THE EFFECT OF A MICROBIAL PRODUCT ON PRODUCTION PERFORMANCES OF FATTENING STEERS: PRELIMINARY RESULTS

The effect of a bacteria-based product (Bovilact), on ruminants production performances was studied on 32 fattening steers (150-250 kg weight category), randomly distributed in two groups (control/experimental). Both groups were fed ad libitum a diet composed of 20% corn silage and 80% compound feed (based on wheat and sunflower meal). For the experimental group, 10% of the compound feed was enriched with Bovilact (inoculated with a polyculture of acilolactic bacterias and yeasts and incubated until desired density of bacterial cells). Similar diets were fed to two fistulated cows, organized in a Latin Square design, in order to assess the effect on postprandial ruminal pH dynamics: average pH, minimum pH, maximum pH, duration of pH decrease under 6.2 threshold (t<6.2; hours), intensity ofpH decrease under 6.2 threshold (a<6.2; hours x pH units), area under pH curve (auc; hours x pH units). pH was measured 10 hours after the morning meal, with a frequency of sampling of two hours. After 36 days of experiment, inclusion of Bovilact tended to slightly improve the daily weight gain: + 4.9% in experimental group, versus control. Bovilact had no clear effect on the level of ruminal pH level but changed the shape of pH curves, suggesting an influence on microbial populations involved in carbohydrates metabolism. Further studies on the end-products of carbohydrate (VFA) are needed in order to clearly assess the effects of Bovilact at ruminal level.