Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 3/11/2002
Publication Date: 6/1/2002
Citation: Varel, V.H. 2002. Influence of plant-derived extracts on swine gastrointestinal microorganisms, pathogens, and odor emissions. In: Martin, S.A., editor. Gastrointestinal Microbiology in Animals, 2002. Research Signpost, Kerala, India. p 89-101.
Technical Abstract: Swine production has become highly concentrated and industrialized. Excess feeding of nutrients and feeding of therapeutic antibiotics has generated environmental contamination of the air, water, and land, and may have produced antibiotic resistant microorganisms. Many of these problems are related to the ecology and metabolism of the microorganisms in the pig intestinal tract and those in the stored, excreted waste. More is known about the microorganisms in the intestinal tract than about those in the stored waste; however, recent studies using bacterial ribosomal sequences suggest that the majority of these sequences are not related to known microorganisms. This suggests that much more basic work is needed to understand these microbial ecosystems to come up with precise solutions to the environmentally associated problems. Solutions that are less precise may come from controlling the microbial activities in these ecosystems with antimicrobial plant-derived oils. Limited studies are beginning to indicate that natural plant extracts added to feeds may enhance animal growth performance without the use of antibiotics. Other studies indicate that plant derived oils, thymol and carvacrol, can be used to eliminate pathogenic microorganisms from stored waste and reduce odor emissions. Multi-disciplinary research efforts which emphasize nutrient management and environmental stewardship will greatly assist the swine production industry.