Hi Thank you all for the advice, experience sharing and insights in the chicken health. I used to keep hybrids in the past (not the bantams type) and other than the dreaded red mite, i never had any problems at all. But now all of a sudden with this flocks things are rapidly on the decline, or so it seems. I am guessing that pure breeds are by nature more fragile...
For the feed Shadrach, I have reverted to the one I had before, with VermX is it... ? Can't remember of top of my head. I felt not all of them seemed to enjoy it and weren't eating much. To be fair I had not noticed that you could get anything else other than layers pellets... (Put aside for chicks and growers). Peckford doesn't show the signs / symptoms you're mentioning, so I'm guessing this is not the issue here.
I do think now that it's a mixture of two things... Impacted crop and the cold. I keep making sure he drinks as much as possible, I massage his crop regularly and try and help it clear but mixed with the cold - I have to clear his nostrils (sorry can't think of the proper name) everyday. His comb is not floppy but definitely a lot paler, and his skin around his face also pink to pale pink. Everytime I massage his crop, he doesn't gain quite a bit of colours. Still very sleepy, and has lost quite a lot of weight I think. His crop wasn't impacted at the beginning of him being sleepy, so that's only just come up recently. He is isolated with one of the girls who also seems to have trouble with her crop... And today we have lost Doris. I am nit certain as to why because although she has lost loads of feathers and was very scruffy, she seemed well enough to run around the garden. She did get a bit of a impacted crop too, but I did manage to clear it. I think the lack of feathers came about because of a visit from a fox. I think he got away with some feathers but nothing else from Doris...