Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Committee Chair(s)

Jennifer MacAdam


Jennifer MacAdam


Juan Villalba


Robert Ward


Freeman King


This study focused on how diet changes the rumen microbiome in the cattle and the effects of that on the long chain fatty acids (LCFA) by microbes in the rumen, and on the short chain fatty acids (SCFA) these microbes produce from feed carbohydrates like fiber and starch. The abundance of bacteria belonging to the phyla Tenericutes and Proteobacteria increased in response to high-fiber or high-starch diets, respectively. The production of two SCFA was positively correlated with the presence of increased Tenericutes (acetate) and Proteobacteria (propionate). A greater acetate to propionate ratio is associated with elevated production of enteric methane in the rumen, a lower ratio is more desirable. For LCFA, there are negative implications of omega-6 fatty acids and positive implications of omega-3 fatty acids for human health, so a lower omega-6 to omega-3 fatty acid ratio is considered more desirable.

Compared with grass-fed cattle, ecological concerns with raising beef can be mitigated in pasture systems by reducing methane emissions and improving soil health by using legumes that supply their own nitrogen. Compared with feedlot-finished cattle, the meat produced on birdsfoot trefoil pastures is healthier but better-tasting than the meat from grass-finished cattle. These benefits of non-bloating perennial legume pastures gives cattle producers an option for raising and marketing their own cattle that can increase beef profitability while reducing methane emissions and improving soil health.

A further result of this study was the communication of the results of a relatively complex scientific study through an extension video accessible to all interested farmers and ranchers, and a second video demonstrating the elements of making an accessible video for the Deaf and hard of hearing communities.