"..........I have just been given 2 tonne of cow muck that's been rotting
down for just 3 months ........"

Any fresher and the cows could have delivered it personally.

I would be inclined to put it into a heap and leave it till the Autumn to
rot down, then spread it on the borders and let the worms work on it over
the winter

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk