The New Zealand Plant Conservation Network

I had alot of this plant in my garden.I since have removed them and poison d the trunks.The dead plants are still on my section preety much dead.My question is are the leaves still poisonous after the plant is dead for I have farm animals around it .

Dried leaves would still be toxic and stems and roots are also toxic. I'd play safe and remove all the above ground parts to one heap and compost it down.

I am intrigued that you had Atropa bella-donna - I have yet to have seen this species wild in New Zealand, and I have never seen it in the Waikato. Are you sure of the identity? Do you have images of your plants (before you killed them) that you can post so that I check the identity. Irrespective of my interest, if you have this species then Graeme is correct.