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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Biosciences & Biotechnology Laboratory » Research » Research Project #433349

Research Project: Alternatives to Antibiotics: Developing Novel Strategies to Improve Animal Welfare and Production Efficiency in Swine and Dairy

Location: Animal Biosciences & Biotechnology Laboratory

Project Number: 8042-31440-001-00-D
Project Type: In-House Appropriated

Start Date: Jul 24, 2017
End Date: Jul 23, 2022

Objective:
Objective 1) Develop alternative strategies to replace or reduce the use of conventional antibiotics for improved growth, animal health and product safety. A. Develop alternative antimicrobials to treat or prevent diseases in swine and dairy. B. Develop transgene-expressing cell transplantation methods to enhance growth rate and to treat or prevent diseases in swine. C. Develop effective dietary/nutritional regimens that can be implemented to maintain the healthful character of the gut of weanling swine. Objective 2) In order to develop alternatives to antibiotic growth promoters, identify mechanisms underlying the growth promoting effects of antibiotics in swine. A. Establish which microbial population distribution patterns are predictive of GI health and efficient nutrient utilization. B. Identify biomarkers of gut health and efficient nutrient utilization that are associated with specific changes in the metabolomic profile of the weanling pig gut. Objective 3) Develop and/or utilize molecular tools to understand the role of genes relevant to health, growth or intestinal function in swine and dairy with the goal of identifying targets for alternatives to antibiotic growth promotants. A. Establish in vitro approaches (intestinal pig cell lines) to model the role of specific metabolites or cytokines in gut nutrient absorption and gut immunological responses. B. Develop and apply site-specific gene modifying technologies to modify intestinal epithelial cell function and metabolism. C. Target specific bovine genes for editing that are relevant to health, milk production and milk quality.

Approach:
The unifying theme of the project is to determine ways to reduce the use of antibiotics in farm animals. Foremost is investigating the growth promotant mechanism(s) of antibiotics in the context of the pig’s gut microbiome, metabolome and proteome. To this end, we will identify alternative products and methods to replace the use of antibiotics as growth promotants in pigs, and to mitigate mastitis in dairy cattle. One potential approach to limit the use of antibiotics in farm animals is to change the expression of the animal’s genes via gene-editing. Novel antimicrobials based on bacteriophage endolysins will be tested with young pigs and as a means of early mastitis detections in dairy cows. Another approach will be transplantation of transgenically modified pig cells that secrete specific proteins conferring disease resistance. Other studies will examine the effects of promising probiotics in weanling pigs for growth support in the critical preweaning period. Coupled with this will be an examination of the weanling pig’s gut microbiome with prebiotic feeding in comparison to antibiotics. The final objective will be to establish novel pig ileal cell culture lines. Improved in vitro models would enable faster evaluations of microbe/pig gut interactions and of nutrient absorption and inflammatory responses in screenings of probiotic efficacy. Consistent in vitro models also provide a platform for testing the expression and effects of gene-editing on pig small intestine cells.