The aim of this study was to evaluate the effects of relative humidity in incubators (RHI) and breeder hen age on hatchability, hatchling quality and performance of progeny. 10,840 eggs were incubated, and the treatments were defined by the Lohmann LSL(r) breeder age (26, 41 and 56 weeks) and the levels of RHI (48, 56 and 64%). After incubation, 1,620 female chicks were raised in a conventional experimental shed, according to the treatments, until 12 weeks of age. To assess the hatchability of fertile eggs and unviable female chicks, the experimental design was randomized blocks in split plots design. The plot factor was the RHI and the subplot was the age of the breeder hens. The blocks were made by the floors of the incubation carriages, where each floor contained a repetition of each breeder age. The nine treatments consisted of 14 repetitions each. The repetitions were trays of incubation, with 1,204 eggs per treatment. To evaluate the performance of the progeny, the experimental design was completely randomized, consisting of a 3x3 factorial scheme with six replicates of 30 birds in each treatment. Hatchability of fertile eggs was higher (P<0.05) with the use of 56% relative humidity during incubation, regardless of breeder age, and the eggs from the oldest breeder hens (56 weeks) had lower hatchability (P<0.05), regardless of the level of relative humidity inside the incubator. No effects of breeder age and RHI on the percentage of unviable chicks were observed. The RHI or the age of the breeder hen does not affect the performance of progeny.
age; breeder hen; incubation; performance; relative air humidity