[allotment-shed]

A local farmer has offered me a load of well rotted horse and cow manure that is mixed, but I am not sure about the cow manure part on an allotment. Grateful for any opinions on this.
Many thanks.
Ron

[Yorkie]

As long as there's no herbicide contamination it is all good.  There's an article on the main website about the different types of manure.

[trunk monkey]

The mix should be fine. I believe the cow manure is less nutritious due to the cow's four stomachs extracting most of the goodness out of it, but otherwise ok.
Trunky

[Goosegirl]

Any manure is good, though some "hotter" than others as it rots down. It's used more to condition the soil texture rather than for nutrition but you still get some goodness out of it.

[moose]

Cow manure is supposed to have less weed seeds than horse- again to do with it's digestive system.

[beesrus]

As long as there's no herbicide contamination it is all good.  There's an article on the main website about the different types of manure.

Jay G, I have had a good look through those all those website manure articles and can't seem to find any information on the herbicide contamination problem you refer to, that can badly affect cow manure, and horse manure to a lesser extent, and through that, ruin peoples' crops. Lots of good info on the +s and -s of all the various soil amendments, but nothing at all about the herbicide problem. With it being such a huge problem over the last few years that affects all of us growers, could you possibly point me toward the article that gives some info on the problem.

[New shoot]

It was Yorkie, not JayG, that replied beersrus and she just said there was an article about the different types of manure, not one about herbicide contamination.

The farmer who has offered the OP the manure should be able to say whether this would be an issue or not.  Failing that, this subject has come up several times and the usual advice is mix a bit into some soil and put in a pot.  Sow a few fast growing seeds like beans and see if the seedlings grow normally or not.  Its a quick and easy check to do before you spread manure all over the plot and find you have a problem 

[Kristen]

The main herbicide that causes the problem is Aminopyralid - in case using that as a keyword helps locate suitable information.

[mumofstig]

A few links here from John's info pages
http://allotment-garden.org/garden-diary/3120/potatoes-weeds-aminopyralid/

[beesrus]

Thanks Mos for those links... very helpful. I see this forum initially did have a part to play in trying to erradicate the problem.

Quote....
" When this effect first became apparent, I’m very proud to say this website was instrumental in bringing the problem to the public attention and a campaign to stop it developed.".

Well done to the forum. Long may it continue.
In reality, it is sadly difficult to ascertain if a farmer's/riding school's manure is safe, as the problem can be brought in on hay and feeds unknown to the supplier.