A Joke?

SantaBanta.com originated this joke - "What is the difference between a Sardar (Sikh) and a donkey? Answer: a tail."

Does the above have any kind of joke sense? The heights of it is this is published by Reliance mobile to its subscribers as joke of the day (One97 is the provider of such jokes). I'm not a sikh & I have read Sardarji jokes just like Blonde jokes. But I don't really see the above as funny at all. In fact it just irks me & makes me uncomfortable.

Businesses directly reaching customers should have all public sense not to affect their sentiments in any way and especially not to touch them religiously or racially...