抄録
Immunoglobulin Y (IgY) is transferred passively from maternal circulation to the yolk. The aim of this study was to determine whether the concentration of yolk IgY is affected by forced molting in hens. Molting was induced in laying hens of 515-days-old with 3-4 eggs in a sequence by the withdrawal of feed. Yolk samples were collected before the feed withdrawal (premolt), and 4 and 10 days after relaying (postmolt). Serum samples were collected before and 2 days after feed withdrawal, 3 days after cessation of laying, 4 and 10 days after relaying. The concentrations of IgY in the yolk and serum were determined by ELISA. IgY concentration in the yolk was significantly greater in postmolt hens than that of premolt hens. Although IgY concentration was slightly decreased in the yolk 10 days after relaying compared with 4 days after relaying, it was still significantly greater than that of premolt hens. Serum IgY concentration increased significantly during molting and remained higher in hens until 4 days after relaying. In the hens 10 days after relaying, serum IgY concentration decreased significantly and returned to almost a same level as that of premolt hens. These results indicate that IgY concentration in egg yolk is increased during early phase of postmolt.
