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We aimed to establish common guidelines for experimental studies with cattle.A book on “Methods in cattle physiology and behaviour research” was published.The book is designed as an open-access living handbook and is open to everyone.Citing the book saves space and avoids repetitions in scientific journals.Referencing guidelines reduces apparent plagiarism among authors.

International audience; The future sustainability of cattle production will require improved resource use efficiency, reduced GHG emissions, and improved animal health and welfare. Facing this challenge needs far more complex animal traits than previously and they need to be assessed under a range of conditions. For example, the concepts of feed efficiency, robustness and sensitivity to health disorders are more difficult to include in selection indices than simple productivity traits. It is now time to look for means to investigate complex animal traits using smart technologies and rapid analytical methods in a standardised way applied in many contexts. At the same time, the European Strategy Forum on Research Infrastructures (ESFRI) roadmap clearly identified the need for improved coordination, harmonisation and access to European research infrastructures (RIs) on farm animals. The SmartCow project (www.smartcow.eu) answering the call H2020-INFRAIA2016-2017 was selected by the European Commission for 4 years funding starting from 1st February 2018. Three types of activities are developed to increase the phenotyping capabilities of the cattle European sector. Networking activities will create, thanks to an inventory and an interactive map, a unique portal to key European cattle RIs. The project will ensure that existing guidelines are adopted [e.g., the ICAR Guidelines for Bovine Functional Traits (section 7) are cited in distinct guidelines generated by the Networking activities]. When no international standard exists (e.g. feed efficiency, digestive, behavioural traits…), the project works towards the use of unified measurement methods through common standards and guidelines. The development of the cattle ontology of traits (ATOL and EOL; www.atol-ontology.com) through SmartCow will also be an important step to unify research methodologies and link definition of traits with standardized methods. A cloud-based database platform developed by Agrimetrics using web semantic will ensure integration, sharing and interoperability of data generated by the project leading to an open European database on cattle traits and phenotypes. Joint research activities will generate innovations for the research community on cattle towards the use of less-invasive methods and high-throughput phenotyping. Refining in vivo methods to evaluate feed efficiency and emissions will generate innovations in experimental design and planning for more accuracy. The development of new biomarkers (proxies) that can be easily measured in milk, faeces, urine, or blood through rapid analytical methods (NIRS) will bring new phenotyping capacities. The development of tools to generate new and improved information from animal sensors and other routinely collected data (e.g. prediction of individual cow status in terms of health and welfare) will also enable a more efficient phenotyping and genetic selection of cattle. Finally, the project organizes transnational access to major RIs: INRA in France, Scotland’s Rural College and University of Reading in the UK, Wageningen University and WUR/DLO in the Netherlands, FBN-Leibniz in Germany, Teagasc in Ireland, Aarhus University in Denmark and IRTA in Spain. It provides access to around 2500 dairy and 1000 beef cattle and facilitate up to 30 research projects to be financed by the SmartCow project after selection through specific calls. Eleven projects have already been selected after the first call.

The distinctive membrane lipids of the archaea can contain a wide range of chemical structures. The membrane lipid composition of ruminal methanogenic archaea has not yet been characterized. In this study, we analyzed proportions of the core archaeal membrane lipids dialkyl glycerol diethers (DGDG) and glycerol dialkyl glycerol tetraether (GDGT). We analyzed the feces of beef steers consuming diets that promoted differences in ruminal conditions that were either favorable (i.e., grass silage) or challenging (i.e., concentrates) for the methanogenic archaea. There was significantly less total ether lipid in the feces of cattle consuming the concentrate diet in comparison to the grass silage diet (97 vs. 218 mg/kg DM, respectively), reflecting the inhibitory effect of dietary concentrate on methanogens. Additionally, the proportion of fecal ether lipids as GDGT was much greater in feces from cattle consuming the concentrate diet than in feces from cattle fed grass silage (90% vs. 67% GDGT). A possible explanation for this adaptation is that membrane lipids composited of GDGT lipids are less permeable to protons, thereby protecting the methanogens against low ruminal pH and helping to maintain the chemiosmotic potential (which is important for ATP production, methanogenesis, and growth). The greater proportion of fecal ether lipids as GDGT may reflect adaptation of membrane lipids within the same species, a shift toward methanogens that have a greater proportion of GDGT (e.g., Thermoplasmata), or both. The effect of ruminal environment on membrane composition means that it will be important to consider the production of both DGDG and GDGT lipids when developing a proxy for methanogenesis.

