You shouldn't keep chickens with turkeys as there is a risk of Blackhead with the turkeys

I think there maybe a lot of opinions on this one, un-equaly divided.  I am going to stick my neck out here..

Turkeys I found (with luck) can be kept with chickens, as long as you worm everything well and efficiently to minimise the risk to the blackhead parisite.  It is not particularly recomended though, but I know several keepers who mainly have chickens, and also a few turkeys.  They run together, and if consideration is given to conditions such as size or roost etc there maybe no problems.
I pondered over this a year or two, and went against common recomendations of not mixing the two. I hatched chicken and turkey eggs in the same incubator run, everything was fed turkey rations from day one......The hen chicks seemed to do very well on the turkey starter crumb with its high protein content (in fact they looked so well, I am considering feeding turkey crumb this year to my hen chicks), and I never had any problems with mixing/aggression of the birds.

The whole flock of 8 chicken growers and 7 turkeys got on like a house on-fire.   Other people on the forum/s if I remember right may have had some mixing problems.

All of my birds free-range, except when I am keeping breeding groups together.  Turkeys, if allowed to free-range will eat everything and anything, and once hardy and allowed freedom will drop the demand for turkey grade feed pellets, and seem to ignore these some days, only taking mixed corn.       I have never tried to keep the two in close confinement..... and maybe I have just been lucky in my initial year of turkey rearing. 
I will be doing the same this year...

My spare 'Chrismas dinner' now weighs 30lb's plus, and now roosts down on the floor with his new roost-mate , a silkie bantie rooster......than be up on a perch by himself.