When you have y/birds in the nest this time of year dont put freezing cold water in the drinkers, add a bit of hot water to it just to take the chill of.
-------------------------------------------------------------------------------------
You cant stop smashed eggs from occurring but if you add a dummy egg to each nest (especially if you have the odd troublesome yearling) you can at least salvage their nesting condition, they'll carry on sitting the dummy and you can give them a baby when they were due to hatch.