International audience; Legume forages have an important position in ruminant production in Western Europe and with further development can play an even larger role. Red clover for silage and white clover in grazed swards lead to enhanced growth rate and milk yield in comparison with pure grasses. Much of the production benefit of these legumes relates to enhanced intake since digestibilities are not markedly different to grasses. The higher intake of legume silages reflects differences in the cell structure of legume plants which combined with high fermentation rates means that they break down into small particles in the rumen, and leave the rumen more rapidly than perennial ryegrass. Ease of ingestion leads to high rates of intake, which explains higher intakes for grazed legumes. A further benefit of legumes is the reduced rate of decline in digestibility with advancing maturity. Whilst legumes have limited effects on gross milk composition or carcass characteristics, there are marked increases in levels of beneficial n-3 PUFA. Legumes have often led to a reduction in methane production from the rumen and again, this relates to both physical and chemical differences between forage species. The high rates of release of soluble protein and of breakdown to small particles from clovers and lucerne is associated with susceptibility to bloat, which is a limitation to further exploitation in grazing systems. The high concentration of rapidly degraded protein in legumes also leads to inefficient utilisation of dietary N and increased urinary N output. Research with tanniniferous forages, such as birdsfoot trefoil and sulla, demonstrates the potential for future legumes with reduced environmental and health effects, though these particular forage legumes are not well adapted to temperate regions of Western Europe that are the focus of this review.

The experiment investigated the digestion of lipids from different forage silages in beef steers. Six Hereford x Friesian steers prepared with rumen and duodenal cannulas were given ad libitum access to a high-sugar grass silage, control grass silage, red clover silage, or mixtures of the red clover and each of the grass silages (50:50, DM basis). The experiment was conducted as an incomplete 5 x 5 Latin square, with an additional randomly repeated sequence. Total fatty acid and C18:3n-3 concentrations were greater (P

Two experiments were carried out to determine the effects of feeding grass silages differing in their water-soluble carbohydrate content, with or without red clover silage, on the efficiency of nutrient use. High-sugar grass, control grass, and red clover were ensiled in laboratory silos for use in an in vitro experiment (Exp. 1). For an in vivo experiment (Exp. 2), the same forage types were baled and ensiled. All silages were well preserved; within experiments the grass silages had similar composition, except for greater (P < 0.05) water-soluble carbohydrate concentrations in the high-sugar than the control grass silage. In Exp. 1, high-sugar grass, control grass, and red clover silages were fed alone or as mixtures (30:70, 50:50, or 70:30 on a DM basis, respectively) of each grass with the red clover silage to a simulated rumen culture system. There were no significant differences in microbial N flow or efficiency of microbial protein synthesis between individual forages. However, the corresponding values for the 70:30 ratio of high-sugar grass:red clover silage were greater (P < 0.05) than for the red clover silage. The value for the efficiency of N use (g of microbial N/g of feed N) was greater (0.86; P < 0.05) for high-sugar grass silage than the control grass silage. In addition, the high-sugar grass:red clover silage mixtures all gave greater (P < 0.05) values for the efficiency of N use than red clover silage alone; this difference was not achieved with the control grass mixture. Experiment 2 was an incomplete Latin square design conducted with 6 Here-ford × Friesian steers (163 ± 5.9 kg of BW) with rumen and duodenal cannulas fed the following 5 silage diets: high-sugar grass silage; control grass silage; high-sugar grass and red clover silage (50:50 DM basis); control grass and red clover silage (50:50 DM basis); and red clover silage. Rumen NH3-N concentration was lowest (P < 0.05) with the high-sugar grass silage. Microbial N flows to the duodenum and efficiency of microbial protein synthesis were greater (P < 0.05) for steers fed the high-sugar grass silage than for control grass and red clover silages, and mixing red clover with grass silages increased (P < 0.05) these values compared with red clover silage alone. In both experiments, the efficiency of incorporation of silage N into microbial N was more than 20% greater (P < 0.05) for high-sugar grass than for control grass silage. These data suggest that grass silage with high-sugar content provides a forage-based strategy for balancing N and ene