I consulted my Avian Vet on using FS lights in the birdroom and Dr Linda Stern does recommend them for trying to discourage breeding and for helping the birds see their UV vision, but not for encouraging skin production of Vit D3. Dr Stern said my birds get Vit D3 from their Harrisons pellets, so they do not need Vit D production. I have found that keeping my birds on FS lighting on a 12 hr year round schedule does discourage most of my birds from breeding. One or two hens will break through and produce eggs every year, but not ALL of them like it used to be. I lovebird is the only bird who breeds each and every year; one of the cockatiels will lay, usually, but not often, and the budgies are all cocks. My single hen canary has not produced eggs in the two years I have had her; which is fine for me.
I also asked Dr Sherman who works at Good Hope Animal Hosp., and he said if what I am doing is working for keeping my hens from breeding, continue to do what I am doing. FS bulbs, he felt, don't harm the birds since they are ambient light, positioned one on each wall and not concentrated over each cage like some people do. So, I will continue as I have unless I hear some really pointed, statistically realistic reasons not to use FS bulbs.