Combined use of monensin and virginiamycin in high-concentrate diets and its effects on feeding behavior, particle sorting and dry matter intake fluctuation of feedlot Nellore cattle

• Grant number: 18/07580-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2018
• End date: September 30, 2019
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Breno Leite Demartini
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Associated scholarship(s): 18/20653-2 - Role of undigestible NDF towards meeting the forage requirement, BE.EP.IC

Abstract

This study will evaluate the effect of a diet containing a higher proportion of concentrate at the finishing period supplemented with different combinations of sodium monensin (MON) and virginiamycin (VM) on feeding behavior, dry matter intake variation and particle sorting of Nellore cattle. One hundred and twenty Nellore yearling bulls will be used, with initial body weight of 370 kg. The study will last for 112 days, being 14 days of adaptation period (66% to 78% of concentrate), 70 days of finishing period 1 (84% of concentrate) and 28 days of finishing period 2 (88% of concentrate). The yearling bulls will be assigned to the following treatments: 1) MON (30mg/kg) for the entire feeding period, 2) VM (25 mg/kg) for the entire feeding period, 3) VM (25 mg/kg) + MON (30 mg/kg) during the period of 14 days of adaptation and only VM (25 mg/kg) in the entire finishing period, 4) VM (25 mg/kg) + MON (30 mg/kg) for the entire feeding period, and 5) VM (25 mg/kg) + MON (30 mg/kg) during the adaptation period and finishing period 1 and only VM (25 mg/kg) during the finishing period 2. The yearling bulls will be subject to visual behavior on the day 60 (finishing 1) and 105 (finishing 2). Samples of diet and the refusals will be collected from each pen on the day of behavior and in the next day, respectively, to determine the extent of the particle sorting. For measurement of DMI variation, the difference on intake between two consecutive days will be measured throughout the experimental period. (AU)