On-line version ISSN 1678-992X
MIRAGLIOTTA, Miwa Yamamoto; NAAS, Irenilza de Alencar; MANZIONE, Rodrigo Lilla and NASCIMENTO, Fernando Ferraz do. Spatial analysis of stress conditions inside broiler house under tunnel ventilation. Sci. agric. (Piracicaba, Braz.) [online]. 2006, vol.63, n.5, pp. 426-432. ISSN 1678-992X. http://dx.doi.org/10.1590/S0103-90162006000500002.
Broiler building typology associated with the local characteristics (climate, topography and surrounding vegetation) and handling systems (stocking density, curtains, equipment and nutrition) influence the inside environment. A spatial distribution analysis of these conditions may indicate stress zones in the house. The aim of this research was to apply spatial analysis of thermal, aerial and acoustic environmental conditions inside a tunnel ventilated broiler housing, with a stocking density of 18 birds m-2. This study was carried out in Rio Claro, SP, Brazil, in a 12 m × 115 m house divided into three equal sections (East, center and West), East-West oriented, and virtually divided on 132 cells, each one measuring 3.0 m × 3.5 m. At the geometric center of each cell the following variables were monitored: dry bulb temperature, relative humidity, air velocity, noise level and light intensity. Average broiler mortality was recorded in each of the three sections. Data collection was made systematically from West to East, opposite to the air flow produced by the tunnel ventilation system, during the warmest period of the day. Measurements took place during the sixth week of production. A geostatistics software tool was used to build spatial distribution maps of the recorded variables in order to infer intermediate stress conditions. It was concluded that the stress zones were located at both ends of the house and the highest mortality index was found at the West sector where the exhaust fans were placed.
Keywords : broiler production; environment; geostatistics; heat stress; spatial distribution.