Effects of an Essential Oil Blend on In Vitro Methane Production, In Vitro and In Vivo Nutrient Digestibility, Growth Performance, and Meat Quality in Lithuanian Blackface Lambs.

Essential oil-based feed additives have been proposed as a practical strategy to mitigate enteric methane emissions in ruminants, but their effects are not always consistent. The objective of this study was to evaluate the effects of dietary supplementation with an essential oil blend on in vitro methane production, rumen fermentation, nutrient digestibility, growth performance, carcass traits, and meat quality in Lithuanian Blackface lambs. We hypothesized that supplementation would induce measurable changes in in vitro methane production and selected rumen fermentation variables, while growth performance and technological meat quality would remain comparable between treatments. Sixty Lithuanian Blackface lambs were allocated to control (C) and treatment (T) groups (30 lambs per group). The C group received a basal diet, and the T group received the same diet supplemented with an essential oil blend, Agolin Ruminant, at a dose rate of 0.1 g/animal/day, consisting of linalool, eugenol, geranyl acetate, and geraniol. An in vitro rumen fermentation assay was performed using rumen fluid pooled within both dietary groups from multiple lambs and incubated as a single batch with four replicate fermentation flasks per treatment (