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 and has ahigher global warming potential than other major protein sources. Improving feed efficiency isarguably the best approach for enhancing sustainability as much of the cost and environmentalfootprint of cattle production is due to feed production. Though numerous factors influence cattlefeed efficiency many recent studies have demonstrated that rumen microbiome composition playsa key role. Bacteriophages are promising tools for altering microbiomes but their stringent host- specificity has hindered their widespread adoption.Yet contrary to the common belief thatbacteriophages are highly specific we recently developed methods to isolate wide host-range(polyvalent) bacteriophages and have found them to be highly effective for microbial control.Advantages of polyvalent over narrow host-range bacteriophages include decreased phage cocktailcomplexity higher titers in environments with multiple hosts (e.g. rumen) decreased phage decayrates enhanced biofilm propagation and more economical production.The goal of this project is to develop polyvalent bacteriophage libraries for rumen microorganismsassociated with cattle feed efficiency including Methanobrevibacter ruminantium Anaerovibriolipolyticus Fusobacterium sp. and Streptococcus bovis. Bacteriophages will be isolated usingspecialized methods that select for those with a predetermined host-range based on rumenmicrobiome composition. Each bacteriophage will then be characterized and tested for efficacywithin a bioreactor operated to simulate the cattle rumen. Bacteriophage cocktails will beformulated and tested for their ability to minimize the development of bacteriophage resistance.