Effect of calcium supplementation on growth of shell-less cultured chick embryos

Chick embryos grown in shell-less culture are calcium-deficient by 9 days and retarded in growth by 13 days of incubation (Dunn and Boone, Poult. Sci., 56:662-672, 1977). To determine whether addition of exogenous calcium might stimulate growth and/or survival of cultured embryos, calcium supplementation was attempted. Calcium supplementation between days 11 and 17 resulted in significant increases in both total embryo and serum calcium. Addition of shell pieces oriented with shell membranes onto the chorioallantoic membrane (CAM) resulted in significant stimulation of calcium transport by the CAM. However, growth of supplemented embryos was not increased to the same degree as were embryonic serum and total calcium levels. It is concluded that at least one factor other than calcium deficiency is responsible for retarded growth of shell-less cultured embryos.