Most Mexican food as we know it as today is really Tex-Mex. It's been Americanized.
Before the Europeans arrived there were no beef, pork, chicken or cheese in Mexico. The Mexican diet consisted of maze (corn) beans, squash and peppers. In 1860 there was still only one dairy in the entire country of Mexico. It was owned by a German immigrant who was the only source for cheese.
Hogs were raised for only one purpose in Mexico, lard. Mexicans didn't start eating pork until the late 1800's. Lard was used for only two things, cooking and for greasing the hair. That's where the term greaser comes from.
Chili con carne was created by a German immigrant in Texas during the 1800's..
If you ate a Jack in the Box taco during the late 70's or early 80's, the meat had kangaroo meat in it.
Burro meat isn't bad. Most Americans can't tell the difference between beef and horse meat.
Have you ever drove my a wind farm and noticed all of those Tyson chicken trucks ?