What is the minimum regard a meeroo can have and still breed?

I fell out of the habit of petting them very often. And while waiting and wondering why two pair had not yet bred, I noticed 3 of the meeroos were at 55% or uncomfortable (DUH!) I have just forgot about this minimum thing.

I've pet two of them up to happy, but what is the minimum percent or regard points for a meeroo before it will breed?

Please note, the couple in another thread that I mentioned as skipping a nest are not any of the above three. That other couple had regard into the thousands.

Thanks!