birds that received a 0.09% Ca ration for 10 d returned to 50% production in 4 wk. Hens that received a 0.09% Ca diet for 14 d reached 50% production by the eighth week after molt initiation (Douglas et al., 1972). Gilbert and Blair (1975) observed that hens molted with a diet containing 0.05% Ca for 6 wk returned to 50% production by the eighth week after initiation of treatment.