53  Effect of Aspergillus Niger and Oryzae on the digestibility of Coastal Bermudagrass and Teff hay in horses

The objective of this study was to evaluate the effect of a functional feed additive (Aspergillus Niger and Oryzae; MaxFiber, Provida Supplements, Germany; MF) on nutrient digestibility and VDMI of Teff (T) and Coastal Bermudagrass (B) hays in horses. A. Oryzae and A. Niger have been observed to increase DM and CP digestibility in cattle and pigs. Four mature, stock type geldings were used in a 4 × 4 Latin Square design experiment. Treatments were B, T, B plus 10 g MF (BMF), T plus 10g MF (TMF). Each period consisted of a 3-d dietary acclimation, followed by a 17-d voluntary intake phase, and a 72-h total fecal collection. Samples were analyzed for NDF using NIR (Dairyland Laboratories, Inc. Arcadia, WI) and proximate analysis (Servi-Tech Laboratories, Amarillo, TX). Data was analyzed using the Mixed Procedure of SAS v. 9.4 (SAS Institute, Inc., Cary, NC), with horse, period and treatment as main effects. Means were compared using Least squares means with Tukey PDIFF adjustment to compare treatment means with significance declared at P < 0.05. There was an effect of treatment (P = 0.02) on mean apparent DMD, with T (52.58%) and TMF (53.78%) greater than B (35.29%). Additionally, mean apparent DMD of TMF (53.78%) was greater than BMF (36.48). Also, DMD of T (52.58%) tended (P = 0.052) to be higher than BMF (36.48%). There was an effect of treatment (P < 0.01) on overall mean apparent CP digestibility with T (75.80%) and TMF (76.01%) being greater than B (35.29%) and BMF (36.48%). There was no effect of MF observed on NDF (0.08) digestibility. There were significant effects of Horse (P < 0.01), Period (P < 0.01) and Treatment (P = 0.02) on VDMI. Overall mean VDMI's were 9.63 and 9.39 kg/d for B and BMF, respectively as compared with 12.05 and 12.17 kg/d for T and TMF, respectively. These results indicate that there were no significant differences in DM or nutrient digestibilities for MF-treated horses.