SUMMARY
The objective of this work was to evaluate the effect of specific gravity of eggs from broiler breeders of different ages in the yield of incubation and the weight of post-hatch chicks. Were used 3.072 eggs from two batches of broiler breeders, Cobb - 500®. The eggs were distributed a completely randomized design in a 2x4 factorial design with two broiler breeder ages (53 and 64 weeks) and four different egg densities (1.070, 1.075, 1.080, 1.085), totaling eight treatments and four replications (with 96 eggs per experimental unit). The evaluated variables were the egg weight (g), the hatching rate (%), the fertility rate (%), the weight loss of eggs during the incubation period (%) and the ratio of the weight of the chicks/egg weight (%). The results were submitted to analysis of variance, being that the effect of density was assessed by polynomial regression and the age effect of breeders by F test at 5% probability. Weight losses of eggs, except for the densities of 1,075 and 1,085, from breeders with 53 and 64 weeks of age, respectively, were within the values recommended in the literature. The chick weight was proportional to the weight of the egg, representing on average 68% and no differences between age and density of broiler breeders. The age of the breeders exerted influence on the yield of incubation, and the best results (p<0.05) obtained by eggs from breeders with 53 weeks of age.
density; hatching eggs; hatching rate; incubation