http://www.patient.co.uk/showdoc/40000480/ the above link should explain the problem far better than I ever could. The other problem is things such as heavy metals in fresh er presents.....humans manure is the same . To leave any fresh dog or cat manure on flower or veg beds , would, for working purposes, be very unpleasant, for obvious reasons. So the best thing would be to compost any cat/dog manure ,well, and then only use it on non food areas if possible. It does depend on what the animals eat to an extent, but any manure even human can be used ,as long as it is well composted. The best way to do that would be compost as normal ,with as much other material as possible and then when that is all completely changed to compost and the worms ( thats the banded type 'Tiger' worms not earth worms ) have worked their way through it , you should be able to use it ok .You can set up a wormery very easily and bypass the ordinary compost heap stage , if time were a problem .
On the subject of horses , yes you are right Stephen, I have 3, well 1 horse and 2 ponies. The idea of getting the big horse was to use her for work . However , she was my first horse and teaching a horse to plough isn't that straight forward. You would ,really, as a rule use 2 horses to plough with , as it is a very hard thing for them to do . The plough itself weighs as much as a man . Another problem is the cost of all the gear ( all the leatherwork etc) is very high , far to much for me to get new . I have now , just about got most of what I need , even the plough , and it remains for me to now teach my big horse to work .She is a good learner but as with all things time is the killer. I do have a very big tractor (100 HP 2-4 wheel drive) thats one of the really big type. I don't however have a tractor plough ....lol. The other thing is with the veggie plot being comparatively small , the tractor just would not be feasible , and even the horse only just . It is all to do with headland , turn round space at each end of the ploughed furrow. The tractor would be ok for shifting the stone in summer, it would kill the land in winter, but I don't have a trailer for it yet . The horse would shift it too , but I hit the problem of working gear/tack again and a wagon to pull . So .... until I get everything needed the only thing to do is get a good fork and spade and get dirty.
cheers
Russ