Abstract #W33
Section: Forages and Pastures (posters)
Session: Forages and Pastures 2
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Exhibit Hall A
Session: Forages and Pastures 2
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Exhibit Hall A
# W33
The effects of recombinant bacterial expansin-like protein and a fibrolytic enzyme on in vitro nutrient digestibility and preingestive hydrolysis of alfalfa silage.
J. E. Blajman1, A. A. Pech-Cervantes*2, M. Irfan3, C. F. Gonzalez3, D. Vyas2, K. G. Arriola2, N. Dilorenzo4,2, Y. Jiang2, F. X. Amaro2, A. T. Adesogan2, 1National Institute of Agricultural Technology EEA Rafaela, National Council of Scientific and Technical Research, Rafaela, Argentina, 2Department of Animal Sciences, University of Florida, Gainesville, FL, 3Department of Microbiology and Cell Science, Gainesville, FL, 4Department of Animal Sciences, North Florida Education Center University of Florida, Marianna, FL.
Key Words: alfalfa silage, enzyme, expansin
The effects of recombinant bacterial expansin-like protein and a fibrolytic enzyme on in vitro nutrient digestibility and preingestive hydrolysis of alfalfa silage.
J. E. Blajman1, A. A. Pech-Cervantes*2, M. Irfan3, C. F. Gonzalez3, D. Vyas2, K. G. Arriola2, N. Dilorenzo4,2, Y. Jiang2, F. X. Amaro2, A. T. Adesogan2, 1National Institute of Agricultural Technology EEA Rafaela, National Council of Scientific and Technical Research, Rafaela, Argentina, 2Department of Animal Sciences, University of Florida, Gainesville, FL, 3Department of Microbiology and Cell Science, Gainesville, FL, 4Department of Animal Sciences, North Florida Education Center University of Florida, Marianna, FL.
The aim of this study was to examine if effects of an exogenous fibrolytic enzyme (EFE) on in vitro digestibility and preingestive hydrolysis of alfafa silage can be synergistically increased by different doses of a recombinant bacterial expansin-like protein (BsEXLX1). Treatments were arranged in a 2 × 4 factorial arrangement with 2 levels of a cellulase-xylanase EFE (0, 2.3 mg/g DM) and 4 levels of BsEXLX1 (0, 0.106, 0.212, and 0.424 mg/g DM). In Experiment 1 (E-1), dried, ground (1 mm) alfalfa silage samples were preincubated in sodium citrate buffer for 1 h at room temperature in quadruplicate with or without the treatments followed by incubation in rumen fluid for 24 h at 39°C. Gas production (GP), in vitro true digestibility, CH4 emissions, and VFA profile were measured after 24 h. In Experiment 2 (E-2), alfalfa silage was incubated with or without the treatments in deionized water containing 0.02% sodium azide for 24 h at 25°C and preingestive hydrolysis was measured. Data were analyzed using NLME package of R studio with EFE, BsEXLX1 and interaction as fixed effects and run as a random factor in the model. In E-1, EFE increased GP (P = 0.02) and reduced pH (P < 0.01) compared with the control; however, no effects were observed on in vitro DM, NDF, and ADF digestibility. Similarly, the combination of EFE and BsEXLX1 had no effects on digestibility of DM, NDF, and ADF or VFA and NH3-N concentrations. Methane emissions tended to increase with EFE (P = 0.08) treatment while BsEXLX1 supplemented at 0.212 and 0.424 mg/g DM significantly increased CH4 emissions (P < 0.01), compared with the control. During preingestive hydrolysis (E-2), EFE increased DM, NDF, ADF and HEM hydrolysis (P < 0.01); however, no synergistic improvements were observed when BsEXLX1 was added. Adding EFE increased release of reducing sugars compared with control (P < 0.01) but no effects were observed by adding BsEXLX1 (P = 0.80). In conclusion, EFE increased preingestive hydrolysis of alfalfa fiber but adding BsEXLX1 did not synergistically increase the response.
Key Words: alfalfa silage, enzyme, expansin
