RESUMO -Avaliaram-se os efeitos da utilização de produtos contendo própolis em duas concentrações (B e C) e duas extrações alcoólicas (1 e 3) e de monensina sódica em dieta à base de forragem sobre o consumo, a digestibilidade total e parcial e as características ruminais em bovinos. Utilizaram-se quatro bovinos da raça Holandesa, castrados, com peso corporal de 221 ± 21 kg, canulados no rúmen, em delineamento experimental quadrado latino 4 × 4. As dietas experimentais foram constituídas de 72,5% de volumoso e 27,5% de concentrado e apresentaram 14,4% de PB e 67% de nutrientes digestíveis totais (NDT), diferindo apenas quanto à presença de aditivos. Os consumos médios de matéria seca e nutrientes, não foram afetados pelas dietas, exceto o de NDT, que foi maior nos animais alimentados com a dieta controle. O fornecimento dos aditivos, principalmente própolis, reduziu a digestibilidade total de matéria seca, proteína bruta e NDT.A digestibilidade total da fibra em detergente neutro (FDN) foi semelhante entre aditivos e menor que nos animais controle.A inclusão de própolis refletiu em menor pH ruminal e maiores produções de acetato e AGV totais e a monensina propiciou a menor razão acetato:propionato. A adição dos aditivos avaliados tem efeito negativo sobre a concentração e consumo de energia digestível de dietas à base de forragem fornecida para bovinos em crescimento.Palavras-chave: ácidos graxos voláteis, digestibilidade parcial, nitrogênio amoniacal, pH ruminal, taxa de diluição Digestibility and ruminal parameters of diet based on forage with the addition of propolis and sodium monensin for steers ABSTRACT -It was evaluated the effects of using products containing propolis in two propolis concentrations (B and C) and two alcoholic extractions (1 and 3) and sodium monensin in forage based diet on intake, total and partial digestibility and ruminal characteristics in cattle. It was used four Holstein castrated bovines, with body weight of 221 ± 21 kg, implanted with ruminal cannulla, in a 4 × 4 Latin square experimental design. The experimental diets were composed of 72.5% roughage and 27.5% concentrate and had 14.4% crude protein and 67% of total digestible nutrients (TDN), only differing to the presence of additives. The average intake of dry matter and nutrients did not differ among diets, except for the intake of TDN that was higher for animal fed control diet. The supply of additives, mainly propolis, reduced the total digestibility of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN). The total digestibility of neutral detergent fiber was similar among additives and it was lower than the control animals. The inclusion of propolis reflected in lower pH and production of acetate and total volatile fatty acids and monensin resulted in lower acetate:propionate ratio. The addition of the evaluated additives has negative effect on the concentration and intake of digestible energy of roughage based diets for growing cattle.

SUMMARYThe purpose of this study was to evaluate three internal markers of digestibility: indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF), by comparing them with chromium oxide as external marker in the estimation of omasal and fecal flows and dry matter intake (DMI) of diets containing 60% of sugar cane silage and 40% concentrate. Four buffalos and four bovines, fitted with ruminal cannula, were used in a replicated split-plot 4 x 4 Latin square design with 2 species (buffalo and bovine) and 4 diets distributed among plots and 4 markers (Cr 2 O 3 , iADF, iNDF, and iDM) as subplots. Omasal flows differed between markers and animal species (interaction p<0.05). In buffalos, but not in cattle, there were large differences between omasal flow estimates from MSi and Cr 2 O 3 , while iNDF and iADF underestimated omasal flow in both species although to larger extent in buffalo than in cattle Fecal output estimates differed between markers similarly for both species, with all internal markers differing from Cr 2 O 3 . Estimates of IMS derived from Cr 2 O 3 as faecal output markers, differed between internal digestibility markers to similar exent for all diets and species. Dietary IMS estimated from MSi and iADF did not differ from observed values, suggesting their potential as digestibility markers in the estimation of intake while Cr 2 O 3 and iDM could be used to estimate omasal flows in cattle. INTRODUÇÃOOs indicadores têm sido utilizados como