Animal Science, Department of


First Advisor

James C. MacDonald

Date of this Version

Spring 5-2020

Document Type



Wilson, H. C. 2020. Evaluation of Novel Additives and Corn Silage as Natural Alternatives to Antibiotics for the Prevention of Ruminal Acidosis and Liver Abscesses in Beef Finishing Cattle. PhD Dissertation. University of Nebraska, Lincoln.


A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Animal Science (Ruminant Nutrition), Under the Supervision of Professor James C. MacDonald. Lincoln, Nebraska: May, 2020

Copyright © 2020 Hannah C. Wilson


Receiving and finishing experiments were conducted to evaluate a non-antibiotic alternative for control of liver abscesses. There was no impact of Ramaekers Immune Primer (RAM; a proprietary blend of vitamins, minerals, prebiotics, and probiotics) treatment on overall performance. Compared to tylosin, RAM was not efficacious in reducing total liver abscesses.

A feedlot study was conducted comparing a natural feed additive (essential oils blend) at varying corn silage inclusion levels on receiving and finishing cattle performance. Inclusion of EO had no effect on performance. Feeding corn silage at greater inclusions decreased daily gain and feed efficiency but increased final body weight when cattle were fed to an equal fat endpoint. Essential oils did not affect animal performance, carcass characteristics, or economic return.

Two studies were conducted comparing different concentrations of corn silage (0, 7.5 and 15% of the diet DM and control treatment with 7.5% alfalfa) used as a roughage source on finishing performance, liver abscess prevalence, and ruminal fermentation characteristics. As expected, increasing available energy and decreasing roughage resulted in an increase in digestibility and VFA concentrations. However, there was a significant decrease in ruminal pH. Feeding cattle increasing amounts of silage as a roughage source had no effect on performance and carcass characteristics and can be utilized to minimize acidosis risk in feedlot cattle.

A finishing study was conducted to assess the impact of silage inclusion (15 and 45%, diet DM) in finishing diets to reduce the prevalence of liver abscesses in beef cattle. Feeding 45% silage was effective at lowering total liver abscess prevalence which were 12.4%, regardless of whether tylosin was fed. Feeding corn silage at 45% of diet DM was as effective as feeding tylosin to cattle on 85% concentrate diets due to increased hot carcass weights. Feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially at higher corn prices, provided silage shrink is well managed. Feeding elevated concentrations of corn silage may be an economically viable method to control liver abscesses without antibiotic use.

Advisor: James C. MacDonald