interjection
that was delicious
Jocular interjection used as a pun on うまかった (past form of うまい, 'delicious'). The kanji 牛負けた literally means 'the cow lost', creating a humorous ateji wordplay. Not a standard expression; used playfully among friends or in casual online contexts.
See also: うまい
このラーメン、牛負けた!
This ramen was delicious! (pun on うまかった)
「牛負けた」って書いてあるけど、要するに「うまかった」ってことだよね。
It says 'ushi maketa', but basically it means 'umakatta' (it was delicious), right?