I was about nine years old. Us kids were ordered by Dad not to watch a difficult calving. We disobeyed, hid, and regretted it, it was conjoined twins with one body and a divided head with two muzzles. They came out of the cow in pieces after being carved up with what looked like a long bit of cheese wire.
My Dad was really angry when he realised we had seen the whole thing and we got the job of pushing the wheelbarrow full of afterbirth to the poo pit. He was good at fitting the punishment to the crime!
Sorry to be gruesome but I have never forgotten it.