The objective for broiler breeders is to optimize the production of fertile eggs that hatch into healthy and efficient-growing broilers. Body weight, body composition, physiological, and metabolic thresholds must be reached in order for sexual maturation of broiler breeder hens. Investigation on these thresholds will provide a better understanding of the physiological mechanisms driving the interaction among growth trajectory, feed allocation, sexual maturity, metabolic status, and reproductive axis. How can applied research help industry and producers understand how feeding practices influence reproduction? How have genetic changes over the years influenced bird metabolism and reproductive efficiency? Do feeding practices need to change and how?