In German, there are contractions, but they follow different rules.

In your example, you would not drop one of the consecutive vocals, but rather one fo the consecutive consonants. So "Wo ist das Rind(fleisch)?" would become "Wo is' das Rind(fleisch)?".

It would be acceptable in speaking, though quite uncommon in writing, to contract even more to "Wo's' das Rind?".

I'd like to note that "Wo is'n das Rind?", as proposed in the other answers, is not actually wrong, but it's a contraction of "Wo ist denn das Rind?" which was not used in the question like this and isn't an exact translation of "Where's the beef?" either.

In German, there are contractions, but they follow different rules.

In your example, you would not drop one of the consecutive vowels, but rather one of the consecutive consonants. So "Wo ist das Rind(fleisch)?" would become "Wo is' das Rind(fleisch)?".

It would be acceptable in speaking, though quite uncommon in writing, to contract even more to "Wo's' das Rind?".

I'd like to note that "Wo is'n das Rind?", as proposed in the other answers, is not actually wrong, but it's a contraction of "Wo ist denn das Rind?" which was not used in the question like this and isn't an exact translation of "Where's the beef?" either.