[Henstock]

Apparently it's the lactose they can't digest, there's more info here
http://www.exoticpetvet.net/avian/dairy.html
But like anything I wouldn't think a little bit would do too much harm, I know people whose geese love cottage cheese!!! Parrots that love cheese and yoghurt! None of them have dropped dead yet! 

[Mel]

When my girls are moulting,especially upon a full one I do not give them layers,I keep them off for 3-4 weeks.maybe longer,I give them Nettex Mineral Powder,I have never got on with the actual spice for some reason.I mix this with cod liver oil and stir into their corn.They have limestone flour as a booster. Some days i hard cook eggs and grind this all up  and then mix this with some corn or with veg.

I know we all try different ways and different treatments which we are happy to use,I am sure our flocks are different and have different tastes so is good to find something yours are happy with. By using the above I can only tell you from experience that they spring new feathers from nowhere and always end up fully feathered, beautiful and shiny