Effects of Dried Distillers Grains + Condensed Distillers Soluble Supplements (Sweetpro® Products) on Measures of Growth and Apparent Diet Digestibility in Forage-fed Yearling Beef Calves

Four experiments were conducted to evaluate the effects of dried distillers grains + condensed distillers solubles (DDG+CDS) supplements on measures of performance of beef heifers, and apparent dry matter (DM), neutral detergent fiber (NDF), and crude protein (CP) digestibility of beef steers. In Exp. 1, heifers supplemented with DDG+CDS blocks (SweetPro; SP) for 42 d had lesser free-choice supplement DM intake (DMI) and average daily gain (ADG) compared to heifers offered 6 lb/d of a molasses / cottonseed meal slurry (80:20; as-fed). In Exp. 2, ADG did not differ (P = 0.87) among individually-fed, heifers supplemented for 42 d in drylot with a citrus pulp (CT) or dry distillers grain-based (DDG) supplement, but both were greater (P ≤ 0.01) than heifers offered SP supplement, a result of reduced voluntary intake of SweetPro. However, ADG did not differ (P = 0.16) among heifers concurrently offered the same supplements while grazing bahiagrass pastures over the same 42-d period. After combining heifers from drylot and pasture for an additional 42-d evaluation on bahiagrass pastures, ADG of heifers fed DDG and CT was similar (P = 0.25), but again greater (P ≤ 0.04) than heifers fed SP supplement. In addition, SP and CT heifers had similar (P = 0.71), but greater (P ≤ 0.06) pregnancy rates than DDG heifers. In Exp. 3, steers individually fed DDG or DDG+CDS in a loose meal form (Fresh Start; FS) had similar (P ≥ 0.67) hay DMI, and apparent DM and NDF digestibility, but less (P ≥ 0.001) CP digestibility. In Exp. 4, heifers pair-fed SP or CT supplements for 42 d had similar (P ≥ 0.25) supplement DMI and ADG. In summary, SweetPro supplementation resulted in less ADG of developing beef heifers compared to commodity-based supplements of similar energy and protein composition. This response is due to a lesser voluntary intake of SweetPro supplement. When pair-fed to control intake among SweetPro and a commodity based supplement, no differences in performance were realized. When provided in a loose meal form (Fresh Start), a reduction in apparent digestibility of CP was realized in growing steers fed a forage-based diet.