oh and my bin says - NO ANIMAL WASTE but think that's more of a regulatory thing than because it won't break down
All mine goes on the muckheap at the yard, as it is all biodegradable. I have no idea as to how good it is for plants tbh, horse manure is of course amazing for plants but not quite sure on the composition of guinea poo. Their guts are not dissimilar to horses though so would imagine it would be fairly good...I now worryingly want to research guinea pig poo...