Strategies for the supplementation of dairy cows in the Brazilian semi-arid

The Brazilian semi-arid region has 928 km(2) ranging from the northern portion of Minas Gerais and Espirito Santo States, the semi-arid lands of Bahia, Sergipe, Alagoas, Pernambuco, Paraiba, Rio Grande do Norte, Ceara, and Piaui States, and 45 counties from southeastern Maranhao State. Population is mainly concentrated in rural areas and the major occupation is agriculture and livestock production. Dairy production is one of the few options in these areas, mainly in northeast Brazil, where the feeding systems are based on cultivated forage crops and use of native vegetation, predominately the "Caatinga". These aspects give seasonal characteristics for the production on this region. Inadequate amount and distribution of rainfall in this region presenting strong spatial and seasonal variability and prolonged dry periods practically determines the need for supplementation feeding for dairy cows for production systems located in the semi-arid region. Thus, supplementation has been based on the use of forage resources adapted to the drought, by-products, residues from local agro-industry, and on concentrate feeding. Farmers are also using different options trying to reduce costs without losing productivity during the dry periods. Production systems such as "CBL" (Caatinga-Buffel Grass-Leucaena) and "Gloria System" have been proposed aiming to alleviate the adversities. In addition to these systems, the utilization of agro industrial by-products, crop residues, and native forage resources are important options. In this aspect, the forage cactus (Opuntia ficus-indica Mill.) deserves special attention for its great adaptation, nutritive value, and productivity in the region.