Long-term effects of aviary management and dietary fiber during pullet rearing on performance, egg quality, integument, and keel bone condition in extended laying cycles.

Extending the laying period is a key objective in modern egg production, as it reduces resource use and improves economic efficiency. Pullet rearing can exert long-term effects on welfare and performance, but little is known about whether specific, practically applicable rearing interventions have persistent and trait-specific effects throughout extended laying cycles. The aim of this study was to investigate long-term effects of dietary fiber during pullet rearing and aviary opening time on welfare and performance during an extended laying period of 84 weeks. In a 2 × 2 factorial design, non-beak-trimmed pullets (Lohmann Brown Classic) received either a standard (Fcon) or moderately elevated fiber diet (F+) and aviary levels were opened early (day 14/17; M14) or late (day 28/31; M28). After the controlled rearing experiment, 1,520 hens were housed under identical aviary conditions in 16 pens until 84 weeks of age, allowing persistent effects of the rearing treatments to be evaluated during an extended laying cycle. During lay, plumage damage (PD), skin injuries (SI), keel bone deviations (KBD), and keel bone fractures (KBF) were assessed at four time points. Laying performance, feed intake, mortality, and egg quality traits were also recorded. Binary logistic regression showed lower prevalences of PD, SI, and KBD in M14 compared with M28 (P ≤ 0.004). Increased dietary fiber during rearing was associated with lower KBD but higher PD (P ≤ 0.042). Treatments had no effects on laying performance or feed intake (P > 0.05), but affected albumen consistency at 80 weeks of age, with higher values in M14 compared with M28 (P = 0.002). Survival analysis showed no effect of aviary opening time (P = 0.591), but a significant effect of diet (P = 0.015), with higher survival probability in Fcon than in F+. Earlier aviary opening had persistent beneficial effects on integument and keel bone condition, whereas increased dietary fiber provided no consistent long-term benefit. Thus, rearing interventions can have trait-specific carry-over effects into extended laying cycles. Scientific section Animal Well-Being and Behavior.