As we previously reported ... Cutler had been dealing with an unknown menace that was ripping the heads off his beloved birds ... and he devoted his retirement life to saving his chickens.

The week-long saga took many twists and turns -- including traps and overnight stakeouts -- with pretty much the entire nation on the edge of its seat to figure out who the hell was offing the chickens.

But, Jay can now FINALLY get some sleep ... 'cause he's officially discovered the culprit -- A DAMN TRASH PANDA!!!

"All is well and happy to report it was a raccoon," Cutler said on IG Wednesday morning. "Which fits the evidence. Chicken heads were ripped off and bodies were left in the chicken yard."

"Gruesome stuff but the reality of the situation. Ladies are now safe and sound. We can all sleep well for a few nights."

So, is this the end of an era and we can all go back to worrying about bigger issues?? Yes ... at least, for now.

"Unfortunately I’m sure this raccoon has some family members."

"While this saga is sadly ending, I’m sure there will be more. Stay tuned..."