Early maturation (precocious sexual maturation) in male salmon causes welfare problems from physiological changes that impair health and reduce productive life.
Early-maturing male salmon experience welfare impairment from the physiological consequences of premature sexual maturation. Immune suppression associated with maturation increases disease susceptibility. Physical changes including jaw development (kype) can impair feeding. Precociously mature fish have reduced welfare and often die before reaching market weight. Management approaches that reduce early maturation prevalence through photoperiod manipulation and all-female production reduce these welfare costs. Welfare monitoring that identifies early maturing males allows early removal before welfare deteriorates significantly.