Abstract
Inhibitory effects of prostaglandin F2α, arachidonic acid and phosphate solution on the eggshell formation were investigated in Japanese quail. All injections were performed intrauterinely 8h before the predicted oviposition. Prematurely oviposited eggs distinctly presented significantly lower values of eggshell weight (64-70%) and eggshell thickness (65-70%) than those of control (p<0.01). Spontaneously oviposited eggs, of which averaged oviposition intervals were approximately 24h, also showed significantly lower values (p<0.01) than control in eggshell weight and thickness (71-79% in both). When indomethacin was pretreated, oviposition-inducing effect and inhibiting effect on eggshell formation were disappeared in injection with arachidonic acid, whereas not inhibiting effect on eggshell formation but oviposition-inducing effect only disappeared in injection with phosphate solution. These results indicated that prostaglandin and phosphate solution had the inhibitory effect on the eggshell formation.
