Conforto térmico e desempenho de pintainhas criadas em gaiolas sobrepostas no semiárido

Abstract

Brazil has been standing out in the poultry production of laying, especially due to investments in research and technologies, however, several Brazilian regions, such as the region of the study, present few expressive numbers due, among other factors, to the climatic characteristics. The objective of this research was to evaluate the effect of the thermal environment of a commercial aviary on the performance of chicks in the initial phase of one to 42 days of age, in the semiarid region. The experiment was conducted in a commercial farm that has a conventional system, in the municipality of Cuité / PB, during the months of November to December 2018, a period characterized as summer. 10,000 chicks were housed in overlapping Lohmann LSL lineage cages. The environmental variables were evaluated: temperature and relative humidity of the air for the internal and external environments of the installation. The thermal comfort indices evaluated: temperature index of the black globe and humidity and radiant thermal load. The performance was evaluated by means of live weight, weight gain and the evaluation of the performance data was performed by comparing the data obtained with those recommended by the management manual of the Lohmann LSL strain. The results indicated that for the environmental thermal conditions, based on the thermal comfort indexes, the birds were in conditions of cold stress, at night in the first weeks. As for the relative humidity of the air, the smallest values with small variations were registered in the daytime, however in the nighttime high values and greater variation were obtained. It is concluded that even using the electric heating system and hoods, this system was inefficient, since the environmental indexes and thermal comfort were below that proposed for chicks in the first and second week of life. From the third week onwards, the globe temperature and humidity index did not remain within the ranges considered ideal for birds, except for the radiant thermal load that remained within the range proposed by the literature. However, the variables analyzed did not compromise the performance of the chicks, remaining close to the considerable ranges ideal for lineage. Evidencing the adaptability of chicks to the environment that were able to minimize the effects of thermal stress.