Probiotics in Ruminants

The vaginal microbiota of cows comprises several LAB species including Lactobacillus spp., Pediococcus spp., Leuconostoc spp., and Weissella spp., some of which were isolated and tested for their probiotic capacities against urogenital infections (Otero et al. 2000 Wang et al. 2013a). 

Pioneering works isolated several Streptococcus sp. and Lactobacillus sp. strains from the vagina of healthy cows (Otero et al. 2006) and reported promising results using Lactobacillus gasseri isolates, which showed inhibitory activity against Staphylococcus aureus in vitro (Otero and Nader-Macias 2006). 

Uterine microbiota of cows was also recently investigated and showed a huge diversity in healthy cows compared to metritic and endometritic ones. Regardless of the health status, the uterine microbiota is mainly composed of members of the phyla Bacteroidetes, Fusobacteria, Firmicutes, Proteobacteria, and Tenericutes (Santos and Bicalho 2012). 

Acidosis Subacute ruminal acidosis (SARA) is a digestive disorder characterized by the instability of the microbial ecosystem and by fermentations that lead to lactate, butyrate, and/or propionate rather than acetate (i.e., lactic-, butyric-, and propionic- SARA). It is a major concern in cattle health and welfare. In addition to, or besides the use of, chemical buffers and ionophores, the use of probiotics as feed additives has been investigated as a strategy to balance the ruminal microbiota and fermentation, to stabilize the ruminal pH, and therefore to prevent SARA. Most of the probiotics used in this context contain yeasts (mainly 5. cerevisiae) as the main active microorganism (Desnoyers et al. 2009). Prevotella bryantii, a Gram negative bacterial species 

Scientific literature on bacterial probiotics containing LAB and propionic acid bacteria (PAB) reports variable and sometimes contradictory results, which can be attributed to the instability of the microbiota. A preliminary determination of the acidosis type helps in choosing the most relevant probiotic microorganisms and ensures better prevention. It was thus shown that a combination of Propionibacterium sp. and Loot, plantarum or Lact. rhamnosus were inefficient against lactic acidosis whereas it showed promising results in minimizing butyric and propionic SARA (Lettat etal. 2012). 

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In monogastric animals, strains of Lactobacilli, Bacillus subtiUs and Streptococci have been used as probiotics. In ruminant animals, the application of yeast (Saccharomyces cerevisiae) in the form of live culture, or dead cells with culture extracts, has proved successful in beneficially modifying rumen fermentation. 

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