Spatial variability of air dry bulb temperature and black globe humidity index in a broiler house during the heating phase

Abstract

The air dry-bulb temperature (t db),as well as the black globe humidity index (BGHI), exert great influence on the development of broiler chickens during their heating phase. Therefore, the aim of this study was to analyze the structure and the magnitude of the t db and BGHI spatial variability, using geostatistics tools such as semivariogram analysis and also producing kriging maps. The experiment was conducted in the west mesoregion of the states of Minas Gerais in 2010, in a commercial broiler house with heating system consisting of two furnaces that heat the air indirectly, in the firsts 14 days of the birds' life. The data were registered at intervals of five minutes in the period from 8 a.m. to 10 a.m. The variables were evaluated by variograms fitted by residual maximum likelihood (REML) testing the Spherical and Exponential models. Kriging maps were generated based on the best model used to fit the variogram. It was possible to characterize the variability of the t db and BGHI, which allowed observing the spatial dependence by using geostatistics techniques. In addition, the use of geostatistics and distribution maps made possible to identify problems in the heating system in regions inside the broiler house that may harm the development of chicks.

Spatial variability of enthalpy in rabbit house with and without ridge vent

“…The mathematical model used to perform the semivariogram fitting was spherical, which is widely used in geostatistical studies, since they are referenced in geostatistics as transitive models (models with sill C 0 + C 1 ). The selection of the spherical model is justified because it is the one that best adapted to the fits in studies in the environmental variables in facilities for animals (Ponciano et al, 2013;Gonçalves et al, 2016;Ribeiro et al, 2016). From the fit of a mathematical model to the calculated values of γ (h), the following coefficients of the theoretical model for the semivariogram are calculated: nugget effect (C 0 ), sill (C 0 + C 1 ) and range (a).…”

Spacial Illuminances Variability and Energy Consumption in Aviaries for Laying Hens Equiped With Compact Fluorescent Lamps and Light Emitting Diode

“…To analyse the spatial illuminance dependence degree, it was used the classification of CAMBARDELLA et al (1994), that were considered strong spatial dependence the semivariograms in relation the nugget effect (C0) / (C0 + C1) smaller than the 25% of the sill, moderate between 25 and 75% and weak bigger than 75%. This methodology has been used by several authors (MORRIL, 2014;PONCIANO et al, 2013;CARVALHO et al, 2012;PEREIRA et al, 2012;YANAGI et al, 2011).…”

“…Thus, it is possible to obtain maps to understand the spatial distribution aiding in the planning and lighting control (YANAGI et al, 2011;MORRIL, 2014). This methodology has been used to characterize the environmental data variability in poultry houses, allowing the observation of the spatial dependency, and i dentifying potential flaws within the systems (YANAGI et al, 2011;CARVALHO et al, 2012;PONCIANO et al, 2013).…”

Geostatistics applied to swine facilities equipped with evaporative cooling system

“…By using evaporative cooling system, environment thermal conditions may improve (Ponciano et al, 2013;Liang et al, 2014). Sartor et al (2003) reported a reduction in the black globe humidity index inside the facility from 83.5 to 82.4 during the critical period of the day (2 p.m.), besides reduction in feed conversion from 3.27 to 2.88, and increase in weight gain, from 0.97 to 1.02 kg a day.…”