Comparison of Temperature and Humidity inThree Types of Outdoor Farrowing Huts

Abstract

<abstract><title><italic>Abstract. </italic></title> This study examines the temperature susceptibility of outdoor swine farrowing (birthing) huts made of three types of materials: plastic [designated as green (G) hut], galvanized steel [silver (S) hut], and plywood [orange (O) hut]. Three huts made from each of the three materials for a total of nine test huts were used. Temperature data loggers were installed on the ceiling of each hut. A data logger, typically used in building structures, was installed to measure the temperature and humidity in the field. Data were collected every 15 min for 10 days in April (first trial), and for 14 days in January (second trial) and data for each 1 h period was pooled. The air temperature, relative humidity, and solar irradiation for 2 m above the ground level were obtained for modeling hut temperatures using an artificial neural network from State Climate Office of North Carolina. Data were analyzed using SAS 9.2 software, and PROC GLM software was used to obtain the least squares means of the temperatures and the humidity for each hut. Two parameters, type of hut and time of data collection, were included in the statistical model. The least squares means of the temperatures and the humidity for each hut differed significantly from each other and were estimated as 22.4°C, 20.4°C, 20.7°C and 70.0%, 70.8%, 65.9% for types G, S, and O in the first trial, and 8.5°C, 7.2°C, 7.7°C and 78.7%, 77.2%, 65.0% in the second trial, respectively. In summary, the wooden (Smidley^®) huts seemed to perform the best, the English type metal huts were acceptable for temperature but had higher humidity levels, and the plastic (Nesting Box^®) type of hut, recommended for use inside a larger shelter such as an outdoor hoop structure, performed the poorest in this situation. A data-driven model based on a dynamic neural network was developed and validated for prediction of hut temperature as a function of solar irradiation and outdoor air temperature for other times throughout the year. Overall, these results may help small-scale pig producers choose the appropriate type of swine farrowing hut for outdoor environments.