Theses and Dissertations

Issuing Body

Mississippi State University


Kiess, Aaron S.

Committee Member

Wamsley, Kelley G. S.

Committee Member

Zhai, Wei

Date of Degree


Document Type

Graduate Thesis - Open Access


Poultry Science

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Poultry Science


Lactic acid producing bacteria (LAB) and organic acids have been proposed as effective alternatives to antibiotics, however there is limited literature concerning their combination. Thus, the objective of this thesis was to investigate the effects of LAB, encapsulated butyric acid (EBA), and their combination. Under challenged conditions, the in vitro study demonstrated that both EBA and LAB were capable of reducing pathogen proliferation over time, with greater efficacy at lower initial concentration. However, EBA demonstrated a greater effectiveness on pathogen reduction. Under challenged conditions, the results of the in vivo study indicated that birds fed LAB performed comparatively to that of birds fed antibiotics concerning BW and FCR from d 0-45 and both diets enhanced gut physiology, pH and immune parameters. Overall, the results of the thesis indicate the ineffectiveness of combining EBA and LAB, while providing valuable evidence supporting LAB as an effective alternative to antibiotics.