Most poaching deaths are most certainly not for food. Why would the poachers go for rhino, elephants when there are millions of wildebeest and impala to eat rather than go for ones that are hard to find. It is because of the ivory and horn.
I lived in Africa for 18 years and have seen poaching with my own eyes and they were after antelope for food not horn or ivory.
They didn't give stats or a percentage at the time, I've been googling and can't back it up with anything substantial, so perhaps they over-stated it. They did talk all about how elephant meat is highly desired though, apparently that's a well-known thing.
They also talked about some people that will scare lions off their kill (not elephant), quickly cut some off, and run away with it before the Lions wised up and came back. Madness.