its a sad day when you need a immune booster i think if a bird needs antibiotis its not worth having in the long term .why would you need a immune booster in the first place its something i wouldnt use even if it was for free .as for belguim birds getting all this and that i think alot of our own fancier use a lot of things they wont tell you about just to try and gain a little bit of advantage. i bought 24 birds last year to muck about with from the spring exchange and leir market killed 6 lost6 12 left from a so called hard young bird season half left which is about average going by fellow club members so there not all bad