PSXVII-37 Effect of canola oil supplementation to AAC Mountainview sainfoin alone or in combination with grass mixtures on in vitro DMD methane production and ruminal fermentation.

摘要

This study assessed supplementing AAC Mountainview sainfoin, with 2 sources of canola oil (CO; commodity and high oleic acid variety) at 3 inclusion rates (0, 3, 5% DM), on in-vitro fermentation, DMD and CH4 production. Sainfoin was seeded alone or in combination with hybrid bromegrass at 3 seeding ratios (100, 70:30 and 50:50). An alfalfa-meadow bromegrass (AG) mixture was included as a check. This experiment was analysed as a randomised complete block design including the fixed effects of forage and CO and the random effects of run, replication and interactions between mixture, replication and CO. Forage samples were incubated at 39°C in vials containing buffered medium and rumen fluid for 48- hrs. At pre-determined timepoints, gas pressure was recorded and gas samples for CH4 determination were collected. Pure sainfoin had lower (P>0.001) DMD and higher CH4 (55.4 ml/g DMD) than all other treatments. Highest (P>0.001) DMD was observed for AG, however CH4 did not differ between sainfoin-mixtures and AG (m=51.3 ml/g DMD). CO supplementation did not have an effect on forage digestibility nor did it effect CH4 production. Fermented fluid of pure sainfoin had the highest (P>0.001) molar proportions of acetate and butyrate to propionate (a+b:p) compared to all other treatments. The lowest (P>0.001) ratio of a+b:p was observed for AG. Regardless of source or inclusion rate, CO had no effect on the molar proportions of a+b:p. In conclusion, the AG treatment had higher digestibility and produced less CH4 compared to all other sainfoin treatments, which may indicate that CT in in sainfoin had no effect on CH4 production. Moreover, regardless of rate or source, CO supplementation had no effect on forage digestibility or CH4 production.