Popular cow riddles are:
   
“What do you call a cow with no legs?”/“Ground beef.”
“What do you call a cow with two legs?”/“Your mom.”
“What do you call a cow with two/three legs?”/“Lean beef.”
“What do you call a cow with three legs?”/“Tri-tip.”
“What do you call a cow with five legs?”/“Rare.”
 
“What do you call a cow with one leg?”/“Steak” has been cited in print since at least 2007.
 
       
Straight Dope Message Board
Do you know any jokes for 7-10 year olds? 
Tenebras
10-15-2007, 01:55 AM
Forgive me if these have been told before. . .
 
What do you call a cow with no legs?
Ground beef
 
What did the snail say when he rode on the turtle’s back?
(throw your arms in the air and yell) WHEEEE!
 
What do you call a cow with one leg?
Steak.
 
What do you call a cow with two legs?
Lean beef.
 
What do you call a cow with three legs?
Tri-tip.
 
Twitter
angie‏
@babyvtec
JOTD 12.21.09 - Brad: What do you call a cow with one leg? A: Steak!! #fb
1:13 PM - 21 Dec 2009
 
Twitter
Ness‏
@NessaBoxX
What do you call a cow with one leg…HAHAHAHA !!!
STEAK! hahahaha
2:29 PM - 8 Mar 2010
 
Twitter
DOSETRADAMUS‏
@BrandonAMF
Tony, what do you call a cow with one leg? Steak. Two Legs? Lean beef. Three? Tri-Tip. Four? Cow.
12:33 PM - 10 Aug 2010
 
Twitter
alisabelly‏
@alisabelly
what do you call a cow that has 3 legs? lean beef
2 legs? side of beef
1 leg? steak
no legs? Ground beef
thank you very much.
10:53 PM - 13 Aug 2011
 
Facebook
Certified Angus Beef ® brand
June 20, 2012 ·
What do you call a cow without legs? Ground beef
What do you call a cow with one leg? Steak
What do you call a cow with two legs? Lean beef
What do you call a cow with three legs? Tri-tip
What do you call a cow with FIVE legs? Rare.
 
Special thanks to our new intern, Malorie, for today’s comedy routine!
 
Reddit—Jokes
What do you call a cow with three legs?
submitted May 30, 2013 by hitokirivader
Tri-tip.
What do you call a cow with two legs?
Lean beef.
What do you call a cow with one leg?
Steak.
What do you call a cow with no legs?
Ground beef.
 
Reddit—TipOfMyTongue
What do you call a cow with 4 legs? (self.tipofmytongue)
submitted February 28, 2017 by georgecena1337
Alright so there are 4 parts to this joke:
What do you call a cow with 4 legs? (A cow)
What do you call a cow with 3 legs? (Tri-tip)
What do you call a cow with 2 legs? (This one has 2 answers: lean meat OR your mom)
What do you call a cow with 1 leg? (Steak/stake)
What do you call a cow with no legs? (Ground beef)
But I could have sworn that the cow with 4 legs had a better/second answer that wasn’t just “A cow” and it was way more funny.
   
Twitter
Painful Puns‏
@PainfulPunz
Q. What do you call a cow with one leg?
A. Steak
10:32 PM - 28 May 2017