[Arnfields]

Make it with water, hens can tolerate a little milk but not a lot, besides porrige made with water still tastes nice and creamy  

Yes, made ours with water too - mostly.  There have been one or two days when there has been a little slug of milk too, and sometimes poultry spice or garlic powder (they wont touch the water if I put garlic in it)
Am sure they must be ok with some diary as live yoghurt is a regular 'tonic' on most forums for tummy problems.  Ours prefer fruit yoghurt - typical!