| Three experiments were conducted to evaluate the effect of supplementing dried distillers grain (DDG) to cattle fed bermudagrass round bale silage (RBS) on performance, reproduction, intake, digestibility, and rumen parameters. In Experiment 1 Angus (n = 30) and Brangus (n = 30) heifers were supplemented with: 1) DDG at 0.75% BW; 2) DDG at 0.75% BW + soybean meal (SBM) at 7.5% of DDG; or 3) DDG at 0.75% BW + SBM at 15% of DDG. No treatment (P > 0.05) effects were observed for BW, BCS, ADG, or hip height. Treatments were similar (P> 0.05) for REA, REA/cwt, IMF, RIBFT, and RMPFT. Mean NEFA, PUN, and glucose concentrations were similar (P> 0.05) between treatments. There were no treatment effects (P> 0.05) on pubertal status and reproductive responses associated with breeding.;In Experiment 2 and 3 Angus (n = 4) and Brangus (n = 4) steers were utilized and received RBS only on d -2 and -1, d 0, 1.13 kg of DDG, d 4, 2.26 kg of DDG, d 8, 3.39 kg of DDG, and d 12, 4.52 kg until d 15. As DDG intake increased, dry matter intake (DMI) of RBS was not affected (P> 0.05), total DMI increased (P≤ 0.05), and ruminal pH decreased (P≤ 0.05). Steers consuming 3.39 and 4.52 kg DDG, had increased (P≤ 0.05) NH3-N. Level of DDG affected PUN (P≤ 0.05) and tended (P≤ 0.09) to effect NEFA and glucose concentrations.;Experiment 3, a Latin square design, all steers received RBS and were assigned to: 1) RBS only; 2) DDG supplement at 0.33% BW; 3) DDG supplement at 0.66% BW; or, 4) DDG supplement at 1% BW. There was a quadratic ( P≤ 0.05) response to the amount of DDG supplemented on RBS DMI, total DMI intake, and total tract apparent DM digestibility and a linear ( P< 0.01) response of fecal output. Mean pH had an inverse linear relationship (P= 0.02) with amount of DDG and a cubic response (P< 0.01) for NH3-N concentrations.;In conclusion, addition of SBM had no effect on heifer growth or reproductive performance, and increasing levels of DDG increased total DMI, digestibility, fecal output, and altered rumen parameters. |
