Advances in the design of a novelty veterinarian product containing

MARIA CLAUDIA OTERO; CESAR A. OVEJERO; MARIA ELENA F¨¢TIMA NADER

Tucuman

Congreso; Reunion Anual SAMIGE; 2011

SAMIGE

Metritis in cows increases herd health costs, reduces the reproductive efficiency, the conception rate (extra inseminations are required) and the feed intake, and also causes a reduction in milk production. The probiotic lactobacilli therapy provides a valid alternative to the antibiotic application for the prevention or treatment of these infections. Four autochthonous strains, i.e. Lactobacillus gasseri CRL1412, Lactobacillus gasseri CRL1421, Lactobacillus gasseri CRL1460 and Lactobacillus delbrueckii subsp. delbrueckii CRL1461 were selected by the adhesion to bovine vaginal cells, the inhibition of metritiscausing pathogens and by their technological properties (resistance to freeze-drying process stress conditions and shelf-life period in two pharmaceutical forms). In this work, the effects of natural substances with active action on the impaired epithelium and its resident microbiota, were evaluated on the growth kinetic of these microorganisms to be included in the design of a pharmaceutical product. A complete factorial experimental design was applied to determine the effect of three natural substances at different concentrations: ascorbic acid (30, 20 and 10 mg/mL), inulin (15, 10 and 5 mg/mL) and Matricaria chamomilla extract (10 and 5 mg/mL) on the growth parameters of all the tested strains. Growth was evaluated in modified MRS medium at 37¡ãC. The O.D. at 540 nm was determined at 30 min intervals during 14 h, and the increase in biomass, the maximal growth rates and the length of lag and stationary phases were calculated. The experimental procedure was repeated three times. The maximal growth rate was significantly (p ¡Ü 0.005) affected by the substance added to the culture medium, the effect being different in each strain (interaction between strain x substance, p ¡Ü 0.005). Inulin significantly increased the growth rate, mainly in the CRL 1412 strain. The increase in biomass was affected by the type of substance, but the response depended on the concentration and on the microorganisms (interaction strains x substance and substance x concentration, p ¡Ü 0,005). The main effect was observed on the growth of CRL 1421. The time of lag phase was specific for each microorganism and it was independent of the other factors. The length of the stationary phase was significantly (p ¡Ü 0,05) shortened with inulin, being CRL 1421 and CRL 1461 faster than other strains. The efficacy of the probiotic treatment depends on the viability of the microorganisms in the pharmaceutical formula during the shelf life and up the arrival to the target site in the animal. These results will allow the adequate design of a probiotic product by the combination of beneficial microorganisms with natural substances to be applied in the bovine reproductive tract. This could be used in organic farmers or other safe production systems.