The cows are a (bad) metaphor for the means of production, obviously. The metaphor sneakily puts you in the shoes of a capitalist and, whoa, it turns out capitalism is good when you are one of the few it benefits.
I can't believe I was once taught this bullshit in school.
I remember reading one of these except it went into a ton of weird things like, Surrealism: You have two cows. The government buys your giraffe. Now you have three ostriches.
Also the one I remember best: Iraqi Corporation: You have no cows. Everyone thinks you have lots of cows. You tell them you don't, but they bomb your country anyway. You still have no cows, but now you have democracy.