Improved cattle feed efficiency via bacteriophage-mediated microbiome manipulation

Cattle production is the most economically important US agricultural activity but the industry isunder pressure to improve sustainability as beef production uses more land and energy than othermajor protein sources. Improving feed efficiency is arguably the best approach for enhancingsustainability as much of the cost and environmental footprint of cattle production is due to feedproduction. Though numerous factors influence cattle feed efficiency many recent studies havedemonstrated that rumen microbiome composition plays a key role. Phages are promising tools foraltering microbiomes and we recently developed phage libraries active against Streptococcus andFusobacterium - rumen genera that have substantial influence on feed efficiency. Accordingly thegoal of this project is to develop a phage-based feed additive that increases cattle feed efficiencyand is compatible with current feed manufacturing and cattle production processes.To achieve broad coverage of bacterial strains found in contemporary production settingsStreptococcus phages will be subjected to in vitro host range expansion protocols. Fusobacteriumphages will be subjected to in vitro protocols designed to enhance their killing efficiencies againstresistant bacteria. Phage thermal stability and their potential for thermal adaptation will then beassessed.Subsequently promising candidates will undergo yield optimization and production scaleup. Finally efficacy and optimal treatment strategies will be determined using in vitro studies andanimal trials. Successful completion of this project would be economically beneficial for producersand would help mitigate the environmental impacts of animal agriculture while establishing ageneralizable cost-effective framework for livestock microbiome engineering.