You all must have different feeds in Australia than we do in the US. Starter is the only medicated feed, not grower, and not fed until point of lay. It's usually medicated with amprolium, which as far as I know doesn't have a withdrawal period.The only time I have been told not to eat the first eggs is if the first eggs are laid whilst the pullets are still eating the pullet grower feed, or during the first two week transition to layer feed. This is because of the coccidiostat that is in the pullet grower feed. The "washout period" where the coccidiostat leaves the pullet's body takes about 2 weeks.