternal–foetal placental nutrient transfer and thus foetal growth and organ/tissue development, as well as improve postnatal productivity. This review covers the challenges and opportunities associated with increased prolificacy, highlights gaps in our knowledge and identifies some opportunities for how targeted intervention with specific nutrients during mid-to-late pregnancy may influence lamb survival and productivity with a specific focus on pasture-based systems. This time frame was selected as intervention strategies in short-time windows post-pregnancy scanning and before lambing to improve lamb survival in high-risk groups (e.g. triplets) are likely to be the most practical and economically feasible options for pasture-based extensive farming systems.

The drive to increase the output of animal product in some sectors of ruminant livestock production has led to greater use of feeds such as cereal grains and soyabean meal that are potentially human-edible. This trend has caused concern since, by so doing, ruminants compete not only with monogastric livestock but also with the human population for a limited global area of cultivatable land on which to produce grain crops. Reasons for using potentially human-edible feeds in ruminant diets include increased total daily energy intake, greater supply of essential amino acids and improved ruminal balance between fermentable energy and degradable protein. Soyabean meal, produced on land that has been in arable cultivation for many years can fulfil a useful role as a supplier of undegraded dietary protein in diets for high-yielding dairy cows. However, in the context of sustaining the production of high-quality foods from livestock to meet the demands of a growing human population, the use of potentially human-edible feed resources by livestock should be restricted to livestock with the highest daily nutrient requirements; that is, potentially human-edible feed inputs should be constrained to meeting requirements for energy and protein and to rectifying imbalances in nutrient supply from pastures and forage crops such as high concentrations of nitrogen (N). There is therefore a role for human-edible feeds in milk production because forage-only systems are associated with relatively low output per head and also low N use efficiency compared with systems with greater reliance on human-edible feeds. Profitability on farm is driven by control of input costs as well as product value and examples are given of low-cost bovine milk and meat production with little or no reliance on potentially human-edible feeds. In beef production, the forage-only systems currently under detailed real-time life-cycle analysis at the North Wyke Farm Platform, can sustain high levels of animal growth at low feed cost. The potential of all-forage diets should be demonstrated for a wide range of ruminant milk and meat production systems. The challenge for the future development of ruminant systems is to ensure that potentially human-edible feeds, or preferably human-inedible by-products if available locally, are used to complement pastures and forage crops strategically rather than replace them.

The food-feed competition is one of the complex challenges, and so are the ongoing climate change, land degradation and water shortage for realizing sustainable food production systems. By 2050 the global demand for animal products is projected to increase by 60% to 70%, and developing countries will have a lion’s share in this increase. Currently, ~800 million tonnes of cereals (one-third of total cereal production) are used in animal feed and by 2050 it is projected to be over 1.1 billion tonnes. Most of the increase in feed demand will be in developing countries, which already face many food security challenges. Additional feed required for the projected increased demand of animal products, if met through food grains, will further exacerbate the food insecurity in these countries. Furthermore, globally, the production, processing and transport of feed account for 45% of the greenhouse gas emissions from the livestock sector. This paper presents approaches for addressing these challenges in quest for making livestock sector more sustainable. The use of novel human-inedible feed resources such as insect meals, leaf meals, protein isolates, single cell protein produced using waste streams, protein hydrolysates, spineless cactus, algae, co-products of the biofuel industry, food wastes among others, has enormous prospects. Efficient use of grasslands also offers possibilities for increasing carbon sequestration, land reclamation and livestock productivity. Opportunities also exist for decreasing feed wastages by simple and well proven practices such as use of appropriate troughs, increase in efficiency of harvesting crop residues and their conversion to complete feeds especially in the form of densified feed blocks or pellets, feeding as per the nutrient requirements, among others. Available evidence have been presented to substantiate arguments that: (a) for successful and sustained adoption of a feed technology, participation of the private sector and a sound business plan are required, (b) for sustainability of the livestock production systems, it is also important to consider the consumption of animal products and a case has been presented to assess future needs of animal source foods based on their requirements for healthy living, (c) for dairy animals, calculation of Emission Intensity based on the lifetime lactation rather than one lactation may also be considered and (d) for assessment of the efficiency of livestock production systems a holistic approach is required that takes into consideration social dimensions and net human-edible protein output from the system in addition to carbon and water footprints.

