This study evaluated the effects of different concentrations of 30% propolis ethanol extract (PEE) and sodium monensin on the intake of dry matter, nutrient digestibility and ruminal fermentation and hematological parameters in sheep. Six adult castrated male sheep fistulated in the rumen were assigned to a 6 x 6 Latin square design. The addition of PEE or sodium monensin to the diet did not change the digestibility coefficients of dry matter (79.4%), crude protein (77.0%), neutral detergent fiber (76.1%), acid detergent fiber (69.7%), hemicellulose (80.9%), and organic matter (79.4%). Sheep fed diets with inclusion of sodium monensin showed 11.3% reduction in dry matter intake (1.76 kg day-1) compared to those which received PEE (2.00 kg day-1). The inclusion of additives to the diet influenced ruminal pH: higher values were observed in sheep fed sodium monensin (6.1). Mean levels of ammonia nitrogen (7.3 mg dL-1) were similar between treatments. Biochemical serum parameters of glucose (59.4 mg dL-1), urea (8.9 mg dL-1) total protein (6.8 g dL-1) and albumin (2.5 g dL-1) were within the reference range for the ovine species. Sodium monensin was more efficient to maintain ruminal pH at higher levels and to reduce the dry matter intake. However, the addition of PEE did not affect the nutrient digestibility in sheep fed 50:50 forage: concentrate ratio.

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.