Andrej Lavrencic1, Ana Backovic2, Bruno Stefanon3
1. Ass. Professor University of Ljubljana - Department of animal nutrition
2. Ana Backovic, R&D Manager, Laboratori Turval Italia
3. Professor University of Udine - Dept. of Agrifood, Environmental and Animal Science
Background: Probiotic Lactic Yeast®, Kluyrveromyces marxianus fragilis B0399 is commonly used feed additive for diary cows and meet beef nutrition due to its capacity to improve feeding efficacy and production performances of animals. Besides, this lactic acid yeast originating from kefir (traditional fermented milk from Eastern Europe) is able to ameliorate the health condition of animals through demonstrated mechanisms that regard both immunomodulatory effects and improvement of the immune status as well as promotion of intestinal health, gut microflora balance and microflora establishment in the young animal. Reduced impact of stresses. Its decadal use on farms has also shown beneficial effect of this yeast on rumen pH stabilization (prevention of acidosis) that may lead to changis in eating behavior and shorter inter-meal intervals.
Aim of the study: The purpose of this preliminary in vitro study performed at University of Ljubljana - Department of animal nutrition, in collaboration with University of Udine - Dept. of Agrifood, Environmental and Animal Science, was to evaluate the effect of feeding Kluyveromyces B0399 on the rumination/ fermentation rates, relative gas kinetics and production of VFAs (volatile fatty acids) by means of “artificial rumen”.
Method: The first data was obtained from in vitro fermentation with Kluyrveromyces B0399, using a complete diet for dairy cattle (VL) and for beef cattle (TS). The probiotic lactic yeast was incubated with buffered rumen fluid in following concentrations: 0, 17 and 33 mg/30 ml, which correspond to 0 (control), 100 and 200 g /animal per day of probiotic yeast preparation in order to simulate the effect of additive when feeding directly to the animal. For the experimental purposes the commercial additive was 10 x diluted with inactivated dried yeast Kluyrveromyces B0399.
Results: Supplementation with yeast resulted in a significant reduction of acetic acid at a dose of 200 for the dairy cows diet (VL diet) and at doses 100 and 200 for the bull starter diet (TS diet). This reduction was compensated by a significant increase in propionic acid at the 200g /head/day dose for both the VL diet and the TS diet. The in vitro production of methane (CH4, mmol) tended to be linearly lower for the VL diet. Similarly for the TS diet, doses of 100 and 200 recorded a similar decrease in methane production.
Conclusion: This preliminary results, that should be confirmed both in vitro and subsequently in vivo, point towards a positive action of the probiotic on the production of methane with a possible reduction in the emissions of this climate-altering gas in farms.