cow tipper

Are you trying to get leather from the cow, or the achievement itself? Getting leather from a cow is a small chance, usually around 0-2 leather per cow.

the achievement itself

The Cow Tipper achievement requires you to make a wooden sword first. Have you done that?

yes thats not the problem though

it says to kill a cow i killed a cow i need that achievement to work like its intended

Yes but you have to do all the achievements that lead up to it, or it won't unlock. I just tried it in 14w31a and it works fine.
Did you unlock Taking Inventory, Getting Wood, Benchmarking, and Time to Strike yet?

That is not the issue technically it is that I want the achievement to work with beef as well as leather but I think it's stupid that it's only leather I mean come ON this is called COW tipper not "get leather" I just want this achievement to be cow tipper not to just get learher

Ok it may not be a "bug" so to speak but it's a suggestion

Okay so you want to get the achievement by getting beef instead of leather. Good suggestion. Might be a solution to those complaining about MC-17298. But you'll have to post the suggestion to reddit.