Novel Mucosal Vaccines to Improve Immune and Health Status of Periparturient Dairy Cows and Increase their Productive Potentials

  • Author / Creator
    Iqbal, Summera
  • The transition period is critical for the health and productivity of dairy cows. Feeding high-grain diets immediately after parturition is necessary to support high milk production. However, high-grain diets are associated with acidic rumen pH and alterations in the composition of rumen microbiota in favor of pathogenic Gram-negative and Gram-positive bacteria which releases considerable amounts of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in the rumen fluid. There is evidence for translocation of LPS into the host systemic circulation causing multiple metabolic and immune disturbances; however, no reports related to the fate of LTA in the rumen have been reported. Both LPS and LTA have been implicated in the etiopathology of multiple diseases in dairy cows and other animals. However, no strategies on how to prevent their deleterious effects have been explored so far in dairy cows. We hypothesized that mucosal (i.e., oral or nasal) vaccination against LPS and LTA before parturition, would stimulate mucosal immunity and confer protection to dairy cows. The overall aim was to enhance the immune competence and lower the occurrence of most frequent periparturient diseases after parturition. To reach this goal two studies were conducted. In study 1, 100 dairy cows were vaccinated several times oronasally either with saline (controls) or with increasing doses of LPS from Escherichia coli 0111:B4 before parturition. Thirty cows out of 100 were selected for intensive sampling. Results from this study indicated that oronasal treatment with LPS modulated plasma metabolic and immune profiles, increased total salivary and vaginal mucus immunoglobulin-A (IgA), lowered the incidence of selected periparturient diseases, and improved overall productivity of dairy cows. In study 2, 30 transition dairy cows were treated several times orally before parturition either with saline (controls) or with increasing doses of LPS from E. coli 0111:B4 and a flat dose of LTA from Bacillus subtilis. Results from this trial demonstrated that the treatment increased salivary and vaginal mucus total IgA, modulated selected plasma metabolites, decreased acute phase proteins and pro-inflammatory cytokines as well as lowered the incidence of lameness, metritis, and retained placenta. Results of these studies are encouraging and warrant further research.

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    Doctor of Philosophy
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