PSII-B-14 - Combination of Essential Oils, α-amylase and 25-hydroxy-vitamin-d3 Increases Performance by Feedlot Cattle on Adaptation Period

Abstract: Concerns about the use of in animal feed antibiotics are growing. It is, therefore necessary to develop alternative products that can replace antimicrobial feed additives. Thus, our objective was to evaluate the effects of associating feed additives on feedlot performance of Nellore bulls. Nellore bulls (n= 160; iBW, 380± 5.8 kg; age, 18 mo) were allocated in 20 pens (n=8/pen), in a completely randomized block design, according to the treatments: 1) MON+VM - Sodium Monensin (MON, 25 mg/kg DM, Elanco Animal Health, Indianapolis, IN), + Virginiamycin (VM, 30 mg/kg DM, Phibro Animal Health Corporation, Guarulhos, São Paulo), and 2) CRD - Crina RumistarTM + HyD, a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25-hydroxy-vitamin-D3 at 1 mg/animal/day (DSM Nutritional Products, Basel, Switzerland). The initial BW was utilized as a criterion for block formation. Pens were considered experimental units (10 pens per treatment). Animals were adapted to the diets during 14 days with gradually increasing concentrate level from 70% to 86% of diet DM, and fed for 90 days. Weight assessments were performed at day 0 and 28 discounted by 4% from the full BW as ruminal fill. Data were analyzed using PROC MIXED of SAS and means were separated using the PDIFF statement, adopting P< 0.05. Feeding CRD increased the DMI (10.54 kg vs. 8.74 kg, P< .0001), ADG (2.00 vs. 1.59 kg/d, P< .0001) and final BW (430 vs. 418 kg, P< .0001) compared with animals fed MON+VM. The fluctuation in dry matter intake (4.55, P=0.24) and G:F (0.186, P=0.15) were similar among treatments. Therefore, the inclusion of Crina RumistarTM +HyD can be used as a tool to increase performance of feedlot adaptation period.