The problem we had with feeding beech was about 14 years or more ago so the memory becomes hazy with the details. We definitely had one, possibly 2 fatalities and some poorly goats, although not all affected to the same degree. I know the goats were housed at the time and they had beech prunings from a garden in the village. It may have been copper beech which I understand is a variant on the normal beech rather than a different species. I did quite a bit of research at the time and was absolutely convinced that the beech was the issue, although I also hadn't expected it to be an issue. It is certainly possible to find reports of beech toxicity in cattle and horses and the thinking is the main poisonous agent is oxalates (same as rhubarb leaves). Beech is also known to contain small amounts of cyanide and saponins although probably not in large enough quantities to normally be an issue, as well as tanins. Some thoughts I have is that it may be that more ornamental varieties may differ in the amount of these toxins. The beech our goats may have been quite dry and old leaves which would increase the proportion of toxins. Sometimes different climatic conditions and different soil conditions can also affect toxin production in plants and beech is not common in naturally occurring woodland in our area. My last thought is that our goats at the time almost certainly only had hay/straw, some sort of commercial food, and the beech trimmings. They probably ate a large proportion of their diet on that day or two as beech, whereas if they have access to a hedge they may eat a bit and then move onto something else - in that sort of situation I have seen goats eat rhododendron and other plants that are indisputably poisonous and actually come to no home, as the poison is diluted by the other food they eat.
Certainly it's been interesting to hear other people's experience with beech, but we have avoided it ever since.
