24TH ADSA DISCOVER CONFERENCE ON FOOD ANIMAL AGRICULTURE: NEW DEVELOPMENTS IN RUMEN MICROBIOLOGY AND THEIR POTENTIAL TO IMPROVE ANIMAL PERFORMANCE.
Report by Dr Christina Moon, AgResearch, New Zealand.
The focus of the 24th American Dairy Science Association (ADSA) Discover Conference was New Developments in Rumen Microbiology and Their Potential to Improve Animal Performance. Held in September 2012 at the Northern Illinois University Conference Centre in Naperville, USA, this friendly and informal meeting of around 150 participants fostered positive interactions between researchers and industry representatives from the disciplines of rumen microbiology to animal nutrition. The theme of the conference proved particularly timely as it coincided with the most extensive drought the US has seen in over 50 years, resulting in soaring feed costs, downsizing of herds and substantial financial losses to US farmers. Thus, advances in our understanding of the rumen microbiome, its composition, functions and interactions with the host; and how such new knowledge could be translated into new approaches and products to improve ruminant production were of significant interest.
The meeting programme was well-structured, starting off by providing updates in the advances and limitations of various aspects of rumen microbiology, including cultivation-based studies, culture-independent studies, and measuring the effects of microbial activities within the host. One of the of the most significant advances in recent years has been the impact of next generation sequencing (NGS) technologies on rumen microbiology, which has enabled highly extensive and cost effective monitoring of microbial communities and community shifts in response to environmental changes, as well as greater interpretation of the functions of the rumen microbiome through genomic, metagenomic and transcriptomic analyses. The importance of integrating NGS-based community profile analyses within animal trials were highlighted to obtain a more holistic view of the host/microbiome/environment complex, and identify microbiological community shifts that correlate with, or potentially underpin, observed changes between treatment groups. Such analyses were well received by the animal scientists, and there was interest on how best to collect appropriate samples for these analyses. On the flipside, some methodologies and standards for measuring various microbial activities both in vivo and in vitro had not advanced for some 30-40 years and there was great interest in developing more accurate and precise tools.
The participants were treated to excellent presentations highlighting developments on the understanding of the biology of some of the major rumen microbial taxa - the bacteria, protozoa and fungi, which the application of NGS has had a substantial impact. However, with the accumulation of sequence data, the need for follow-up functional analyses was also emphasized, where it was demonstrated that extrapolating function from sequence homology to database information can be misleading. There was a very interesting consideration of the roles of protozoa within production systems, and ‘omics technologies have played a large part in revealing the extent of the innovative strategies employed for fibre degradation by the fastidious microbial "good guys", the rumen fungi.
These presentations set the foundations for updating developments on ruminal processes such as fibre degradation, nitrogen utilization and methanogenesis; how the host and microbiome communicate; and probably, the area of greatest interest and discussion within the meeting: prospects for manipulating the rumen microbiome. Despite the recent and substantial advances in the knowledge bank of the biology of rumen microbes, manipulating the rumen microbiome remains a highly challenging area, where efforts to inoculate the rumen with organisms of interest, or alter the rumen microbial community composition using biotic or abiotic means have met with mixed results. Also the ability of the rumen community to stabilise after perturbation appeared to take much longer than had been previously recognised, which may also have impact on the design of animal trials. However, a promising area of manipulation appears to be in the young ruminant, where the application of treatments early after weaning has shown promise for imprinting the microbiome at adulthood. On a practical level, the economic reality of commercial products was highlighted, where the view that in these tough economic times, farmers aren't really interested in new products unless they cost less than a dime per cow per day. This certainly provides further challenge for products to be produced cost-effectively, or have major effects on production. Concern was also expressed for the low numbers of graduates in animal sciences and rumen microbiology in recent years and how this will impact industry progress in the future.
Overall though, this was a really enjoyable and informative meeting, not only for the excellent calibre of the presentations made by the speakers, but also for the contributions of the participants via the extensive discussion sessions that were held. The small format of the meeting enabled quality engagement between participants, which contributed successfully to one of the key aims of the conference - to provide a foundation for the development of new technologies and products based upon research advances in rumen microbiology and nutrition to improve ruminant production. More information on the 24th ADSA Discover Conference, including the programme and the speakers, can be found at http://adsa.org/Meetings/DiscoverConferences/24thDiscoverConference.aspx.
Photo caption: Prof. Jamie Newbold discusses successes and failures of directed manipulation of the rumen microbiome.
