Efeitos do momento de transferência para o nascedouro e da idade da matriz pesada sobre o status fisiológico de embriões e pintos, rendimento da incubação e desempenho de progênie

Abstract

Two experiments were conducted, the first being divided into three experimental phases. Eggs and chicks were used in the experiments from two batches of Cobb broiler breeders ® aged 33 and 63 weeks, considered new and old birds, respectively. In the first phase of Experiment I, looked at the quality of hatching eggs. The treatments were defined by two broiler breeder ages. In the second phase, were related to performance evaluations of incubation and the third phase, were assessed physiological parameters during incubation of embryos and chicks after hatching. The treatments of the second and third phase of Experiment I were defined by breeder age (33 and 63 weeks) and by the time of transfer of the incubation chamber for the hatchers (15, 17 and 19 days). The second experiment aimed to verify the effects of broiler breeder age and transfer time of incubation egg chamber to the hatcher on the progeny performance. The treatments were considered the same as those used in the second and third phase of the experiment I. It was concluded that eggs from older broiler breeder hens have lower quality of shell eggs than the new ones. The shell membranes in eggs of a new broiler breeder hens are thicker and play important role in shell quality. During the last third of incubation, the embryos were able to respond to different physiological conditions of temperature, relative humidity, ventilation and turning that they were submitted. These mechanisms allow, regardless of breeder age or of different periods that the embryos remain in the hatcher, that occurs stability in physiological balance of the chicks after hatching. Regardless of breeder age, the eggs transfer from the incubator to the hatcher at 15, 17 or 19 days of incubation does not interfere with embryonic mortality, hatchability and chick weight at hatch, as there is no influence on the progeny performance. It is possible to adapt the incubation transfer management to the hatchery logistics needs or reduce the period of eggs incubation in the machine to increase the flow of production, without prejudice incubation yield and bird performance in rearing.