PSX-A-6 - Energy and Nutrient Digestibility in Hybrid Rye Ground to Two Particle Sizes and Fed Without or with Multicarbohydrase Supplementation to Growing Pigs

Abstract: Newly breeded hybrid fall rye (HFR) with improved ergot resistance can be an alternative energy source for pigs. Sixteen ileal-cannulated barrows (initial BW = 18.2 ± 1.0 kg) were used to determine the effects of particle size (PS) and multicarbohydrase (MC) supplementation on energy and nutrient digestibility in HFR. Pigs were randomly assigned to 1 of 8 diets in a replicated 8 × 3 incomplete Latin square design. Each period lasted 9 d, with the first 5 d being for adaptation followed by 2 d each for fecal and ileal digesta collection. Two HFR varieties (KWS Bono and KWS Gatano) were hammer milled to a coarse (1,111 μm and 1,210 μm) or fine (594 μm and 717 μm) PS. Diets contained 92.9% HFR as the only source of protein without or with MC supplementation and 0.3% titanium dioxide as an indigestible marker. Data were analyzed using the MIXED procedure of SAS, with the final model having variety, PS, MC supplementation, and their interactions as the main effects. There were no interaction effects of variety, PS, and MC supplementation on the variables measured. The apparent total tract digestibility (ATTD) of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) were greater (P < 0.05) in KWS Bono than in KWS Gatano. The ATTD of gross energy (GE) and NDF tended to be greater (P < 0.10) in finely than in coarsely ground HFR. MC supplementation increased (P < 0.05) the ATTD of DM (83.5 vs. 84.6%) and GE (83.1 vs. 84.2%) and tended to increase (P < 0.10) the ATTD of NDF in HFR. In conclusion, the nutrient digestibility of HFR can be affected by its variety, and fine PS and MC supplementation could improve the nutrient digestibility in HFR fed to growing pigs.