Andreea Vasilachi


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

Andreea Vasilachi, C. Dragomir, Aurelia Soare

Abstract
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 of pH 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.

Key words: steers, performance, probiotics, rumen, pH

EFECTUL UNUI PRODUS MICROBIAN ASUPRA PERFORMANTELOR PRODUCTIVE ALE TINERETULUI TAURIN LA ÎNGRASAT: DATE PRELIMINARE

Andreea Vasilachi, C. Dragomir, Aurelia Soare

Rezumat
Efectul unui produs pe baza de bacterii (Bovilact), asupra performantelor productive la rumegatoare a fost studiat pe 32 de taurasi la îngrasat, categoria 150-250 kg, distribuiti aleator în doua loturi (martor/experimental). Ambele loturi au fost hranite la discretie cu o ratie formata din 20% siloz de porumb si 80% nutret combinat (pe baza de grâu si srot de floarea soarelui). La lotul experimental, 10% din nutretul combinat a fost îmbogatit cu Bovilact (inoculat cu o policultura de bacterii acidolactice si drojdii si incubat pâna la obtinerea densitatii vizate a celulelor bacteriene). Doua vaci fistulizate, organizate în patrat latin, au fost hranite cu ratii similare, în vederea determinarii efectelor produsului asupra dinamicii postprandiale a pH-ului ruminal: pH mediu, pH minim, pH maxim, durata scaderii pH-ului sub pragul de 6.2 (t<6.2; ore), intensitatea scaderii pH-ului sub pragul de 6.2 (a<6.2; ore x unitati pH), suprafata sub curba de pH (ssc; ore x unitati pH). pH-ul a fost masurat timp de 10 ore dupa furajare cu o frecventa a prelevarii probelor de 2 ore. Dupa 36 de zile de experienta, includerea Bovilact-ului a condus la cresterea usoara a sporului mediu zilnic, + 4.9% în cazul lotului experimental fata de martor. Bovilact-ul nu a condus la efecte majore asupra pH-ului ruminal dar a modificat forma curbei de pH, aceasta sugerând o influenta asupra populatiilor microbiene implicate în metabolismul glucidelor. Studiul va continua cu analiza produsilor finali ai metablismului glucidic (AGV) în vederea stabilirii cu certitudine a efectelor Bovilact-ului la nivel ruminal.

Cuvinte cheie: taurasi, performante, probiotice, rumen, pH