ABSTRACT The objective of this study was to verify the association of improved native grassland and winter and summer pastures on the weaning rate in beef cattle production. Subsequently, we also verified the socioeconomic and productive characteristics related to the adoption of technologies to increase the weaning rate of the farmers. The survey was conducted with 73 producers of Hereford and Braford cattle in the state of Rio Grande do Sul, Brazil. A data analysis was performed using the minimum ordinal squares method and the regression analysis (Tobit). The results showed that cattle farmers who adopt winter pastures have greater weaning rates, and the factors that influence this adoption are related to a greater number of employees on the farm and the use of a crop-livestock production system. In addition, farmers who receive a greater number of technical assistance visits per year are more likely to adopt winter pastures and improved native grassland. This information can be useful in the formulation of technological dissemination programs that aim at a sustainable production of beef cattle.

O Brasil e os EUA estão entre os principais produtores mundiais de carne bovina. Entretanto, distorções no mercado alimentar decorrentes da presença de barreiras comerciais podem comprometer a competitividade desses países. O objetivo deste trabalho foi verificar a competitividade da carne bovina brasileira e norte-americana, no mercado internacional, entre 1990 e 2008. Para isso, foi utilizado o Índice de Competitividade Revelada (CR) para inferir sobre os efeitos que subsídios, acordos comercias e barreiras sanitárias exercem sobre a competitividade da carne bovina dos respectivos países. Os resultados indicaram que o Brasil obteve vantagens competitivas no período de 1991 a 2008, enquanto que os EUA apresentaram vantagens entre 1993 e 2003. Os acordos comerciais elevaram a competitividade dos países envolvidos, contudo ocorreram diminuições dos índices quando problemas sanitários foram identificados. Em suma, os EUA, mesmo com os altos subsídios fornecidos aos produtores rurais, apresentou desempenho inferior em comparação ao Brasil no mercado mundial da carne bovina.

Brazil and the USA are among the leading producers of beef. However, trade barriers can bring about distortions in the food market, compromising competitiveness. The objective of this study was to evaluate the competitiveness of beef from Brazil and the USA in the international market from 1990 to 2008. The Revealed Competitiveness Index was used to discuss the effects of subsidies, trade agreements and sanitary barriers on the competitiveness of beef in the respective countries. The results indicate that Brazil had competitive advantages in the period 1991 to 2008, while The USA had advantages in the period 1993 to 2003. Trade agreements increased the competitiveness of these countries, however there was decrease in rates when sanitary problems were identified. Therefore, even with high subsidies provided to farmers, the USA presented lower performance compared to Brazil in the beef world market.