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Des scientifiques et des représentants de la filière « viande bovine » en Europe se sont réunis les 1er et 2 octobre à Milan à l’occasion d’un congrès intitulé « Qualité durable de la viande bovine en Europe – un congrès pour les professionnels et les scientifiques ». Le but de ce congrès était de faciliter les échanges et de consolider les liens entre les acteurs de la filière viande bovine et les chercheurs en viande. De courtes présentations ont eu lieu sur 15 sujets relatifs à la qualité, la compétitivité et la durabilité de la production de viande bovine en Europe. Ces présentations ont traité de la qualité gustative en bouche de la viande bovine produite en Europe, et des applications pratiques par les acteurs de la filière des résultats scientifiques afin d’améliorer la qualité et la durabilité de la production de la viande bovine en Europe. Les présentations ont également porté sur les outils disponibles ou en préparation pour aider à la production de viande bovine de bonne qualité. Les congressistes ont participé à deux réunions de travail pour réfléchir aux questions suivantes : « Comment l’Europe peut-elle valoriser au mieux sa production de viande bovine ? » et « Que faut-il faire pour assurer la durabilité de la production de viande bovine en Europe durant les 10 prochaines années ? ». Cet article présente un résumé des présentations et des réflexions issues des deux réunions de travail., Beef industry representatives and scientists from across Europe met on 1-2 October 2015 in Milan for a workshop entitled "Sustainable beef quality for Europe – a Workshop for Industry and Scientists". The aim of the workshop was to facilitate knowledge exchange and strengthen links between scientists and industry across Europe. Short presentations were given on 15 topics of relevance to the quality, competitiveness and sustainability of European beef. These covered the eating quality of European beef, the practical application of science by the beef industry to improve quality, sustainability of European beef production and the tools available or in preparation to assist the industry in the delivery of quality beef. Participants also contributed to two workshops which asked "How can Europe get the best value from its beef?" and "What is needed to ensure sustainability of the European beef industry for the next 10 years?". This article presents a summary of these articles and the outcomes of the workshops.

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International audience; The study investigated in vitro simulated rumen metabolism of freshly cut and wilted cocksfoot [Dactylis glomerata; high polyphenol oxidase (PPO)] and tall fescue (Festuca arundinacea; low PPO). A 16-vessel RUSITEC was used with the four treatment combinations: cocksfoot wilted (C(w)); cocksfoot fresh (C(f)); tall fescue wilted (TF(w)) and tall fescue fresh (TF(f)). Rumen liquor was collected from four fistulated dairy cows maintained on permanent pasture. The experiment ran for 12 d with sampling of effluent for rumen parameters [volatile fatty acids (VFA) and NH(3)-N] on days 10 and 11 at 0, 1, 2, 3, 4, 6, 8 and 24 h intervals. On days 9-12, gas production and composition were measured using a plastic gas collection bag attached to the effluent bottle. At the end of day 12, the grass residue and effluent from the vessels were collected and analysed for digestibility and lipid fractionation. Lipolysis was calculated as the proportional loss of glycerol-based membrane lipid between the forage and residue. Polyphenol oxidase was higher (P < 0 center dot 001) in C(f) than the other treatments; C(w) was higher than both TF treatments, with no difference between TF(w) and TF(f). The level of protein-bound phenol (product of oxidation reaction) tended to be higher for C(w) and TF(w) than C(f) and TF(f), (P < 0 center dot 1) and was higher for cocksfoot than tall fescue (P < 0 center dot 001). As an average across the day, NH(3)-N was lower (P < 0 center dot 001) in cocksfoot than tall fescue, despite the lower nitrogen concentration of tall fescue, and in fresh as opposed to wilted grass (P < 0 center dot 001). There was a trend (P < 0 center dot 1) for lipolysis to be lower in cocksfoot than tall fescue, and for both wilted treatments to be lower than the fresh (P < 0 center dot 05). Total VFA concentration was not different across treatments, although there were differences in molar proportions of individual VFA. Cocksfoot as opposed to tall fescue showed a small effect in lowering lipolytic and proteolytic activity (release of NH(3)-N), although other differences between the grasses other than just PPO activity such as lipase activity, diphenol substrate content and digestibility may have greater effects between the grasses confounding the effect of PPO.

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BACKGROUND: The enzyme polyphenol oxidase (PPO) reduces the extent of proteolysis and lipolysis within red clover fed to ruminants with subsequent increases in the efficiency of N utilization and the level of beneficial polyunsaturated fatty acids in their products (meat and milk). It has also been reported that red clover feeding alters the rumen microbial population compared to grass feeding. This study investigated whether the observed shifts in the microbial population of the rumen when ruminants are fed red clover silage (RC) as opposed to grass silage (G) represented an adaptation by the micro-organisms to increase the utilization of PPO-protected protein and glycerol-based lipid. RESULTS: The experiment consisted of two periods where ruminally fistulated dairy cows were offered either RC or G for 2 weeks, followed by collection of rumen fluid, which was then used in in vitro incubations to investigate lipolysis and proteolysis over time in plant material derived from red clover plants with either wild type PPO expression (PPO+) or PPO expression reduced to undetectable levels by gene silencing (PPO-). Proteolysis and lipolysis (P

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