This is a multi-bureau multi-industry conspiracy.

A little investigation is not going to get to the bottom of this.

The bird-flu and where and when the "inspectors" went through was highly targeted.

And the prices at the stores have gone up, even without those particular suppliers raising their prices.
As well as suppliers being forced to keep their old prices while feed, transport... everything has gone up.

This whole thing is text book conspiracy.
So big, no one would believe it.