Odor Reduction Monitoring in Swine Farms Following the Application of Domestic Commercial Microbial Products

This study evaluated the effects of commercially available microbial preparations (used as feed additives and environmental treatments) on swine farms, with a focus on odor reduction, gut microbiota, and immune responses.The results showed a significant reduction in major livestock odors, such as ammonia, volatile fatty acids, and phenolic compounds, although reductions in sulfur-based odors like hydrogen sulfide were limited.Five swine farms were selected for a ten-month study during which microbial feed additives and environmental improvement products were administered to assess their effectiveness in reducing odor emissions and altering the intestinal microbiota.Monitoring involved measurements of odorant concentrations, quantitative analysis of fecal microbiota, and microbial community profiling.A reduction in ammonia was observed, accompanied by an increase in hydrogen sulfide and other odorants.The change of metagenomics revealed a decrease in the abundance of Firmicutes from 77% to 56% and an increase in Bacteroidetes from 17% to 35% in the pig feces from the swine firms.Additionally, all farms maintained normal levels of the intestinal inflammation index.Microbial treatments led to a reduction in certain beneficial bacteria, such as Lactobacillus, but increased the abundance of short-chain fatty acid (SCFA), producing bacteria, including Ruminococcaceae, Porphyromonadaceae, and Faecalibacterium prausnitzii, suggesting improved energy metabolism and fiber degradation.Calprotectin levels (an inflammation marker) decreased in some farms, indicating potential reductions in intestinal inflammation.Despite no significant changes in total bacterial counts, species richness and diversity improved, and inflammation markers remained within normal physiological ranges.Overall, the study suggests that consistent use of microbial products, in combination with modern farm infrastructure, can improve both odor control and gut health, potentially enhancing the sustainability of swine farms and reducing community complaints.