When to switch to layer? 18 weeks? 20 weeks?

[shelleyd2008]

I feed my quail medicated feed, and we eat their eggs. I was told (can't remember by whom) that once the medicine that is in the feed gets as far as the egg, there isn't enough left to cause any damage.

 

[wombat]

This doesn't say whether you can eat eggs if you feed medicated feeds right up until lay, but it does indicate that you should stop feeding medicated feed to layers by week 16:

http://www.poultry.msstate.edu/extension/pdf/is1214.pdf

and Oregon State says this:

Medicated feeds
Most commercial starter diets are medicated to prevent common yet serious diseases in chicken flocks. Medications are less common in grower or layer diets. Feeds that contain medications are labeled as such.

Check the label for warnings concerning the medication used in feeds. Withdrawal dates will be indicated on the label if there is a risk of the medication's presence in the eggs. Feed medications are highly researched and regulated, so you can be confident that the eggs are safe to eat if you follow the label instructions.

If you wish to use nonmedicated feeds, they usually are available or can be ordered. However, in some cases, mortality levels, especially in young chicks, may rise to unacceptable levels if nonmedicated feeds are fed.

at
http://extension.oregonstate.edu/catalog/html/pnw/pnw477/#anchor1132074