SUMMARY
This study evaluated the influence of the propolis ethanolic extract (PEE) on gas production and in vitro degradability of sheep diets. Five experimental diets (treatments) were evaluated: without addition of PEE; 6 mL PEE; 12 mL PEE; 24 mL PEE and 36 mL PEE/kg concentrate. The experimental diet consisted of 50% elephant grass (Pennisetum purpureum) and 50% concentrate. There was a quadratic effect (P <0.05) for the volumes of total gas production (Vt), gases produced by the rapid degradation fractions (Vf1), and for in vitro degradability at 120 hours (Deg120), where the lowest values of Vt, Vf1 and Deg120, were found for the inclusion of 9.4 mL PEE/kg concentrate. Gas production by fermentation of the slow degradation fraction (Vf2) presented a mean of 25 mL/g DM (P <0.05). The colonization time of food particles (λ) significantly reduced (P<0.05) with increasing inclusion of PEE. Thus, it can be concluded that the PEE up to the inclusion of 9.4 mL/kg concentrate was efficient in inhibiting in vitro total gas production and from the fractions of rapid degradation by 9.9 and 15.3%, respectively, in addition to promoting a reduction of 5.3% in degradability after 120 h incubation in diets with a concentrate: forage ratio of 50:50. Thus, the inhibition in gas production was proportionally greater than the reduction of degradability.
Keywords:
colonization time; degradation; fermentation