Livestock farming is criticized for negatively impacting the environment, concerns about animal welfare and the impact of excessive meat consumption on human health. However, livestock farming provides other underappreciated and poorly communicated benefits to society in terms of employment, product quality, cultural landscapes and carbon storage by grasslands. Few attempts have been made so far to simultaneously consider the services and impacts provided by livestock production. Here, we propose an integrated graphical tool, called the ‘barn’ to explicitly summarize the synergies and trade-offs between services and impacts provided by livestock farming. It illustrates livestock farming interacting with its physical, economic and social environment along five interfaces: (i) Markets, (ii) Work and employment, (iii) Inputs, (iv) Environment and climate, (v) Social and cultural factors. This graphical tool was then applied by comparing two contrasting livestock production areas (high livestock density v. grassland-based), and the dominant v. a niche system within a crop-livestock area. We showed the barn could be used for cross-comparisons of services and impacts across livestock production areas, and for multi-level analysis of services and impacts of livestock farming within a given area. The barn graphically summarizes the ecological and socio-economic aspects of livestock farming by explicitly representing multiple services and impacts of different systems in a simple yet informative way. Information for the five interfaces relies on available quantitative assessments from the literature or data sets, and on expert-knowledge for more qualitative factors, such as social and cultural ones. The ‘barn’ can also inform local stakeholders or policy-makers about potential opportunities and threats to the future of livestock farming in specific production areas. It has already been used as a pedagogical tool for teaching the diversity of services and impacts of livestock systems across Europe and is currently developed as a serious game for encouraging knowledge exchange and sharing different viewpoints between stakeholders.

Livestock is a major driver in most rural landscapes and economics, but it also polarises debate over its environmental impacts, animal welfare and human health. Conversely, the various services that livestock farming systems provide to society are often overlooked and have rarely been quantified. The aim of analysing bundles of services is to chart the coexistence and interactions between the various services and impacts provided by livestock farming, and to identify sets of ecosystem services (ES) that appear together repeatedly across sites and through time. We review three types of approaches that analyse associations among impacts and services from local to global scales: (i) detecting ES associations at system or landscape scale, (ii) identifying and mapping bundles of ES and impacts and (iii) exploring potential drivers using prospective scenarios. At a local scale, farming practices interact with landscape heterogeneity in a multi-scale process to shape grassland biodiversity and ES. Production and various ES provided by grasslands to farmers, such as soil fertility, biological regulations and erosion control, benefit to some extent from the functional diversity of grassland species, and length of pasture phase in the crop rotation. Mapping ES from the landscape up to the EU-wide scale reveals a frequent trade-off between livestock production on one side and regulating and cultural services on the other. Maps allow the identification of target areas with higher ecological value or greater sensitivity to risks. Using two key factors (livestock density and the proportion of permanent grassland within utilised agricultural area), we identified six types of European livestock production areas characterised by contrasted bundles of services and impacts. Livestock management also appeared to be a key driver of bundles of services in prospective scenarios. These scenarios simulate a breakaway from current production, legislation (e.g. the use of food waste to fatten pigs) and consumption trends (e.g. halving animal protein consumption across Europe). Overall, strategies that combine a reduction of inputs, of the use of crops from arable land to feed livestock, of food waste and of meat consumption deliver a more sustainable food future. Livestock as part of this sustainable future requires further enhancement, quantification and communication of the services provided by livestock farming to society, which calls for the following: (i) a better targeting of public support, (ii) more precise quantification of bundles of services and (iii) better information to consumers and assessment of their willingness to pay for these services.

Improvements in feed efficiency of beef cattle have the potential to increase producer profitability and simultaneously lower the environmental footprint of beef production. Although there are many different approaches to measuring feed efficiency, residual feed intake (RFI) has increasingly become the measure of choice. Defined as the difference between an animal’s actual and predicted feed intake (based on weight and growth), RFI is conceptually independent of growth and body size. In addition, other measurable traits related to energy expenditure such as estimates of body composition can be included in the calculation of RFI to also force independence from these traits. Feed efficiency is a multifactorial and complex trait in beef cattle and inter-animal variation stems from the interaction of many biological processes influenced, in turn, by physiological status and management regimen. Thus, the purpose of this review was to summarise and interpret current published knowledge and provide insight into research areas worthy of further investigation. Indeed, where sufficient suitable reports exist, meta-analyses were conducted in order to mitigate ambiguity between studies in particular. We have identified a paucity of information on the contribution of key biological processes, including appetite regulation, post-ruminal nutrient absorption, and cellular energetics and metabolism to the efficiency of feed utilisation in cattle. In addition, insufficient information exists on the relationship between RFI status and productivity-related traits at pasture, a concept critical to the overall lifecycle of beef production systems. Overall, published data on the effect of RFI status on both terminal and maternal traits, coupled with the moderate repeatability and heritability of the trait, suggest that breeding for improved RFI, as part of a multi-trait selection index, is both possible and cumulative, with benefits evident throughout the production cycle. Although the advent of genomic selection, with associated improved prediction accuracy, will expedite the introgression of elite genetics for feed efficiency within beef cattle populations, there are challenges associated with this approach which may, in the long-term, be overcome by increased international collaborative effort but, in the short term, will not obviate the on-going requirement for accurate measurement of the primary phenotype.

