Productive Performance of Broiler Chickens Sheltered at Two High Density Levels in Hangars Provided with Different Positive Ventilation Systems

Abstract

The Brazilian fowl growing reached a prominent place among the agro industry activities in the country. Nowadays, Brazil is the largest broiler exporter of the world. In tropical and subtropical climates, however, the high values in both temperature and air relative humidity, specially in summer, associated to the typical facility type without thermal isolation, rather endanger the productive performance of the Brazilian stocks and is one of the main factors that negatively affect this activity. Because of these conditions, it is necessary to project thermal cooling systems that would be compatible with Brazilian reality. The positive ventilation associated with cooling by evaporative means has been one of the most suitable options. Thus, this study was carried out in order to evaluate the effects of two positive ventilation systems (tunnel and lateral) associated with internal spraying and covering sprinkle upon the productive performance of broiler chickens sheltered at two high density levels (16 and 18 chickens/m2). The experimental phase was carried out in commercial hangar for broiler chickens in Minas Gerais State, under summer conditions. The evaluations of the fowl's productive performance were weekly performed, and based one weight gains, food conversion, ration consumption, mortality and alive weight. Based on the productive performance, it was concluded that no statistical differences occurred (P>0.05) between the ventilation systems and shelter densities under evaluation. The growing of broiler chickens with birds/m² made possible an average production increment of 12.5%, relative to that obtained at the density of 16 birds/m², without endangering the productive performance of the stock.