| Popis: |
Problem statement: The aim of the present study was to characterize a nd differentiate the effects of addition of flavomycin or monensin on ru minal fermentation and degradability as well as on total digestibility in bovine. Approach: Twelve non-pregnant and non-lactating cows (736 kg of BW) were randomly assigned to three treatments: control , flavomycin (20 mg animal -1 day -1 ) and monensin (300 mg animal -1 day -1 ). The trial lasted 21 days. The last 10 days were used for external marker administration (15 g of chromic oxide animal -1 day -1 ). The last 5 days of the trial were used for feces collection and evaluation of corn grain, soybean me al or sugarcane ruminal degradability and the 21st day was used for ruminal fluid sampling. Results: Monensin increased 27.2%, on average, propionate molar proportion at 0, 4, 6, 8, 10 and 12 h after f eeding, compared to control and flavomycin groups. When compared to control, flavomycin reduced the degradation rate of soybean meal CP in 31.0%, decreasing the effective degradability when passage rates of 5 and 8% h -1 were used. Dry matter intake, pH, total Short Chain Fatty Acids (tSCFA) o r ammoniacal Nitrogen (NH 3-N) concentration were not influenced by the addition of either antib iotics. Effective degradability of sugarcane NDF wa s not influenced by the use of either antibiotic; nei ther were the TDN nor the digestibility of DM, CP, EE, NFE, ADF, NDF, GE or starch of the diet. Conclusion/Recommendations: In the present study, it was possible to show the beneficial effects of m onensin but not of flavomycin, on rumen fermentation. |
