A digestion trial was conducted to determine dormant, bluestem-range forage intake,
digestion, and protein flow to the small intestine in steers receiving different crude protein (CP)
supplements. Dietary treatments were 1) control: no supplement; 2) low protein supplement
(Low-CP): SBM + grain sorghum supplement containing 13% CP; 3) moderate protein
supplement (Mod-CP): SBM + grain sorghum supplement containing 26% CP; and 4)
dehydrated alfalfa pellets supplement (Dehy): supplement containing 17.5% CP. Forage intake
increased an average of 36% in steers supplemented with Mod-CP and Dehy, compared to the
forage intake of control steers. Forage intake of steers receiving Low-CP supplement was
similar to that of control steers.
Total tract digestion of forage fiber increased 8% when Mod-CP and Dehy supplements
were fed compared to control treatment, whereas Low-CP supplement caused an 11% decrease
in fiber digestion compared to control treatment. Crude protein flowing into the small intestine
was greatest for steers fed the Mod-CP and Dehy supplements. In conclusion, the Dehy
supplement was as effective as the Mod-CP supplement when fed to provide the same amount
of CP per day; however, when a grain-based supplement was fed, increasing the CP
concentration above 20% significantly improved intake and utilization of poor-quality range
forage.
