Well I think I figured it out all by myself and I feel pretty foolish. Back when I was waffling back and forth whether to breed or not I put three of my kitties on no breed so they wouldn't eat as much. I meant to do all four, but I messed up (which was fortunate for me or I never would have figured this out). Anyway, when I turned breed back on I didn't realize they would be on food recovery. I think someone mentioned it back when I was fudging around about breeding or not breeding, but I didn't pay very close attention... anyhow...
So I thought I'd move my kitties into the cattery to see if that would make any difference. I moved Feran first and I noticed he had this lovely star next to him... I thought, how nice, he's earned a star. I moved his mate, Pinto, into the cattery to join him and I saw that she didn't have a star. I said, hmmmm... I moused over the star and it said "in food recovery." AH-HA!!! I checked the vitamins, and sure enough, there's a food recovery vitamin. I gave it to him and I bought some for Purrsilla and Gio as well. They've already been dosed. Now we'll wait and see if they start feelin the luuurrrve.
Thanks for letting me blather on about this and I hope it helps someone else.
... and I'll be back if it didn't work