Ambiência e comportamento de leitões em duas tipologias de creche: avaliação e modelagem fuzzy

Abstract

The environmental conditions of the swine confinement facilities are of great importance for obtaining success in productivity, especially in the nursery phase, since this phase pre-establishes the development of these animals in the later stages. When the animals are exposed to uncomfortable conditions, they present altered behavior, such as lower feeding rates, thus compromising the productivity. With the exposed, the objective of the present work was to evaluate two distinct swine nursery facilities according to their thermal comfort, presence of gases, noise, and behavior according to the thermal conditions of the environment. The study took place at Granja Niterói facilities, located in the municipality of Lavras, MG, Brazil. The facility presents complete cycle swine production system, that is, the animals are confined from birth to slaughter. We used two styles of nursery stalls: nursery 1 with masonry stalls with fully slatted metal flooring, and nursery 2 had wooden stalls with fully slatted plastic flooring. The experiment was conducted in a randomized blocks design with split-plot scheme, which were composed by the nurseries (1 and 2) and the external environment, the subplots in hours (1 to 24 h), and the replicates of the collection dates (15 days). The data for air temperature (°C), relative humidity (%), and black globe humidity index (BGHI) were collected throughout the day at 10 minute intervals, being submitted to analysis of variance with the means compared by the Scott-Knott test at 5% probability. We collected the gasses, ammonia (NH3) and carbon dioxide (CO2) in 15 non-consecutive days, in addition to the sound pressure level and analysis by means of descriptive statistics. Animal behavior was analyzed by means of the behavioral frequency. With the behavioral analysis, we developed a fuzzy model in order to predict the comfort rate based on the behavior of the piglets in relation to age and temperature variation. The results obtained demonstrated that there was no difference between the two nursery types in relation to air quality, sound pressure level and thermal condition. However, there was difference between data collection times, with the morning period being comfortable and the afternoon period being thermally stressful conditions. The gas and sound pressure levels did not exceed the maximum levels established by the current regulations. According to the behavioral responses of the animals, the installations provided thermal comfort in less than 50% of the confinement period, with nursery 2 being more comfortable than nursery 1. The fuzzy model developed in relation to age of the piglets and the BGHI was proven adequate in predicting thermal comfort rates from animal behavior.