Rumen Systems Biology

The ruminant system converts fibrous feed of low nutritional value to a product of high nutritional value, via the actions of a symbiotic microbial population. Effectively it is a highly stable chemostat for microbial transformation of plant material into the volatile fatty acids and microbial cells that contribute directly to animal nutrition. The goal is to design forage substrates containing the correct balance of macro and micronutrients to promote effective fibre digestion and microbial proliferation whilst inhibiting methanogenic species. However, unlike the feed matching requirements of relatively simple industrial chemostatic systems, the requirements of the rumen in terms of species abundance and/or functionality to provide animal health and digestive efficiency is still incompletely understood, which to date has made it difficult to manipulate a priori. Furthermore, feed components can affect fermentation outputs but the mechanism underlying these effects is poorly described at the molecular level. In this sub-programme we will develop bioinformatic methodologies to enable examination of the whole rumen ecosystem in terms of the metagenomic, metatranscriptomic, proteomic and metabolomic datasets obtained from sub-programmes 2 and 3 and to inform in the construction of a systems/network model of the rumen. This resource will inform targeted rumen manipulation, either by development and use of appropriate feed additives or through selective plant breeding to incorporate key traits in forage to achieve improved production and/or quality targets.