Effects of increasing soybean hulls in finishing diets with wet or modified distillers grains plus solubles on performance and carcass characteristics of beef steers

Abstract

Two experiments evaluated feeding soybean hulls (SBH) in finishing diets that contain distillers grains plus solubles on performance and carcass characteristics. Dietary concentrations of SBH were 0, 12.5, 25, and 37.5% of diet DM. In Exp. 1, 167 crossbred yearling steers (395 ± 22 kg of BW) were fed for 117 d in a randomized block design in which pelleted SBH replaced dry-rolled corn. All diets contained 25% modified distillers grains plus solubles, 15% corn silage, and 5% liquid supplement. As SBH concentration increased, DMI decreased linearly (P = 0.04). Gain and G:F decreased linearly (P < 0.01) in response to increasing concentrations of SBH, which decreased relative energy value from 91 to 79% of corn. Hot carcass weight linearly decreased (P < 0.01) by 24 kg as SBH increased. In Exp. 2, a randomized block design used 160 backgrounded steer calves (363 ± 16 kg of BW) in a 138-d finishing study with 0, 12.5, 25, or 37.5% SBH in the meal form. Basal ingredients consisted of a 1:1 ratio of high-moisture corn and dry-rolled corn, 40% wet distillers grains plus solubles, 8% sorghum silage, and 4% dry meal supplement. There was a tendency (P = 0.12) for a quadratic increase in ADG and G:F as dietary SBH increased, with numerically greatest ADG and G:F with 12.5% SBH. Feeding 12.5 to 25% SBH with 40% wet distillers grains plus solubles (Exp. 2) had little effect on performance but decreased ADG and G:F in diets with 25% modified distillers grains plus solubles (Exp. 1).