Efficiency of nitrogen utilization depending on nitrogen fertilization and supplementation in the rearing of beef steers finished on pasture or feedlot

• Grant number: 14/09651-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2014
• End date: March 31, 2016
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Ricardo Andrade Reis
• Grantee: Wilton Ladeira da Silva
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The project aim is firstly to evaluate the efficiency of nitrogen use in cattle production system in marandu grass depending on nitrogen levels and different supplementation strategies on productive, environmental and economical aspects. The project will last two years and will be divided into two experiments concurrently. In the first experiment, the treatments will consist of four levels of nitrogen fertilizer applied in the pastures (0, 90, 180 and 270 kg ha-1 year-1). In the second experiment the treatments will consist of four supplements to the animals in grazing (mineral mix, energy supplementation using corn meal, energy supplementation using corn meal + ±-amylase and corn silage moisture). Evaluations will be conducted in the rearing of animals in the pastures during the rainy season, and in the finishing phase (dry season) in pastures and/or feedlot. Aspects related to the soil as root decomposition and litter nitrogen loss through volatilization of ammonia and nitrous oxide and methane emission will be evaluated. Referring to the pastures, the mass and herbage accumulation, nutritive value, the apparent recovery and efficiency of nitrogen utilization will be evaluated. Concerning animals will be evaluated intake and digestibility nutrients, enteric methane and nutritional and ruminal parameters, performance and carcass characteristics. Finally, the economic viability of cattle production systems recreated in pasture and finished on pasture and/or feedlot in terms of management strategies will be evaluated. (AU)