PSXIV-13 - Supplemental essential oil blends plus 25-hydroxy-vitamin-D3 improve carcass characteristics in cattle finished under tropical conditions

A total of 90 young crossbreed bulls (initial weight=228.04±7.06 kg) were used in a 171-day feeding trial in order to evaluate the combination of supplemental blend of essential oils (Crina^® Ruminants; DSM Nutritional Products) plus 25-hydroxy-vitamin-D3 (HyD^®, DSM Nutritional Products; EO+HyD) on growth performance and carcass characteristics in cattle finishing under tropical conditions. Cattle were blocked by weight into 2 blocks and randomly allocated to 2 treatments (9 pens/treatment, 5 bulls/pen). Cattle were fed with a steam-flaked corn-based diets (average diet NEm= 1.95 Mcal/kg during first 84-d, and 2.15 Mcal/kg during the remaining 87-d). Treatments consisted of: 1) EO+HyD supplementation along fattening period (171-d), or 2) supplementation with monensin (Rumensin^®, Elanco Animal Health; 20 mg/kg diet) during the first 84-d and monensin (20 mg/kg diet) plus virginiamycin (Stafac^®, Phibro Animal Health; 20 mg/kg diet) during remaining time (87-d). The average THI during course of the experiment was 76.67±2.7 with a maximum of 85.46±2.2 and minimum of 68.29±2.6. There were no statistical differences (P > 0.10) between EO+HyD and ionophores/antibiotic supplemented cattle on DM intake (7.575 vs 7.534 kg/d), average daily gain (1.433 vs 1.406 kg), or gain-to-feed ratio (0.189 vs 0.187). However, cattle fed with EO+HyD tended (P = 0.07) to have heavier carcass weight in 5.2 kg (304.9 vs 299.7 kg), showed greater LM area (89.89 vs. 82.77 cm², P < 0.01) and greater estimated retail yield (1.6%, P = 0.02) than cattle receiving ionophores/antibiotic mixture. Cattle receiving EO+HyD showed more percentage of carcass classified as Choice (14.28 vs 13.33%) and “Select” (59.52 vs 44.44%) and lower percentage of carcass classified as “Standard” (26.20 vs 42.23%). The combination of a blend of essential oils plus 25-hydroxy-Vit-D₃ (EO+HyD) in finishing phase improve carcass characteristics. Supplemental EO+HyD is a viable alternative to supplemental monensin, or monensin plus virginiamycin used in growing-finishing diets for feedlot cattle.