Just been down to check on the chickens and noticed they all have swollen crops; they feel soft and fluid filled rather than hard. Five out of the six are affected, the only one who isn't is currently in a broody box. The only difference between them therefore is the greens I gave them the last couple of days (broody not had access to the greens but on same food otherwise). They had some bolted lettuce and fennel tops from the veg plot. I'm thinking maybe the fennel either doesn't agree with them or the fronds have caused a blockage.
At the moment they all seem bright and breezy and still eating but I'm a bit worried they'll all keel over tomorrow. If crops are still swollen tomorrow do I need to try and drain them? And does anyone know whether fennel is bad for chickens?