POTENTIALS OF PROANTHOCYANIDINS FROM TEMPERATE FORAGE LEGUMES AT DIFFERENT CONCENTRATION LEVELS TO REDUCE ENTERIC METHANE PRODUCTION USING IN- VITRO TECHNIQUES

Résumé

A study was conducted to assess the effect of proanthocyanidins (PAs) concentration at different levels from temperate forage legumes to reduce enteric methane emission in- vitro. The study was carried out at Institutes of Animal Nutrition and Physiology as well as Grass and Forage Science/Organic Agriculture Laboratories, Kiel University (CAU), Germany. PAs were extracted from leaves of four tanniferous forages; Sulla, birdsfoot trefoil, big trefoil and salad burnet during vegetative stage of growth using acetone/H2O (80:20 v/v) concentration. The PAs were measured using the ultra-performance liquid chromatography–tandem mass spectrometer (UPLC-MS/MS) method. The experimental design was a 4 (four legumes) x 3 (three tannins concentrations) factorial with 3 replicates. Results shows that Salad burnet and Birdsfoot trefoil produced highest (P<0.002) total gas, while Big trefoil had lowest amount of methane (11.72 ml/200mg). The In-vitro organic matter digestibility (IVOMD) was also lowest in Big trefoil (83.49 %). Adding 1, 2, and 3 % concentration levels has no significant (P>0.01) on total gas produced and IVOMD. However, PAs included at 3 % concentration has lower (P<0.01) methane production compared to the other levels. It is concluded that tannins from Big trefoil had lowest methane among the legumes when included at 3 % concentration level to grass samples.