Environmental and productive impact of the process of intensification of the of growth and finishing phase of beef cattle managed in marandu grass

• Grant number: 18/26492-0
• Support type: Scholarships in Brazil - Master
• Effective date (Start): May 01, 2019
• Effective date (End): February 28, 2021
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Euclides Braga Malheiros
• Grantee: Laís de Oliveira Lima
• Home Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The environmental impact of livestock production is a major challenge to be addressed. This study aims to identify the environmental impact generated through the intensification process of beef cattle production systems. In addition, environmental benchmarks indicators will be created in order to guide more sustainable production systems. The experimental area is composed of 24 ha pastures of Brachiaria brizantha Hochst ex A. Rich Stapf cv. Marandu which is divided into 12 paddocks of approximately 2 ha each. Forty-eight Nellore steers will be used as testers (n=4/paddock) and additional steers will be utilized in order to maintain the sward height at 25cm. The treatments will be three different levels of intensification: Low (0 kg of N/ha), Medium (75 kg of N/ha) and High (150 kg of N/ha). The experimental will have a randomized block design with four repetitions (i.e. blocks) of each treatment. Nitrogen will be applied as ammonium nitrate. Steers from all treatments will be offered ad libitum loose lick mineral supplementation during backgrounding. During the fattening phase, steers raised on the Low treatment group will remain in the paddock and supplemented at 2% of Liveweight while steers from groups Medium and High will be moved into a feedlot. Forage mass as well as chemical composition will be measured. Animals measure will be intake, digestibility, enteric methane balance, N, liveweight gain, carcass dressing percentage as well as protein and energy deposition.