Apresentação

Brazil is one of the last agricultural frontiers in the world and has the largest commercial herd. Our challenge is to increase productivity, since national production indexes are still relatively low, despite of considerable improvement occurred on recent years. The use of new technologies is essential to improve animal productivity of Brazilian beef cattle. One way to increase animal productivity is to improve the nutritional requirements systems, using data produced under tropical conditions, making more efficient activity.

Experiments conducted in Brazil evaluating the nutritional requirements of cattle, in contrast to other countries, are relatively new, and started only in the 70s. Especially, professors José Fernando Coelho da Silva and Celso Boin at Universidade Federal de Viçosa (UFV) and Escola Superior de Agricultura Luiz de Queiroz (ESALQ), respectively, who were the pioneers in this research area in Brazil. Later, other professors/researchers from other institutions started their research in this theme. The first publication on this subject was made at the International Symposium on Nutritional Requirements of Ruminants in October of 1995 in Viçosa, Minas Gerais.

In June of 2006, during the V SIMCORTE, the first edition of Nutritional Requirements of Zebu and Feed Composition system was published, named BR-CORTE. Only data of Zebu cattle was used with a small number of individual data (187 observations).

The second edition of the BR-CORTE was published in June of 2010, during the VII SIMCORTE. This edition included Zebu and their crosses with beef cattle. In this version, the database (752 individual observations) was increased and could be considered reliable.

Subsequently, a software was developed to formulate diets and to calculate the nutritional requirements, named BR-CORTE 1.0, which was made available online on the website www.brcorte.com.br in June of 2012. This software has been updated in 2014, including performance prediction, named BR-CORTE 2.0, also available on the same website. The BR-CORTE 3.0 is a software update, it including the new equations of BR-CORTE 2016 and requirements for pregnant cows. The BR-CORTE 3.0 also includes methane production and nitrogen and phosphorus excretion prediction.

The third edition of Nutrient Requirements of Zebu and Crossbred cattle (BR-CORTE) included four new chapters, using a new and updated database to estimate the nutritional requirements of cattle, being the only system specifically described for Zebu cattle. The committee of this third edition was composed of members from different universities in Brazil: UFV-MG, UFBA-BA, UFLA-MG, UFMG-MG and UESC-BA.