| Popis: |
This study evaluated the effects of Sweet Bran™ (SB) and/or wet distillers grains with solubles (WDGS) in the diet alone or in combination on performance, carcass characteristics, ruminal pH, and rumination of finishing beef cattle. Steers (n = 455) were randomly allocated to 48 pens and assigned to 1 of 4 steam-flaked corn-based dietary treatments containing: no byproducts (CON), 20% WDGS (WDGS), 20% SB (SB), or 20% SB and 10% WDGS (COMBO). Within each pen, 2 steers were randomly selected to receive a ruminal pH bolus and ear tag to quantify pH and rumination. Diet samples were collected weekly to determine particle size and physically effective fiber. Final BW, DMI, and ADG were greater (P < 0.01) for WDGS, SB, and COMBO than CON. Hot carcass weight was greatest (P = 0.04) for WDGS and SB, intermediate for COMBO, and least for CON. Yield grade tended (P = 0.09) to be greater for WDGS, SB, and COMBO than CON. A numerical increase in abscessed livers was observed for CON. The percentage of particles > 4 mm was greatest (P < 0.01) for CON, intermediate for SB, and least for WDGS and COMBO. However, NDF (P < 0.01) and peNDF (P < 0.01) were greatest for COMBO, intermediate for WDGS and SB, and least for CON. A treatment × time interaction was observed as CON cattle spent less time ruminating at 0800 and 1000 h (P < 0.01) in a 24h period. Ruminal pH was least (P < 0.01) for CON from 0800 to 1800 h. Addition of WDGS and/or SB improved performance and reduced feed cost of gain when incorporated into steam-flaked corn-based finishing diets. Relationships between peNDF, rumination behavior, and ruminal pH suggest that SB and/or WDGS enhance buffering capacity when steam-flaked corn is replaced in the diet. |
