Programas de iluminação em ambientes climatizados para suínos nas fases de crescimento e terminação

Abstract

This research was conducted with the objective of evaluating the influence of artificial light supplementation on the productive performance of confined pigs in environments with and without air conditioning, as well as the thermal characterization of the facilities during the growth and finishing phases of the animals. The research was carried out at the Experimentation with Swine Laboratory of the Serra Talhada Academic Unit (BES-UAST) of the Federal Rural University of Pernambuco (latitude 07.98° S, longitude 38.28° W and altitude 444 m). We used 27 growing pigs were obtained from matrices with genetic composition 3/4 Duroc, ¼ Pietrain, covered by Duroc male. The experiment was carried out from september to november 2017, totaling 61 days. The animals were submitted to the following variation factors: bays without air conditioning (BS), bays with forced ventilation (BV) and bays with evaporative adiabatic cooling (BR), associated to different light supplementation programs: 12 h of natural light, 12 h of natural light + 4 h of artificial light and 12 h of natural light + 6 h of artificial light. During the whole experimental period, the data of the meteorological variables inside each bay and in the external environment were registered; physiological responses; behavior and performance of animals. The experimental design was completely randomized, in a 3x3 factorial arrangement, randomly distributed in nine bays, with three replicates. The evaporative cooling system attenuated the action of stressors and ensured adequate thermal accommodation for the animals in the growth and termination phases. The physiological responses, respiratory rate and rectal temperature indicated that the animals submitted to evaporative cooling, independent of the lighting program, were housed in a thermal comfort condition in both breeding phases. Weight gain and feed conversion were positively influenced for animals exposed to evaporative cooling in the growth phase. The performance in the termination phase was superior for the animals submitted to evaporative cooling, with reduction of 16 days at the slaughter age of the animals. The supplementary lighting program for 6 hours promoted better feed conversion in the finishing phase. The animals in the growth phase, housed in forced ventilation bays, exposed to supplemental lighting for 6 hours, presented a greater frequency of access to the feeder. The pigs submitted to evaporative cooling had a higher frequency of ingestive activity and a wide lethargic expression, typical of the breeding phases studied. In addition, the animals presented a higher frequency of comfort behaviors, stimulated by the better thermal conditioning in the housing.