Encapsulated phytogenic oils enhance in vitro rumen fermentation and reduce methane emissions.

Abstract

BACKGROUND: This research aimed to investigate bioaccessibility of garlic oil extract (GOE) and riceberry rice bran oil extract (RBRBOE) and to enhance the stability and delivery of plant-derived essential oils. Two EOs were used to formulate through encapsulation techniques of microencapsulated black soldier fly (BSF) protein with a GOE matrix, (mBSF-GOE), and a nanoemulsified RBRBOE, (nRBRBOE). A completely randomized design was used for the treatments, with various ratios of feed additives between the mBSF-GOE and nRBRBOE supplementations at 0:0, 6:0, 4:2, 2:4, and 0:6&#xa0;mg in diet, with the R: C ratio at 60:40 using in vitro gas study. RESULTS: The combination of mBSF-GOE and nRBRBOE at 4:2&#xa0;mg for 12 and 24&#xa0;h after fermentation had a significant impact on several factors (p&#x2009;<&#x2009;0.01, <&#x2009;0.05), including gas kinetics, cumulative gas production (96&#xa0;h), in vitro dry matter degradability (IVDMD), and ruminal fermentation products. Specifically, the levels of propionate (C3) and total VFAs went up, while ruminal methane (CH) production decreased by 48.2%. Subsequently, there was no negative effect (p&#x2009;>&#x2009;0.05) on the ruminal pH, ammonia nitrogen (NH-N) concentration, or the dynamics of the rumen microbiota population, while significantly decreasing the methanogen population in terms of Methanobacteriales (up to 3.3% after 24&#xa0;h) (p&#x2009;<&#x2009;0.01). CONCLUSIONS: Based on this study, it could be concluded that the supplementation of mBSF-GOE combined with nRBRBOE-based bioactive components could potentially be used as a ruminant feed enhancer to enhance fermentation efficiency and as technological feed additive substances to inhibit the methanogen population while mitigating CHproduction.