If it still smells of poo generally speaking its too early to use it. Better to put it in a heap open to the weather and let it finish rotting. If you have a big enough compost heap you could add it to that in small doses. But it also depends where you want to put it. On an open bed with nothing planted until next year it would do no harm to spread it now but don't put it near plants. If you're short of space and have an unplanted bed you could alternatively put the heap there until its ready. With well rotted manure you can add it in the autumn, but on light sandy soil its better to wait until Spring as nutrients wash out more easily in a light soil. If you are adding lime to a heavy clay acid soil don't add it at the same time as your manure - leave at least three weeks between.
The main thing is don't put fresh manure round your plants (though I have to say that my Mum used to pick up fresh manure from the street and put it straight on the roses with no ill effects! )

Steragram: I'm guilty of picking up fresh smelly horse poo, and of depositing on my roses.

They do very well on it. I wonder if it's because they are deep rooted?

Horse manure needs to be very well rotted, at least a year before going into the ground - two years is better! Also if you are going to put it where you plan to grow vegetables beware that the hay the horses eat could have been sprayed with a herbicide which has no effect on the horses themselves but can have effect on the grown of vegetables, possibly flowers too but it has been noted in veggies.

Thanks, I didnt think it was that long winded

Dunno Grannyb, but yes, they do thrive on it!
MG, any way of knowing?

You can bung it in your compost from fresh Alan as long as it is not too much.

Steragram, not that I know of, a lot of allotment holders are experiencing this but there does not seem to be a way of knowing if the dung has come from horses fed with hay that has had this herbicide sprayed on it. I'd really like to know more... I think we are pretty safe up here but am still cautious.

:((
S