Theme 2-3: Forage Production and Utilization--Poster Sessions
Description
The study was conducted to evaluate the interactive role of bacteria and fungi on forage degradation in vitro. Samples of Cynodon spp. were incubated in a 48-h in vitro gas assay with incubation medium containing or not antimicrobial substances. Treatments were: antibiotic (Ab), antifungal (Af), negative control (i.e. without antimicrobials) or positive control (i.e. with both Ab and Af). Three replicate assays were conducted and, in each assay the gas volume was measured at 3, 6, 9, 12, 24, 36 and 48 h of incubation. Data of cumulative gas production in each flask in each assay was fitted to a one-pool logistic model which generated three kinetic parameters: total gas production, rate of gas production and lag time. For statistical analysis, data of triplicates in each run were averaged and each run was considered a replicate. All variables were significantly affected by treatments (P < 0.05). Compared to negative control treatment, Ab decreased total gas production and the rate of gas production by 26 and 13 %, respectively, and increased the lag time by 5.5 hours. The inclusion of Af also decreased total gas production and the rate of gas production by 5 and 29%, respectively, whereas decreased the lag time by 1 hour. When both Ab and Af were included in the incubation medium, gas production was almost completely inhibited and no convergent data of fermentation parameters was generated. In conclusion, bacteria had a major role on forage degradation what, however, was increased by fungi activity. The mechanisms by which fungi interact with bacteria for degrading forage into the rumen needs to be elucidated.
Included in
The Role of Bacteria and Fungi on Forage Degradation in Vitro
The study was conducted to evaluate the interactive role of bacteria and fungi on forage degradation in vitro. Samples of Cynodon spp. were incubated in a 48-h in vitro gas assay with incubation medium containing or not antimicrobial substances. Treatments were: antibiotic (Ab), antifungal (Af), negative control (i.e. without antimicrobials) or positive control (i.e. with both Ab and Af). Three replicate assays were conducted and, in each assay the gas volume was measured at 3, 6, 9, 12, 24, 36 and 48 h of incubation. Data of cumulative gas production in each flask in each assay was fitted to a one-pool logistic model which generated three kinetic parameters: total gas production, rate of gas production and lag time. For statistical analysis, data of triplicates in each run were averaged and each run was considered a replicate. All variables were significantly affected by treatments (P < 0.05). Compared to negative control treatment, Ab decreased total gas production and the rate of gas production by 26 and 13 %, respectively, and increased the lag time by 5.5 hours. The inclusion of Af also decreased total gas production and the rate of gas production by 5 and 29%, respectively, whereas decreased the lag time by 1 hour. When both Ab and Af were included in the incubation medium, gas production was almost completely inhibited and no convergent data of fermentation parameters was generated. In conclusion, bacteria had a major role on forage degradation what, however, was increased by fungi activity. The mechanisms by which fungi interact with bacteria for degrading forage into the rumen needs to be elucidated.
