Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.

Perennial ryegrass (Lolium perenne L.) infected with a novel endophyte (AR37 or AR1), Wild‐type endophyte or no endophyte (Nil) was sown with white clover (Trifolium repens L.) in autumn 2005. The pastures were rotationally grazed by dairy cows from 2005–2009. Annual dry matter (DM) yield did not differ but AR37 pastures had a higher ryegrass tiller density, especially after the 2008 summer drought (+130%), and less white clover than did AR1 pastures. Concentrations of alkaloids produced by the Wild‐type association (lolitrem B, ergovaline) followed the same seasonal trends as did the AR37 alkaloids (epoxy‐janthitrems) but summer drought reduced concentrations of lolitrem B and epoxy‐janthitrems to less than half the mid‐summer (February) peak concentrations in the other years. Insect pests were monitored annually between 2006 and 2009. Tiller damage by Argentine stem weevil (Listronotus bonariensis (Kuschel)) was significantly reduced by all endophyte treatments. African black beetle (Heteronychus arator (F.)) populations in soil samples increased during the experiment with Nil > AR1 > Wild‐type = AR37. Root aphid (Aploneura lentisci (Pass.)) infestations followed the pattern AR1 > Nil > Wild‐type = AR37. A lower pest pressure from all insect pests in AR37 pastures is likely to have contributed to this treatment having the highest ryegrass tiller densities.

Chicory (Cichorium intybus L.) and narrow-leaved plantain (Plantago lanceolata L.) are able to grow a large amount of high-quality summer feed. Limited information is available on the effect of grazing management on plantain, and no comparison been undertaken of modern chicory and plantain cultivars used in dairy production systems. This study determined the effect of defoliation interval (as determined by the extended leaf height, ELH) and residual height on the yield, nutritive characteristics and plant density of chicory and plantain over 18 months. Chicory leaf yield was reduced in swards defoliated at 150 mm ELH compared with those defoliated at 250, 350 or 550 mm (14.3 v. 17.5 t DM ha–1), and chicory stem yield was least in swards defoliated at 150 or 250 mm. Plantain swards defoliated at 350 or 450 mm ELH yielded more leaf than those defoliated at 150 or 250 mm (20.4 v. 16.7 t DM ha–1); however, stem yield also increased with increasing defoliation interval. Over all seasons, as defoliation interval increased, generally, neutral detergent fibre content increased and crude protein, ash and digestibility declined. Residual height had less of an effect on yield and nutritive characteristics than did defoliation interval. To maximise chicory leaf growth while minimising growth of lower quality stem, the optimal ELH over 18 months was 250 mm, or if the chicory was used only as a 9-month ‘summer’ crop, 350 mm. Recommendations for plantain are not as simple because longer defoliation intervals increase both leaf and stem yield and reduce nutritive value. Defoliating plantain swards at 250 mm ELH appeared to provide a balance between yield and nutritive value; however, further work is required to determine the impact of applying these recommendations on a dairy farm system.

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