Date of Award


Degree Type


Degree Name

Master of Science - Agriculture



First Advisor

Dr. Joey Bray

Second Advisor

Dr. Dale Perritt

Third Advisor

Dr. John Michael Mehaffey

Fourth Advisor

Dr. Karen Embry-Jenlink


The objective of this study was to evaluate Bacillus megaterium, Bacillus licheniformis, and Bacillus subtilis, as probiotic strains compared to Bacitracin Methylene Disalicylate (BMD) 50 as the antibiotic growth promotor, supplemented in commercial broiler rations and their influences on performance, yield, and intestinal microbiota. This trial was completed as a randomized-block design with 4,800 birds split into 96, 5’x10’ pens, and randomly assigned to one of eight treatment groups. The birds were placed at a stocking density of 1.00 ft2/bird, (50 birds/pen), and reared on used pine shaving for 55 days. Throughout the study, bird performance, and intestine samples were measured. A yield study was completed at the end of the study to determine meat yield for all retail cuts. Results show treatment 3, (LS + AGP), which consisted of the following probiotics and antibiotic growth promotors: Bacillus licheniformus, Bacillus subtilis, and BMD with Maxiban in the starter and grower diets as the coccidiostat, performed better overall compared to the negative and positive control treatments.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.



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