The symbiotic rumen microbiome and cattle performance: a brief review

Abstract

The rumen of the dairy cow contains a rich and diverse collection of microbes that during feed digestion produce significant quantities of methane gas and ammonia, both of which contribute to greenhouse gas emissions. Strategies to redirect rumen carbon and nitrogen metabolism away from these products provide opportunities for significant productivity improvements in livestock systems not only by improving nutrient retention, but also by reducing greenhouse gas emissions. In order to develop these strategies, a greater knowledge of the diversity of the microbes within their rumen and their genomic capability is required. Many have used several techniques to study the rumen microbes, and the technology continues to improve. Among them include researchers at the Department of Primary Industries Victoria (DPI Vic) and the Dairy Futures Cooperative Research Centre (CRC) who are addressing the issue of regulation of methane emissions in dairy cattle, while scientists in Queensland and New South Wales, as part of the most recent Beef CRC program, focus on beef cattle. In this brief review, we examine how the techniques used in rumen microbial ecology have changed, and how technology improvements continue to allow us to examine the rumen microbiota of cattle and other ruminants, so as to better understand and possibly select animals with superior traits, leading to improvements in feed efficiency, methane emissions and nitrogen retention.

In vitro ruminal fermentation of treated alfalfa silage using ruminal inocula from high and low feed-efficient lactating cows

“…It has also been found that feeding formic acid-treated silage to lactating cows increased plasma concentration of amino acids and milk yield (Nagel and Broderick 1992). Greater feed conversion efficiency had be related to less methane per unit of dry matter intake and potentially less nutrients excreted to the environment (de Haas et al 2011;Waghorn and Hegarty 2011;Hernandez-Sanabria et al 2012;Bath et al 2013;Arndt et al 2015).…”

“…and Eubacterium rectale were associated with low RFI steers while Robinsoniella peoriensis was associated with high-RFI steers. In a different study, Bath et al (2013) reported that 33% of the variation in RFI data in dairy cattle was associated with the following ruminal species: Selenomonas ruminantium, Fibrobacter succinogenes, and Prevotella spp. The S. ruminantium numbers may account for 24% of this variation.…”

Unravelling methanogenesis in ruminants, horses and kangaroos: the links between gut anatomy, microbial biofilms and host immunity

“…Molecular analysis based on bacterial 16S rRNA sequences has revealed that more than 1000 different species of bacteria are represented in the human gut microbiome (Eckburg et al 2005) and most of these species have not been able to be cultured in vitro. Dominant bacteria are being identified in humans by using these new tools that are now also being applied to the rumen (Bath et al 2013;de Mulder et al 2016) and the macropod forestomach (Godwin et al 2014). Recent molecular analyses of the composition of rumen ecosystems have demonstrated that there is great complexity within the myriad of species present in biofilms in any one location (de Mulder et al 2016).…”

Evaluation of 16S rRNA amplicon sequencing using two next-generation sequencing technologies for phylogenetic analysis of the rumen bacterial community in steers

“…The microbial ecosystem of the cattle rumen has been extensively studied (Bath et al, 2013;Myer et al, 2015a;Pitta et al, 2010), and has a complex and diverse structure that is essential for the host to digest plant material. Recent research has focused on characterization of the rumen microbiome among animals differing in feed efficiency (Jami et al, 2014;McCann et al, 2014).…”