INFLUENCE OF HIGH-STARCH VS HIGH-FIBER ENERGY SUPPLEMENTS ON PERFORMANCE OF STOCKER CATTLE GRAZING WHEAT PASTURE AND SUBSEQUENT FEEDLOT PERFORMANCE

A 3-yr study was conducted to determine effects of high-starch (HS) or high-fiber (HF) energy supplements on performance of fall-weaned stee r calves (n = 192, Exp. 1 and 2; n = 84, Exp. 3) grazing winter wheat pasture (Triticum aestivum variety 2157) and subsequent feedlot perfor mance. The steers received 1) no supplement (CL) other than free-choic e access to a commercial mineral mixture or 2) were hand-fed 6 d/wk ei ther a corn-based HS supplement, or 3) a soybean hull/wheat middling-b ased HF supplement. In Exp. 1 (1989-1990), a fourth treatment provided ad libitum access to the HF supplement (SFHF). Supplements contained 88 mg of monensin/kg and the combination of ionophore, minerals and sa lt (8%) was used to limit intake of the SFHF supplement. Target level of daily consumption of all supplements was .75% of mean BW. Stocking density was increased by 33% (i.e., from 1.24 to 1.65 steers/ha) in Ex p. 1 and 3, and by 22 to 44% in Exp. 2 when supplements were fed. Subs equent to grazing wheat pasture in Exp. 2 and 3, feedlot performance a nd carcass quality (Exp. 2 only) of the cattle were measured. Over the 3-yr period (pooled analysis), mean daily supplement consumption was .65% BW. Daily gains were increased (P < .001) .15 kg by supplementati on and were .92, 1.06, and 1.08 kg for CL, HS, and HF, respectively. D aily gains were not influenced (P > .45) by type of energy supplement. Mean supplement conversions (kilograms as-fed kilogram of increased g ain(-1).hectare(-1)) were 5.4 for HS and 5.0 for HF and did not differ (P > .95). Subsequent feedlot daily gain was decreased .09 kg(P < .05 ) by supplementation in Exp. 2 but not in Exp. 3 (P > .80). This suppl ementation program for growing cattle on wheat pasture allowed stockin g density to be increased by approximately one-third and increased dai ly gains by .15 kg.