131 Evaluating Supplementation Programs for Growing Calves Grazing Bermudagrass Pastures

Abstract

Abstract Due to factors such as, high delivery costs, supplement availability, and labor; producers are interested in supplement delivery alternatives. Our objective was to determine gain in response to hand-fed (HF) or self-fed (SF) summer supplementation programs at the University of Arkansas Livestock and Forestry Research Station, on 20, 0.81-ha common bermudagrass pastures at a stocking rate of 5 growing calves per pasture (BW ± SD = 247 ± 24.6) over three years. This was a 2 x 2 + factorial arrangement of treatments, which included: Control (CON) – only free choice mineral; HF 1.13 kg/d by-product-based supplement offered only late summer (LS) or all summer (AS); SF tub supplement (PVM Cattle Tub, Positive Feed Ltd., Sealy, TX) either LS or AS. The HF supplement in year was a 50:50 blend of soybean hulls and corn gluten feed, in year 2 an extruded dried distillers grains cube (MasterHand Milling, Lexington NE) was used for HF, while in year 3 corn gluten feed was the HF supplement. Data were analyzed as a generalized randomized complete block design using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC). Fixed effects in the model included supplementation treatment, year, and year by treatment interaction. Even though different HF supplements were used each year there was no year X treatment interactions (P ≥ 0.10); therefore, results are presented pooled across years. Early summer ADG was greater for HFAS (P < 0.01) than CON and SFAS, while supplemental efficiency (SE, kg added gain/kg supplement) in early summer was less (P = 0.05) SFAS than HFAS. Late summer ADG was greater for HF than SF and CON; while SE did not differ (P = 0.52) among treatments. Total supplement costs, in US dollars per steer for SF, were $67.50 when fed AS and $49.36 when fed in late summer only. Supplement costs for HF were much lower, $33.54 and $15.72/steer for AS and LS, respectively. Cost of added gain for SF was $28.33 and $16.14/kg for SFAS and SFLS, respectively. When providing supplement by HF, cost of added gain was $3.32 and $1.68/kg for HFAS and HFLS, respectively. With these results, we determined the most cost-effective way to add gain with supplement to growing calves grazing bermudagrass pasture is to hand-feed. When calves were HFAS, total supplement costs were higher, but considering the greater ADG, ending bodyweight, and supplemental efficiency ratio, HF supplements should provide a positive net return. Calves on this experiment did not respond as expected to the SF supplement, likely because the bermudagrass pastures in this experiment averaged over3% CP and were in excess of 10% even in the LS sampling periods.