“Why did the cow cross the road?”/“To get to the udder side.”

“Why did the chicken cross the road?”/“To get to the other side” is a classic riddle from the 19th century. A cow version is:
 
Q: Why did the cow cross the road?
A: To get to the udder side.
 
The joke was printed in Newsday (Long Island, NY) in 1978, and has been printed on several images.
         
       
13 August 1978, Newsday (Long Island, NY), “Smiles,” Kidsday, pg. L11, col. 3:
Why did the cow cross the road?
To get to the udder side!
—Alisan Weiss, Hauppage
 
25 July 1992, Lancaster (OH) Eagle-Gazette, “Children get lesson in magic” by Molly O’Reilly, pg. 2, col. 3:
Dr. Eldoonie asked her, “Why did the cow cross the road?” His answer, “To get to the udder side.”
 
Google Books
Kids’ Funniest Jokes
Edited by Sheila Anne Barry
New York, NY: Sterling Publishing Company, Inc.
1993
Pg. 80:
Why did the cow cross the road?
To get to the udder side. IRENE RIESEN, 10
       
Google Books
The Usborne Book of Silly Jokes
By Lenard Le Rolland and Laura Howell
London, UK: Usborne
2003
Pg. 46:
Why did the cow cross the road?
To get to the udder side.
 
Twitter
weenick‏
@weenick
Why did the cow cross the road? To get to the udder side…Not gonna tweet more like these ‘cos I’m a little chicken and think they’re cheep
2:05 PM - 17 Apr 2009
     
YouTube
Jokes - Why did the cow cross the road? To get to the udder side.
jokesus
Published on Oct 5, 2015
Joke :
Why did the cow cross the road?
To get to the udder side.
   
Me.Me
WHY DID THE COW CROSS THE ROAD? TO GET TO THE UDDER SIDE @BLACK MINION MEME
POKEMON BLACK CROSS MINION THE ROAD COW SOURCE WHY DID ROAD SIDE GET JOKE APPROVE UDDER COWS MINIONATOR MINIOR DOES NOT APPROVE NOT THE JOKE THE DIDLY COWE BLACKNESS UDDERLY NOT APPROVE DOES NOT
FOUND ON 2017-04-23 18:15:38 BY ME.ME
SOURCE: ITEMS
 
Twitter
Gramercy‏
@GramercyCarmel
We are still celebrating #NationalTellaJokeDay! One of our winners submitted: Why did the cow cross the road?
To get to the UDDER side
11:24 AM - 17 Aug 2017