Leticia Cibele da Silva Ramos Freitas

External egg quality is an essential parameter of egg production as it relates directly to economic losses. This study evaluated the spatial variability of external egg quality in five naturally ventilated caged vertical aviaries. Differences caused by bird age and thermal and luminous variability within aviaries during winter and summer were analyzed. Data on aviary air temperature, relative humidity, light intensity, and external egg quality were collected at evenly distributed points along the aviary length within three levels of cages. The experimental design was completely randomized in a factorial scheme. In the summer, the highest air temperature and lowest relative humidity were found in central cages, mainly in upper center cages; hens produced eggs with a lower weight and shape index in this area. Similar results were obtained in the winter. In the summer, eggs with lower shell weight and thickness were also produced by hens housed in the central cages, but in the winter, the opposite result was obtained. This study of the spatial variability of external egg quality proved efficient in detecting areas within an aviary with poor quality eggs; improvements to design and management in these areas could help management improve production efficiency and contribute to a sustainable egg supply.

In this study, we aimed to assess the spatial variability of microclimate inside a closed compost-bedded pack barn (CBP) with a negative ventilation system during summer and winter. The research was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. For each of the stations analyzed, the following environmental mean variables observed inside a CBP were measured: air dry-bulb temperature (tdb), air relative humidity (RH), and windspeed, Temperature-Humidity index, and specific enthalpy. The kriging maps showed that the most critical housing conditions in the thermal environment were found, mainly, from the central part of the CBP, close to the exhaust fans. The analyses also pointed out that the system presented temperature gradients along the length, up to 3°C. During the summer afternoon, the entire region of the CBP was in a discomfort situation (tdb>26°C; RH>75%). During the winter, the measured environmental data remained within the comfort zone throughout the facility. However, probably due to the lack of thermal insulation of the material used to close the sides of the CBP, it did not allow spatial thermal uniformity for both seasons. It was also inefficient to keep the animals within the comfort zone for lactating cattle during the critical summer period.

The environmental monitoring in animal facilities that includes collected data storage in a robust, practical and feasible way is a constant challenge. The aim of this study was to develop a reliable data logger for monitoring the air temperature and air relative humidity of aviaries and to assess the adequacy of the design using commercially available reference standard instruments. The experimental data logger was installed together with a commercial data logger, a mercury thermometer and a calibrated Vaisala HMP110 air relative humidity probe in a meteorological shelter. Linear regression analysis was performed with the collected air temperature and air relative humidity to develop calibration equations. The Nash-Sutcliffe Index and the relative error were calculated to validate the experimental data logger. The air temperature and the air relative humidity calibration equations presented Nash-Sutcliffe of 0.993 and -0.281 for the commercial data logger, and 0.913 and 0.932 for the experimental data. The mean relative error of the air temperature readings was 3 and 1% and for air relative humidity 5 and 20%, for the experimental and commercial logger, respectively. The experimental data logger reliably stored all collected data without error to the micro-SD card. The experimental data logger can be considered low-cost and sufficiently accurate for monitoring air temperature and air relative humidity in aviaries, presenting field performance very close to the commercial data logger for air temperature measurement, and better performance than the commercial data logger for the measurement of air relative humidity.

The facilities for laying hens should be designed to provide thermal comfort and satisfactory luminosity for the production of quality eggs. The objective of this study was to evaluate the spatial behavior of thermal conditions and light intensity of facilities for laying hens with vertical cages naturally conditioned during winter and summer. Air temperature, air relative humidity and light intensity data were collected in 75 points distributed evenly through the longitudinal direction of the installation in three tiers of cages (first, third and sixth). Each point represented a set of coordinates (x, y, z), being the x-axis the lines (L1, L2, L3, L4, L5), y-axis the sections (S1, S2, S3, S4, S5) and z-axis the tiers (N1, N2, N3). The spatial behavior of the thermal conditions of the facility was held during the coldest period of winter and the warmest period of summer. The experimental design was completely randomized in a factorial scheme. In the winter, the temperature showed homogeneous behavior among sections and variable among lines. In the summer, the spatial variability of temperature and humidity was more accentuated than in the winter, mainly among tiers. For both seasons, the center of the facility presented lower light intensity than the lateral. From the spatial behavior of the thermal conditions of the facility laying hens, it is possible to verify the magnitude and variability of temperature, relative humidity and light intensity, identify vulnerable and deficit thermal regions and contribute to decision-making related to thermal conditioning and luminosity of the facility.

Este trabajo tuvo como objetivo desarrollar y evaluar un modelo matemático computacional, con base en la teoría de los conjuntos fuzzy, para predecir el confort térmico a partir del comportamiento de lechones, en función de su edad y del índice de temperatura de globo y humedad, en dos tipologías de instalación de preceba. La instalación 1 estaba compuesta por corrales de mampostería y piso de malla metálica, y la instalación 2 tenía corrales construidos con tablilla de madera y piso en malla plástica. La instalación 2 presentó una mayor frecuencia comportamental en la condición de confort que la instalación 1, con 39,32% y 38,16% respectivamente. Los valores da tasa de confort térmico estimados por el sistema fuzzy presentaron una desviación estándar media de 3,58% y coeficiente de determinación de 72,86%. El modelo fuzzy desarrollado mostró ser adecuado para la predicción de la tasa de confort térmico a partir del comportamiento de los animales.