399 The 25-hydroxyvitamin D3 supplementation improves animal performance of Nellore cattle grazed in tropical grass

Abstract

Abstract The objective was to evaluate the effects of 25-hydroxyvitamin D3 (HyD®) supplementation on performance and carcass characteristics of grazing Nellore beef cattle. Eighty finishing Nellore bulls were equally distributed according initial BW (437 ± 4.93 kg) in ten Brachiaria brizantha cv. Xaraés paddocks (8 bulls per paddock) using a randomized complete block design with five replicates (paddocks) per treatment. Experiment was conducted in two phases during dry season, from August to November 2017. Phase 1 consisted in all animals receiving the same basal concentrate for 33 days. In phase 2, animals received the treatments for the following 63 days: 1) Control (basal concentrate, no HyD®) or 2) HyD (basal concentrate + 1mg of HyD®/bull/day). The basal concentrate (18% CP and 80% TDN) was formulated to have 82.0% ground corn, 12.0% soybean meal and 6.0% mineral-vitamin supplement (as % DM), being daily offered to bulls at 7.0 kg/animal/day in collective feeders located at each paddock. Final BW (FBW) and average daily gain (ADG) were evaluated for phase 1, 2 and total period, while supplement intake, hot carcass weight (HCW) and dressing percentage was evaluated for total period only. Mineral-vitamin supplement and HyD® were provided by DSM Nutritional Products. Data were analyzed using the MIXED procedure of SAS® 9.3, with each paddock considered one experimental unit and values declared significant when P < 0.10. There was no treatment effect on phase 1 in FBW and ADG, as expected. In phase 2, treatment effects were observed for HyD in FBW (562.75 vs. 568.70; P = 0.094) and ADG (1.350 vs. 1.437 kg/day; P = 0.029) over the control group, respectively. Moreover, the total period ADG was greater for HyD treatment (1.311 vs. 1.375; P = 0.095). No effects were observed in carcass characteristics and concentrate intake. In conclusion, HyD® improves animal performance of Nellore beef cattle grazed in tropical conditions.