To sustainably contribute to food security of a growing and richer world population, livestock production systems are challenged to increase production levels while reducing environmental impact, being economically viable, and socially responsible. Knowledge about the sustainability performance of current livestock production systems may help to formulate strategies for future systems. Our study provides a systematic overview of differences between conventional and organic livestock production systems on a broad range of sustainability aspects and animal species available in peer-reviewed literature. Systems were compared on economy, productivity, environmental impact, animal welfare and public health. The review was limited to dairy cattle, beef cattle, pigs, broilers and laying hens, and to Europe, North America and New Zealand. Results per indicators are presented as in the articles without performing additional calculations. Out of 4171 initial search hits, 179 articles were analysed. Studies varied widely in indicators, research design, sample size and location and context. Quite some studies used small samples. No study analysed all aspects of sustainability simultaneously. Conventional systems had lower labour requirements per unit product, lower income risk per animal, higher production per animal per time unit, higher reproduction numbers, lower feed conversion ratio, lower land use, generally lower acidification and eutrophication potential per unit product, equal or better udder health for cows and equal or lower microbiological contamination. Organic systems had higher income per animal or full time employee, lower impact on biodiversity, lower eutrophication and acidification potential per unit land, equal or lower likelihood of antibiotic resistance in bacteria and higher beneficial fatty acid levels in cow milk. For most sustainability aspects, sometimes conventional and sometimes organic systems performed better, except for productivity, which was consistently higher in conventional systems. For many aspects and animal species, more data are needed to conclude on a difference between organic and conventional livestock production systems.

Ruminants are unique among livestock due to their ability to efficiently convert plant cell wall carbohydrates into meat and milk. This ability is a result of the evolution of an essential symbiotic association with a complex microbial community in the rumen that includes vast numbers of bacteria, methanogenic archaea, anaerobic fungi and protozoa. These microbes produce a diverse array of enzymes that convert ingested feedstuffs into volatile fatty acids and microbial protein which are used by the animal for growth. Recent advances in high-throughput sequencing and bioinformatic analyses have helped to reveal how the composition of the rumen microbiome varies significantly during the development of the ruminant host, and with changes in diet. These sequencing efforts are also beginning to explain how shifts in the microbiome affect feed efficiency. In this review, we provide an overview of how meta-omics technologies have been applied to understanding the rumen microbiome, and the impact that diet has on the rumen microbial community.

Less than 2% of mammalian genomes code for proteins, but ‘the majority of its bases can be found in primary transcripts’ – a phenomenon termed the pervasive transcription, which was first reported in 2007. Even though most of the transcripts do not code for proteins, they play a variety of biological functions, with regulation of gene expression appearing as the most common one. Those transcripts are divided into two groups based on their length: small non-coding RNAs, which are maximally 200 bp long, and long non-coding RNAs (lncRNAs), which are longer than 200 nucleotides. The advances in next-generation sequencing methods provided a new possibility of investigating the full set of RNA molecules in the cell. In this review, we summarized the current state of knowledge on lncRNAs in three major livestock species – Sus scrofa, Bos taurus and Gallus gallus, based on the literature and the content of biological databases. In the NONCODE database, the largest number of identified lncRNA transcripts is available for pigs, but cattle have the largest number of lncRNA genes. Poultry is represented by less than a half of records. Genomic annotation of lncRNAs showed that the majority of them are assigned to introns (pig, poultry) or intergenic (cattle). The comparison with well-annotated human and mouse genomes indicates that such annotation is a result of lack of proper lncRNA annotation data. Since lncRNAs play an important role in genomic studies, their characterization in farm animals’ genomes is critical in bridging the gap between genotype and phenotype.

Piglet mortality has a negative impact on animal welfare and public acceptance. Moreover, the number of weaned piglets per sow mainly determines the profitability of piglet production. Increased litter sizes are associated with lower birth weights and piglet survival. Decreased survival rates and performance of piglets make the control of diseases and infections within pig production even more crucial. Consequently, selection for immunocompetence becomes an important key aspect within modern breeding programmes. However, the phenotypic recording of immune traits is difficult and expensive to realize within farm routines. Even though immune traits show genetic variability, only few examples exist on their respective suitability within a breeding programme and their relationships to economically important production traits. The analysis of immune traits for an evaluation of immunocompetence to gain a generally improved immune response is promising. Generally, in-depth knowledge of the genetic background of the immune system is needed to gain helpful insights about its possible incorporation into breeding programmes. Possible physiological drawbacks for enhanced immunocompetence must be considered with regards to the allocation theory and possible trade-offs between the immune system and performance. This review aims to discuss the relationships between the immunocompetence of the pig, piglet survival as well as the potential of these traits to be included into a breeding strategy for improved robustness.

