Layer persistency is discussed when egg production begins to fall. By then, the causes may be months old. Late-cycle output reflects more than the diet being fed at 60 or 70 weeks. Pullet body weight and uniformity, skeletal development, the transition into lay, feed intake at peak, egg mass, calcium supply and disease challenges all leave a biological record. The hen carries that history into the second half of the cycle.
I once reviewed a flock where management wanted a stronger late-lay diet because production and shell quality were declining sooner than expected. The later feed deserved attention, but earlier records told a more important story. Pullets entered lay unevenly, intake lagged as production increased, and body weight was lost around peak. The company was trying to repair at 60 weeks what had been compromised near 20 weeks.
