Our objectives were to determine the effects of replacing corn with glycerin on growth performance, carcass characteristics, ruminal metabolism, and fiber disappearance in beef cattle. In Exp. 1 heifers (initial BW = 242 ± 32 kg) were fed 1 of 3 treatments from d 1 to 85 (growing phase): (1) 0%, (2) 10%, or (3) 20% glycerin (DM basis). From d 86 to 167 (finishing phase), they were fed a common diet. During the growing phase, ADG and G:F decreased (P ≤ 0.01) with increasing glycerin inclusion, but DMI was not different (P = 0.84). During the finishing phase, heifers fed 10% glycerin in the growing phase had increased (P = 0.05) final BW and HCW and the greatest (trend; P = 0.09) marbling scores. Treatment did not affect (P > 0.15) back fat, KPH, YG, or LM area. In Exp. 2 ruminally fistulated steers were fed 3 treatments in a replicated 3 × 3 Latin square: (1) 0%, (2) 8%, and (3) 16% glycerin (DM basis). Increasing dietary glycerin decreased (trend; P = 0.06) DMI. Glycerin inclusion did not affect mean ruminal pH (P = 0.61), 24-h in situ DM (P = 0.38) or NDF disappearance (P = 0.51). There was a glycerin × time interaction (P = 0.05) for acetate concentration. At 3 and 6 h after feeding, acetate was reduced with increasing glycerin. Mean propionate concentration (P = 0.01) increased, whereas mean acetate- to-propionate ratio (P < 0.01) and mean ruminal H2S (linear; P = 0.05) decreased, with increasing glycerin. Fiber digestion was not increased in steers fed increasing glycerin. But, ruminal propionate was increased and marbling was greatest in heifers fed 10% glycerin.
All Science Journal Classification (ASJC) codes
- Food Science
- Animal Science and Zoology