“…Despite the lack of significant difference in propionic acid concentrations, the combination crude glycerine with essential oil promoted an increase of 17% in this acid, fact that decreased the C2: C3 ratio in the rumen. Although there are also evidence that crude glycerine may have a detrimental effect on the growth of structural carbohydrate fermenting bacteria (AbuGhazaleh, Abo El‐Nor, & Ibrahim, ; Roger, Fonty, Andre, & Gouet, ), resulting in reduced fibre digestibility and CH 4 production (van Cleef et al, ; Homem Junior et al, ; Paschoaloto et al, ), crude glycerine does not impair the consumption, performance or carcass characteristics of feedlot cattle (van Cleef et al, ) and, when combined with essential oil, has shown even better results (Cruz et al, ; Prado et al, ; Silva et al, ; Valero, Prado, et al, ; Valero, Torrecilhas, et al, ).…”