There is a great demand for high-protein materials for livestock feed in Europe and European agriculture has a deficit of about 70% high protein materials of which 87% is met by imported soybean and soy meal. This reflects the fact that grain legumes are currently under represented in European agriculture and produced on only 1.5 % of the arable land in Europe compared with 14.5% on a worldwide basis. Several grain legumes have the potential to replace at least some of the soya currently used in the diets of monogastric animals, ruminants and fish. There are also opportunities for greater use of legumes in new foods. Here we review the contribution of ecosystem services by grain legumes in European agriculture starting with provisioning services in terms of food and feed and moving on to the contribution they make to both regulating and supporting services which are in part due to the diversity which these crops bring to cropping systems. We explore the need to understand grain legume production on the time scale of a rotation rather than a cropping season in order to value and manage the agronomic challenges of weed, pests and diseases alongside the maintenance or improvement of soil structure, soil organic matter and nutrient cycling. A review of policy interventions to support grain legumes reveals that until very recently these have failed to make a difference in Europe. We contrast the European picture with the interventions that have allowed the development of grain legume production in both Canada and Australia. Whether farmers choose to grow more legumes will depend on market opportunities, the development of supply chains and policy support as well as technical improvements of grain legume production such as breeding of new varieties and management development to improve yield stability. However, to really increase the production of grain legumes in Europe the issues are far more wide reaching than agronomy or subsidy and require a fundamental rethinking of value chains to move grain legumes from being niche products to mainstream commodities.

Four lactating cows fitted with ruminal cannulae and fed a grass silage-based diet were used in a 4 × 4 Latin square with 28-d periods to investigate the effects of incremental dietary fish oil (FO) supplementation (0, 75, 150, or 300 g/d) on the flow of fatty acids at the omasum and populations of rumen bacteria capable of biohydrogenation. FO decreased silage intake and ruminal volatile fatty acid concentrations and promoted an increase in molar butyrate and propionate proportions at the expense of acetate. Extensive ruminal biohydrogenation of 20:5(n-3) and 22:6(n-3) resulted in corresponding increases in numerous 20- and 22-carbon unsaturated fatty acids at the omasum. Omasal flow of several 20-, 21-, and 22-carbon all-cis (n-3) PUFA exceeded the intake from FO. Supplements of FO also induced a dose-dependent decrease in 18:0 and increased trans 18:1 and trans 18:2 flow at the omasum. Trans-11 was the major 18:1 intermediate in digesta, while FO induced quadratic increases in trans-10 18:1 flow, reaching a maximum of 300 g/d. FO had no substantial influence on omasal flow of CLA. Results suggest that one or more fatty acids in FO inhibit the reduction of trans-18:1 and trans-18:2 intermediates by ruminal microorganisms. qPCR based on 16S rRNA genes in omasal digesta indicated that key Butyrivibrio spp. declined linearly in response to FO. Dose-dependent increases in ruminal outflow of biohydrogenation intermediates containing one or more trans double bonds in response to FO has major implications for host metabolism and the nutritional quality of ruminant foods.

The response of dairy cows fed grass silage-based diets to the abomasal infusion of water (control) or 6.5 g of His alone or in combination with either 6.0 g of Met or 19.0 g of Lys or both was studied in an incomplete 4 x 5 Latin square experiment with 14-d periods. Each cow received a basal diet of 8 kg/d of cereal concentrate [12.1% crude protein (CP)] and free access to grass silage (14.1% CP) ensiled with an acid-based additive. Postruminal infusions increased arterial plasma concentrations of the amino acids (AA) infused, but compared with control, only the infusion of His (18 vs. 57 mumol/L) was associated with significant increases in milk and milk protein yields. Infusions of His did not affect dry matter intake of grass silage, rumen fermentation, or diet digestibility. Milk protein content was unchanged by treatments, but His infusions decreased lactose and fat contents. The combinations of AA did not produce any further responses compared with His alone. However, milk protein percentage was slightly higher, and milk fat percentage tended to be higher when Met rather than Lys was infused with His. We concluded that His is the first-limiting AA when grass silage-based diets are supplemented with cereal concentrates, while neither Met nor Lys are the second-limiting AA with grass silage feeding.

Four ruminally and duodenally cannulated multiparous Finnish Ayrshire cows were fed on diets consisting of grass silage (0·6 kg/kg DM) and one of four concentrates: barley, barley + urea, barley + rapeseed meal and barley + rapeseed cake. The objective of the present study was to compare omasal canal and duodenal digesta flows. Values for digesta flow into the omasal canal and duodenum were determined using a triple-marker method based on Co-EDTA, Yb-acetate and indigestible neutral-detergent fibre (NDF) markers. Microbial non-NH3 N (NAN) flow was assessed by purine flow. Microbial samples to determine the bacterial purine: N ratio were harvested from the rumen, omasum and duodenum. Organic matter flow was significantly lower into the omasum than the duodenum, indicating an endogenous organic matter secretion into the abomasum. In contrast, NDF and acid-detergent fibre flows were significantly higher into the omasum indicating digestion of fibre in the omasum. Microbial NAN flows were significantly different (P < 0·001) when estimates were based on bacterial samples harvested from different sites. Differences in total NAN, microbial NAN and dietary NAN flows entering the omasal canal and duodenum were non-significant. The results indicated that the omasal sampling technique provides a promising alternative to the duodenal sampling technique to investigate forestomach digestion in dairy cows and offers an alternative means to study rumen N metabolism.