Modeling and mapping of thermal environment to evaluate the performance of broiler chickens lodged in acclimatized housing / Modelagem e zoneamento do ambiente tÃrmico para avaliar o desempenho de frangos de corte criados em galpÃes climatizados

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objective of this work was to develop and validate a mathematical and computational model to predict thermal environment (air temperature, relative humidity, temperature-humidity index â THI and environmental index for broiler chickens productivity â EPIbc), main physiological responses (skin temperature â TS, rectal temperature â TR and respiratory frequency â RF) and productive performance (daily feed intake â DFI, daily weight gain â DWG and feed conversion â FC) of broiler chickens lodged in acclimatized housings, equipped with negative pressure tunnel ventilation system (TVS) associated with evaporative cooling systems â ECSs (pad cooling or misting system or both of them). The computational model was used to study the ECSs potential use in Southeastern region of Brazil. Experimental results, used to validate the model, showed that standard errors between simulated and measured values were smaller than or equal to 1.27, except for relative humidity, DFI and RF that were 5.43%, 1.77 g day-1 and 2.15 breathes min-1, respectively. The proposed mathematical model simulated satisfactorily all response variables modeled; then, software named SisTÃnel was developed as a tool for presenting results by table and graphics, permitting the simulation and study of several productionsâ scenarios. Mathematical and computational models and meteorological data from 1980 to 2001 available at Project Reanalysis-2 (NCEP/NCAR) were used to map the potential of use of ECSs, with different efficiencies, coupled to TVS for broiler chicken grown at Southeastern of Brazil. Thermal environment was characterized by temperature-humidity index (THI) and chicken performance was determined by DFI, DWG and FC. Simulations involved four systems configurations (treatments): a) TVS (control), b) TVS associated with pad cooling with 40% efficiency (TVSPAD40), c) TVS associated with pad cooling system with 70% efficiency (TVSPAD70) and d) TVSPAD70 associated with a misting system (TVSPAD70+MIST). Results showed that ECS use effect compared to TVS was beneficial, allowing to conclude that, especially during September and October, TVSPAD70+MIST provided the best production condition for almost all Southeastern region, standing out North and Northwest areas of Minas Gerais State.

ASSUNTO(S)

avicultura thermal comfort resfriamento evaporativo simulation tunnel ventilation simulaÃÃo conforto tÃrmico evaporative cooling ventilaÃÃo tÃnel poultry engenharia agricola

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