PSIII-2 - Effects of hand-fed versus self-fed supplementation on stocker steer growth, performance, and forage production on smooth bromegrass pastures

Abstract: eed products and additives are available in a multitude of options to increase performance, animal health, and efficiency of cattle while also fitting the individual needs of producers.  A variety of options are used to meet the broad range of management situations, including self-feeding, daily delivery and liquid delivery. The objective of this study was to determine steer performance based on supplementation time, method, and addition of ionophores while grazing smooth bromegrass pastures. Steers (n=80 head; 265 kg ± 5 kg) were randomly assigned to one of 20 smooth bromegrass pastures to graze from late May to late September (121 d). Treatments (n = 4 pastures/treatment) evaluated included positive control (MIN, free-choice mineral); self-fed supplements of protein blocks with ionophore (BLOCKRU) or without ionophore (BLOCK); and hand-fed supplements of 50% corn: 50% dried distillers with ionophore (HANDRU) or without ionophore (HAND). Steers in the hand-fed treatments were fed 3x per week to provide 0.25% of BW on DM basis daily of feed.  Steers were weighed individually every 28 d to determine gain differences and adjust feeding rates. Weekly, self-fed supplements were weighed to determine average weekly intake. Pasture biomass and nutrient composition were measured and analyzed monthly. Prior to placement in feedlot, steers were measured by ultrasound for carcass composition. Data was analyzed with PROC GLIMMIX with pasture as experimental unit and animal within pasture as subsamples and included pre-planned contrasts. Steers that were hand-fed had greater ADG and were heavier at the end of the grazing period as compared with self-fed supplementation (P = 0.01).  There was no difference in ADG, total gain, or final weight based on addition or not of an ionophore (P > 0.37). Hand-fed steers tended (P = 0.07) to have greater gains and final weight as compared to mineral only steers. There was no difference in gains between steers that were self-fed protein blocks as compared to MIN (P =0.78).  The gain advantages for handfeeding were observed by 84 d of grazing (P = 0.03). Steers that were supplemented tended to have greater muscle depth than MIN (P = 0.07) while there were no differences in marbling scores (P > 0.27) nor backfat thickness (P > 0.52) between any comparisons. There was no difference in available biomass between treatment groups (P > 0.50). Hand feeding supplements to cattle resulted in greater performance as compared to self-fed feeds evaluated. Based on 2024 costs of production and assuming a 20-mile delivery to feed cattle, the lowest cost of gain was for mineral only followed by hand-fed supplements with the most expensive being protein blocks.