Yes... I found it very interesting in the hotbed link, that grain fed horse manure was specified for the purpose of a winter hotbed.
We are not in a grain producing area here, and everything imported to the island is expensive. The normal practice here in Conception Bay is that a household with one or two horses has pasture for them, although some grain may be fed to supplement the diet in winter. These households also use the manure in their own garden. In this case, the owner was giving away what he didn't need, so my only cost is the delivery.
There is some hay made here on the Avalon, but where I have seen it, it appears to be on very old stands of grass. These are not fields in rotation that would need herbicide applications every year if ever - it's not easy for any weed to invade that perennial sod afaik!. The more likely source of herbicide if any would be grains that are imported and fed to the animals as a small portion of their diet.
There are a few commercial stables in the area and I used to buy manure in the past from a racehorse stable in the Goulds. These animals were probably grain fed, so the sales pitch may have been true, that it made everything grow faster.
The manure was always very well rotted and older than what I have here this spring. Also full of horseshoes - there are dozens around my property from back when, and syringes, which is not so nice. I never had any problem with the stuff other than the inevitable weeds, but it may have been pre-herbicide days.
