Improvement in productivity of incubation of thermal handling of eggs of distinct light matrix weights

Abstract

The objective of the experiment was to evaluate the influence of thermal manipulation on the improvement of hatching eggs of different weights of light matrices in the last embryonic stage. The experiment was carried out in a commercial hatchery of light laying hens, located in Birigui - SP, Brazil. 1950 light-colored eggs of the Dekalb White commercial strain were used. The eggs were classified among different sizes and n in incubation trays. In the period from 19 to 21 days, two incubator machines were used, where the first machine maintained the temperature and humidity values of the hatchery's standard air (37.0 ° C and 60% RH) and in the second machine the temperature was adjusted to 37.7 ° C with 60% RH. The treatments differed according to the residence time in the second machine, and egg weight (G and M) controls T1 (0h-G) and T6(0h-M), 1 hour T2(1h-G) and T7(1h-M), 3 hours T3(3h-G) and T8(3h-M), 6 hours T4(6h-G) and T9(6h-M) 9 hours T5(9h-G) and T10 (9h-M). The design was completely randomized, in a 2X5 factorial scheme. Regarding thermal stimulation, the best results were observed in the 1h-G treatment. However, in the productive life of these birds, the thermal stimulation showed no influence. Concluded that for large eggs (G), the residence time of 1 hour (T2), obtained a better index of commercially viable females and lower rates of late-stage embryo mortality and shelter.