Effects of Direct-Fed Microbials on Pig Fecal Flora and Volatile Fatty Acid (VFA) Densities and VFA-Producing Microbe

摘要

This work was carried out to investigate the effect of a direct-fed microbial (DFM) known as "DMP-odor" on changes in microbia! fecal flora and its inhibitory effect on a volatile fatty acid (VFA) producing microbe responsible for malodors in pig feces. Bifidobacterium (p<0.05), a fiber fermentative bacteria which also has an inhibitory action against the growth of pathogenic strains, resulted in high recovery rate in the fecal flora than in the control. The populations of Enterobacteriaceae (p<0.05)and Cfostridia (p<0.001) in fecal flora decreased compared to that of the control. The inhibition effect of DMP-odor on the intestinal VFA-producing microbe known as Clostridium acetobutylicum occurred after 38 h when it was combined with the culture extracts of nine malodorant-utilizing microbes. The death phase started after 65 h incubation. These results indicate that some substances produced by the malodorant-utilizing microbes can inhibit the growth of C. acetobutylicum. The feces of pigs fed withDMP-odor contained less VFA than that of the control. Acetic acid, propionic acid, iso-butyric acid, iso-valeric acid and valeric acid had a decreased (P < 0.05) concentration of 60.88%, 78.62%, 44.96%, 76.49% and 69.02%, respectively, compared to the control group. Therefore, the influence of DMP-odor on the dynamics of fecal flora can be beneficial to animal performance, in addition, DMP-odor can diminish potential malodorfrom feces in pig barns.