Testing of Probiotic Bacteria for the Elimination of Escherichia coli O157:H7 in Cattle

Probiotic bacterium (Lactobacillus acidophilus; NPC 747 and NPC 750) was added to cattle feed to determine its effect on the elimination or reduction of E. coli O157:H7 in cattle. The probiotic bacterium significantly decreased the number of cattle shedding E. coli O157:H7, and had either no effect or slightly improved the feedlot performance of finishing beef steers.

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Objectives

To determine the efficacy of probiotic lactic acid bacteria (LAB) fed to cattle as a daily feed supplement with respect to the following areas: 1) shedding of E. coli O157:H7 by the live animal; 2) contamination of the carcasses during slaughter; and 3) effects on body weight gain and feed intake.

Conclusions

Cattle with certain probiotic cultures (two strains of Lactobacillus acidophilus; NPC 747 and NPC 750) decreases the incidence of E. coli O157:H7 in the feces of finishing beef cattle. Initially both cultures resulted in significant (P < .05) reductions in incidence. At the end of the study, the NPC 747 treatment was the most effective in reducing the incidence of E. coli O157:H7. Feeding the NPC 747 and NPC 750 probiotic cultures tended to improve feed:gain ratio when final body weight was calculated from hot carcass weight and the overall average dressing percent. Carcass characteristics were minimally affected by feeding the two cultures. Based on these results, feeding such microbial cultures to decrease fecal shedding of E. coli O157:H7 should either have no effect or slightly improve performance by finishing beef steers.

Deliverable

This study demonstrated that cattle feed supplemented with two strains of probiotic reduces fecal shedding of E. coli O157:H7, while having either little or no negative impact on performance.