The aim of this review is to focus the attention on the nutrition ecology of the heavy metals and on the major criticisms related to the heavy metals content in animal feeds, manure, soil and animal-origin products. Heavy metals are metallic elements that have a high density that have progressively accumulated in the food chain with negative effects for human health. Some metals are essential (Fe, I, Co, Zn, Cu, Mn, Mo, Se) to maintain various physiological functions and are usually added as nutritional additives in animal feed. Other metals (As, Cd, F, Pb, Hg) have no established biological functions and are considered as contaminants/undesirable substances. The European Union adopted several measures in order to control their presence in the environment, as a result of human activities such as: farming, industry or food processing and storage contamination. The control of the animal input could be an effective strategy to reduce human health risks related to the consumption of animal-origin products and the environmental pollution by manure. Different management of raw materials and feed, animal species as well as different legal limits can influence the spread of heavy metals. To set up effective strategies against heavy metals the complex interrelationships in rural processes, the widely variability of farming practices, the soil and climatic conditions must be considered. Innovative and sustainable approaches have discussed for the heavy metal nutrition ecology to control the environmental pollution from livestock-related activities.

In animals, new autosomal recessive genetic diseases (ARGD) arise all the time due to the regular, random mutations that occur during meiosis. In order to reduce the effect of any damaging new variant, it is necessary to find its cause. To evaluate the best way of doing this, 34 papers which found the exact location of a new genetic disease in livestock were reviewed and found to require at least two stages. In the initial stage the commonly used χ2 method, applied in a case-control association analysis with single nucleotide polymorphism (SNP)-chip data, was found to have limitations and was almost always used in conjunction with a second method to locate the target region on the genome containing the variant. The commonly used methods had their drawbacks; so a new method was devised based on long runs of homozygosity, a common feature of new ARGD. This ‘autozygosity by difference’ method was found to be as good as, or better than, all the reviewed methods tested based on its ability to unambiguously find the shortest known target region in an already analysed data set. Mean target region length was found to be 4.6 megabases in the published reports. Success did not depend on the size of commercial SNP-chip used, and studies with as few as three cases and four controls were large enough to find the target region. The final stage relied on either sequencing the candidate genes found in the target region or using whole genome sequencing (WGS) on a small number of cases. Sometimes this latter method was used in conjunction with WGS on a number of control animals or resources such as the 1000 bull genomes data. Calculations showed that, in cattle, less than 15 animals would be needed in order to locate the new variant when using WGS data. This could be any combination of cases plus parents or other unrelated animals in the breed. Using WGS data, it would be necessary to search the three billion bases of the cattle genome for base positions which were homozygous for the same allele in all cases and heterozygous for that allele in parents, or not containing that homozygote in unrelated controls. This site could be confirmed on other healthy animals using much cheaper methods, and then a genetic test could be devised for that variant in order to screen the whole population and to devise a breeding programme to eliminate the disorder from the population.

In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminants’ reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestors’ remains to be written. This perspective echoes archaeologists’ current attempts at reconstructing ancient pastoral societies’ socio-economical organization. Information related to birth seasonality may be retrieved directly from archaeological sheep teeth. The methodology consists of reconstructing the seasonal cycle record in sheep molars, through sequential analysis of the stable oxygen isotope composition (δ18O) of enamel. Because the timing of tooth development is fixed within a species, inter-individual variability in this parameter reflects birth seasonality. A review of the data obtained from 10 European archaeological sites dated from the 6th to the 3rd millennia BC is provided. The results demonstrate a restricted breeding season for sheep: births occurred over a period of 3 to 4 months, from late winter to early summer at latitudes 43°N to 48°N, while a later onset was observed at a higher latitude (59°N). All conclusions concurred with currently held expectations based on present day sheep physiology, which, aside from the historical significance, contributes to the reinforcing of the methodological basis of the approach. Further study in this area will permit regional variability attributable to technical choices, within global schemes, to be fully reported.

