Evaluation of L28 direct-fed microbial or sub-therapeutic antibiotics with or without an ionophore on rumen parameters in a continuous culture model

Abstract

This study seeks to further elucidate the effects of a newly isolated strain of Lactobacillus salivarius L28 in comparison to Tylosin, a commonly fed sub-therapeutic antibiotic. Therefore, the objective of this project is to evaluate the effects of a newly developed TTU direct-fed microbial (Lactobacillus salivarius L28) and tylosin, with and without sodium monensin, on rumen parameters in a continuous culture model. The experiment will be conducted in the Texas Tech Burnett Center, and the rumen fluid samples will be collected from previously ruminally-cannulated cattle. The samples will be incubated in a continuous culture system, where the following treatments will be evaluated: CON (No tylosin, L28, or sodium monensin), TY (Tylosin), MONTY (sodium monensin and Tylosin), PRO (L28), MONPRO (Monensin sodium and L28). After culture, the following variables will be measured and assessed: short-chain fatty acid (SCFA) concentrations, pH, ammonia nitrogen (NH3-N), microbial protein efficiency, and organic matter digestibility. At the end of the experiment, all data will be analyzed with the in vitro incubation chamber as the experiment unit (n = 6 per treatment), treatment as the fixed effect (n = 5), and batch (n = 3) as a random effect in the GLIMMIX procedures of SAS. (AU)