Stimulation of Secretion of Shell Gland Fluid and Calcium by the Presence of Ovum or Ovum-like Mass containing Artificial Yolk in the Oviduct Uterus of the Hen

Abstract

Shell gland fluid was collected from the lumen of the oviduct uterus (shell gland) for 20 minutes at various hours after ovulation of the second ovum (C2) of a clutch and after oviposition of the terminal ovum (Ct) in intact hens and in hens receiving or not receiving an insertion of an artificial yolk (an elongated spherical agar mass of 1.0 cm in diameter and 1.5 cm in length, and 3.0g in weight) into the infundibulum. The volume in intact hens having a normal ovum and in hens receiving the artificial yolk was significantly greater at 5-6, 10-11, and 20-21 h after C2 ovulation than that in hens not receiving the artificial yolk (P<0.05), although this difference was not apparent at 0.5-2.0 h and at 25-26 h. A similar difference was also observed in the amount of calcium in the fluid calculated from the concentration which was measured by the use of a kit. In hens after Ct oviposition, the volume of fluid and the amount of calcium were significantly less at 5-6, 10-11 and 15-16 h than in hens after C2 ovulation having a normal ovum or the artificial yolk in the uterus at corresponding hours (P<0.05). The results suggest that the presence of an ovum or ovum-like mass containing the artificial yolk in the uterus of the hen may stimulate the secretion of fluid and calcium from the gland of the uterus, and also suggest that the ability for this secretion may decrease at the end the egg-laying cycle.