1471 Effect of corn wet distillers' grains inclusion in growing diets on backgrounded cattle performance

Abstract

Distillers' grains (DG) can be used as energy as well as protein dietary sources. An experiment was conducted to evaluate the effect of partially replacing dry-rolled corn (DRC) and sunflower meal (SFM) with corn wet DG (WDG) in growing diets on cattle performance. One hundred ninety-two Angus calves (199 ± 3 kg initial BW) were assigned by weight to 1 of 3 blocks and group housed in 1 of 24 pens. Pens were randomly assigned to 1 of 4 diets containing (DM basis) 0% WDG, 19.4% DRC, and 20.4% SFM (CON); 10.0% WDG, 13.9% DRC, and 15.9% SFM (10-DG); 20.0% WDG, 8.0% DRC, and 11.8% SFM (20-DG); or 35.0% WDG, 0% DRC, and 4.8% SFM (35-DG). All diets contained 58.2% sorghum-sudangrass silage and 2.0% dry supplement. Diets were formulated to generate a RDP balance equal to zero and to meet or exceed MP requirements at expected ad libitum DMI and ADG. Dietary CP and lipid concentrations and IVDMD measured 12.0, 2.97, and 66.3%; 13.5, 4.00, and 66.8%; 15.1, 5.04, and 67.3%; and 17.3, 6.61, and 68.2% for CON, 10-DG, 20-DG, and 35-DG, respectively. Calves were fed once daily for 85 d and held off feed for 16 h to record initial and final individual BW. Data were analyzed as a generalized randomized complete block design. Cattle ADG was greater (P < 0.01) for calves fed the 20-DG diet (913 ± 20 g) compared with those fed the CON (682 ± 20 g) or 10-DG (829 ± 20 g) diets, although it was similar (P = 0.93) to those fed the 35-DG (915 ± 20 g) diet. Conversely, DMI was similar (P > 0.65) between cattle fed the CON (6.01 ± 0.27 kg/d), 10-DG (5.97 ± 0.27 kg/d), and 20-DG (5.93 kg/d) diets and smaller (P < 0.01) compared with cattle fed the 35-DG (5.41 ± 0.27 kg/d) diet. Consequently, G:F improved (P < 0.01) with increasing WDG dietary inclusion (114.4, 139.5, 154.2, and 169.6 ± 6.7 for CON, 10-DG, 20-DG, and 35-DG, respectively). Greatest lipid concentration in the 35-DG diet may have decreased fiber digestibility, which, in turn, could relate to reduced DMI. Additionally, ADG quadratic response (P < 0.01) may have resulted from greater NEg concentration and from DMI quadratic response (P < 0.01) with increasing WDG dietary inclusion. Including 35% WDG in a silage-based diet resulted in greatest G:F and growing-according ADG.