Efeitos de dois sistemas de acondicionamento sobre os índices ambientais e zootécnicos de poedeiras semipesadas.

Abstract

The objective of this work was to measure the effects of different systems of environmental conditions on the performance of red commercial semi-heavy hens in the three creation phases among September of 2003 to May of 2004. Two hangars were used with different thermal packaging, one with asbestos cement tiles covering (GTA) and other with ceramic tiles covering (GTC). The temperature of the air, indexes of temperatura of the black globe and humidity (ITGU), thermal load of radiation (CTR), relative humidity of the air (UR) and noise leveis inside the facilities were evaluated. The hens performance was evaluated by the total production and for the quality of the eggs. The experimental phase was accomplished at creation hangar for commercial hens. The environmental indexes were measured daily, in intervals of two hours, of the 8 to the 16 hours, in the internai and externai áreas of the experimental hangars. The analysis of the averages showed that in the birth phase, during the first weeks of life, there was failings in the heating of the bird, with temperaturas reaching at the most 31,27°C inside the facilities, and starting from to 5th week there was an inverse behavior and the facilities didn"t provide appropriate leveis of comfort with high temperaturas. The phase of rebirth was the one that presented larger flaws in the leveis of thermal comfort and the postura phase presented appropriate leveis of comfort in most of the schedules analyzed during the experimental phase because of the high rain indexes registered in the area in the months of research. The results were analyzed by statistical methods through the test t of Tukey at the levei of 1 and 5% of probability. It was concluded, based on the environmental thermal indexes, that the system with ceramic tiles presented the best room temperature results, ITGU, CTR and UR in the phases of recreation and postura and based on the indexes of productive performance of the birds - the production reached average of 90% in GTC and 87,20% in GTA. In relation to the quality of the eggs, there were statistical differences (P <0,05) among the birds maintained at the different hangars in relation to the weight of the egg and of the egg white, while the other variables didn't present differences.