TY - JOUR AU - Tous-Rivera, Karla AU - Valencia, Elide AU - Rodríguez, Abner A. AU - Randel, Paul F. AU - Adegbola, Adesogan PY - 2010/04/01 Y2 - 2024/03/28 TI - Exogenous fibrolytic enzymes affect chemical compostition, animal intake and digestibility of guinea grass hay (Panicum maximum Jacq.) JF - The Journal of Agriculture of the University of Puerto Rico JA - JAUPR VL - 94 IS - 1-2 SE - Articles DO - 10.46429/jaupr.v94i1-2.2590 UR - https://revistas.upr.edu/index.php/jaupr/article/view/2590 SP - 131-146 AB - Two experiments were conducted for determining effects of applying exogenous fibrolytic enzymes to guineagrass hay (GH) [<em>Panicum maximum</em> Jacq. (= U<em>rochloa maxima</em> (Jacq.) R. Webster)] upon chemical composition, voluntary intake (VI), digestibility of various chemical fractions, and apparent and true dry matter (DM) degradability. The enzymatic products used were Promote<sup>NET </sup>and Biocellulase<sup>A-20</sup>, derived from <em>Trichoderma longibratum</em> and <em>Aspergillus reesei</em>. These products contain mainly cellulase and xylanase. In the first experiment, nine mature Blackbelly x creole crossbred rams of 26.8 kg mean body weight (BW) were used in a 3 x 3 Latin Square design, with 18-d periods. Treatments consisted of untreated hay (control), hay treated with Promote<sup>NET</sup>, and hay treated with Biocellulase<sup>A-20</sup>, applied by spraying 24 h prior to feeding. Daily hay offerings were at 4% of BW on a dry matter (DM) basis. Enzyme treatment increased contents of DM and crude protein (CP) in the treated GH in comparison with those contents of the untreated hay. A tendency to reduce neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose concentrations through the enzymatic treatments was also observed but was not significant (P &gt; 0.05). The VI of DM of hays treated with Biocellulase<sup>A-20</sup><span style="vertical-align: super;"> </span>and Promote<sup>NET </sup>(1,139 and 938 g DM/d, respectively) exceeded that of the control (921 g DM/d).The VI of CP, NDF and ADF were higher for hay treated with Biocellulase<sup>A-20  </sup>than for GH untreated or treated with Promote<sup>NET</sup>. Rams fed enzyme-treated hay had higher (P &lt; 0.05) DM intake as a percentage of BW when compared with those fed untreated GH (4.06% for Biocellulase<sup>A-20 </sup>0, 3.15% for Promote<sup>NET</sup>, and 2.86% for the control). Apparent DM digestibility increased (P &lt; 0.05) by 5.89 and 4.24 percentage units for Biocellulase<sup>A-20 </sup>- and Promote<sup>NET</sup><span style="vertical-align: super;"> </span>-treated hays in comparison with that of the control (50.12%). Significant increases over the control were observed in digestibility of three other fractions for GH treated with Biocellulase<sup>A-20 </sup>and Promote<sup>NET </sup>(CP, 3.23 and 3.18; NDF, 7.96 and 4.31; ADF, 7.69 and 7.9 percentage units). Digestibility of dry matter, CP and ADF did not differ (P &gt; 0.05) between enzymatic treatments, whereas NDF digestibility was higher (P &lt; 0.05) for GH treated with Biocellulase<sup>A-20</sup>. In the second experiment, apparent dry matter degradability (IVDMDA) and true dry matter degradability (IVDMDT) were found to be higher (P &lt; 0.05) for GH treated with both enzymes than for those of the control (IVDMDA by 2.75 percentage units for Biocellulase<sup>A-20</sup>, 2.12 for Promote<sup>NET</sup>; IVDMDT by 2.42 and 1.73 units, respectively). These results indicate that application of fibrolytic enzymatic complexes to low-quality tropical grass hay can improve the nutritional value substantially. ER -