EFFECTS OF THE MATERNAL THYROID STATUS ON EMBRYO PHYSIOLOGY AND HATCHABILITY OF COMMERCIAL TURKEY EGGS

Fertile turkey eggs produced by commercial hens fed iodine or triiodot hyronine were compared with those from hens fed a control diet to obse rve the effects of the maternal thyroid status on the energy budget of turkey eggs. Dietary iodine improved hatchability, decreased the numb er of dead pips, and maintained blood glucose concentrations during pi pping and hatching with less reliance on hepatic gluconeogenesis (as a ssessed by glucose-6-phosphatase activity) compared with controls. Hat chability of eggs from hens fed triiodothyronine was not different fro m that of control hens but was less than those of iodine-fed hens. The data suggest that the maternal thyroid function of commercial breeder hens can influence hatchability of their eggs and that dietary iodine may be a means to improve hatchability of commercial turkey eggs.