FINCHforum

I was reading this article about full spectrum lighting and the importance of it. This article states that full spectrum lighting doesn't have the required intensity, and even the ultraviolet fluorescent tubes, called black lights in the lighting industry, do not emit the intensity necessary for vitamin D3 synthesis. Thus, unless the birds maintained indoors have either an hour or so a day under sunlamp radiation, or a vitamin D3 supplement in their diet, or animal products as food to provide this vitamin, they are likely to have a serious vitamin D deficiency, leading to weak bones, thin-shelled eggs, soft-shelled eggs, and other problems with calcium metabolism.
Another proven way in which ultraviolet light affects our birds is in the sex of the offspring of our breeding efforts. The long wavelength ultraviolet seems to be the primary factor in this influence.
"In my own breeding, I was getting from 75% to 90% males while breeding these finches under artificial lights indoors. After reading about the effects of ultraviolet light in increasing the production of female offspring in animal experiments, I installed one four foot black light tube in my birdroom, placed so that it would shine directly into all of the cages.
This one simple change was sufficient to restore a normal 50/50 sex ratio to the offspring of all of the species."

I find this interesting because I'm getting too many hens and I only have full spectrum light.

Interesting that you notice the discrepancy in the number of male and female chicks as I never had this problem. It could be that all my cages get some direct sunlight everyday. I am also an avid fan of vitamins for my birds and have them on vitamins 3 times a week.

Chris

atarasi wrote:I find this interesting because I'm getting too many hens and I only have full spectrum light.

I also would like to get more male offspring. I had 2 full spectrum lighting tubes over the cage that is giving me mostly females. I just changed to 1 normal flourescent tube after someone suggested that to me for reducing the amount of UV slightly and hopefully restore balance to the offspring genders. Will note what happens in the nest few clutches and let you know.

I was considering getting a black light but that would (according the the article) increase the amount of female offspring.

Liz, too many hens isn't a bad thing! Most of the local breeders I know, generally have too many cocks and not enough hens. Some breeders actually charge a little more for hens because of it, plus the normal fatality rate because of egg binding.

atarasi wrote:Liz, too many hens isn't a bad thing! Most of the local breeders I know, generally have too many cocks and not enough hens. Some breeders actually charge a little more for hens because of it, plus the normal fatality rate because of egg binding.

Yep I know hens are good but I'd really like to be able to make a few unrelated pairs and need a few more cocks for that. If it were 60/40 for females - I'd be rather than 85/15

Quite a few breeders around the GTA charge more if you buy single hens instead of a m/f pair too. But I don't... yet.