Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #129400
Title: CONTROL OF LACTATE ACCUMULATION IN A GOAT ACIDOSIS MODEL USING PREVOTELLA BRYANTII

Author
item RODRIGUEZ, FERNANDO - IOWA STATE UNIV., AMES
item Rasmussen, Mark
item ALLISON, MILTON - IOWA STATE UNIV., AMES

Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: When ruminants are shifted from forage to a carbohydrate-rich diet, lactate-producing bacteria proliferate. This lactate fermentation reduces ruminal pH, perturbs the normal rumen microbiota and endangers animal health. Our objective was to test the hypothesis that lactic acid accumulation could be inhibited by inoculating the rumen with volatile acid producing bacteria that would compete with lactic acid producing bacteria for substrate (starch). Fistulated goats were used as a rumen acidosis model. Lactic acidosis was induced by adding 1,000 g of wheat starch via a rumen fistula. Animal health, ruminal pH and VFA were monitored for 24 h. Treated animals received an inoculum of selected amylolytic bacteria (strain 25A) (10**9 CFU) just prior to starch administration. Candidate inoculum bacteria were isolated from a rapid turnover (30%/h) starch-fed fermentor that was inoculated with highly dilute rumen contents from a grain-fed cow. Ruminal pH of the acidosis control animals declined to 4.6-4.8 within 8 h after starch administration. Lactic acid concentrations in these animals were 78 mM and 100 mM at 8 and 24 h, respectively. When acute starch feeding was preceded by inoculation with strain 25A, ruminal lactate accumulation was limited (2 mM), pH declines were moderated (6.0-6.3) and concentrations of acetate, propionate and succinate were greater. A dendogram generated by cluster analysis of 16S rRNA gene sequence indicated that strain 25A phylogenetically grouped with Prevotella bryantii. Administration of the amylolytic bacterium, Prevotella bryantii 25A to goats altered rumen fermentation and directed starch fermentation away from lactate accumulation in favor of acetate and propionate production.