As the environments in which livestock are reared become more variable, animal robustness becomes an increasingly valuable attribute. Consequently, there is increasing focus on managing and breeding for it. However, robustness is a difficult phenotype to properly characterise because it is a complex trait composed of multiple components, including dynamic elements such as the rates of response to, and recovery from, environmental perturbations. In this review, the following definition of robustness is used: the ability, in the face of environmental constraints, to carry on doing the various things that the animal needs to do to favour its future ability to reproduce. The different elements of this definition are discussed to provide a clearer understanding of the components of robustness. The implications for quantifying robustness are that there is no single measure of robustness but rather that it is the combination of multiple and interacting component mechanisms whose relative value is context dependent. This context encompasses both the prevailing environment and the prevailing selection pressure. One key issue for measuring robustness is to be clear on the use to which the robustness measurements will employed. If the purpose is to identify biomarkers that may be useful for molecular phenotyping or genotyping, the measurements should focus on the physiological mechanisms underlying robustness. However, if the purpose of measuring robustness is to quantify the extent to which animals can adapt to limiting conditions then the measurements should focus on the life functions, the trade-offs between them and the animal’s capacity to increase resource acquisition. The time-related aspect of robustness also has important implications. Single time-point measurements are of limited value because they do not permit measurement of responses to (and recovery from) environmental perturbations. The exception being single measurements of the accumulated consequence of a good (or bad) adaptive capacity, such as productive longevity and lifetime efficiency. In contrast, repeated measurements over time have a high potential for quantification of the animal’s ability to cope with environmental challenges. Thus, we should be able to quantify differences in adaptive capacity from the data that are increasingly becoming available with the deployment of automated monitoring technology on farm. The challenge for future management and breeding will be how to combine various proxy measures to obtain reliable estimates of robustness components in large populations. A key aspect for achieving this is to define phenotypes from consideration of their biological properties and not just from available measures.

This paper reviews recent research into predicting the eating qualities of beef. A range of instrumental and grading approaches have been discussed, highlighting implications for the European beef industry. Studies incorporating a number of instrumental and spectroscopic techniques illustrate the potential for online systems to non-destructively measure muscle pH, colour, fat and moisture content of beef with R2 (coefficient of determination) values >0.90. Direct predictions of eating quality (tenderness, flavour, juiciness) and fatty acid content using these methods are also discussed though success is greatly variable. R2 values for instrumental measures of tenderness have been quoted as high as 0.85 though R2 values for sensory tenderness values can be as low as 0.01. Discriminant analysis models can improve prediction of variables such as pH and shear force, correctly classifying beef samples into categorical groups with >90% accuracy. Prediction of beef flavour continues to challenge researchers and the industry alike, with R2 values rarely quoted above 0.50, regardless of instrumental or statistical analysis used. Beef grading systems such as EUROP and United States Department of Agriculture systems provide carcase classification and some indication of yield. Other systems attempt to classify the whole carcase according to expected eating quality. These are being supplemented by schemes such as Meat Standards Australia (MSA), based on consumer satisfaction for individual cuts. In Australia, MSA has grown steadily since its inception generating a 10% premium for the beef industry in 2015-16 of $187 million. There is evidence that European consumers would respond to an eating quality guarantee provided it is simple and independently controlled. A European beef quality assurance system might encompass environmental and nutritional measures as well as eating quality and would need to be profitable, simple, effective and sufficiently flexible to allow companies to develop their own brands.

The Meat Standards Australia (MSA) grading scheme has the ability to predict beef eating quality for each ‘cut×cooking method combination’ from animal and carcass traits such as sex, age, breed, marbling, hot carcass weight and fatness, ageing time, etc. Following MSA testing protocols, a total of 22 different muscles, cooked by four different cooking methods and to three different degrees of doneness, were tasted by over 19 000 consumers from Northern Ireland, Poland, Ireland, France and Australia. Consumers scored the sensory characteristics (tenderness, flavor liking, juiciness and overall liking) and then allocated samples to one of four quality grades: unsatisfactory, good-every-day, better-than-every-day and premium. We observed that 26% of the beef was unsatisfactory. As previously reported, 68% of samples were allocated to the correct quality grades using the MSA grading scheme. Furthermore, only 7% of the beef unsatisfactory to consumers was misclassified as acceptable. Overall, we concluded that an MSA-like grading scheme could be used to predict beef eating quality and hence underpin commercial brands or labels in a number of European countries, and possibly the whole of Europe. In addition, such an eating quality guarantee system may allow the implementation of an MSA genetic index to improve eating quality through genetics as well as through management. Finally, such an eating quality guarantee system is likely to generate economic benefits to be shared along the beef supply chain from farmers to retailors, as consumers are willing to pay more for a better quality product.