For those of us living north of the equator, late Fall through Mid Winter is the time of year when the nights are the longest and the days are the shortest. The further away you live from the equator, the longer the nights will be and the shorter the days. Also, the angle or height of the sun above the horizon will be lower. Now, believe it or not, the position of the sun plays an important role in the health of our birds, but I will get to that subject later in this article.
Every year I hear from fanciers that are experiencing the same problems; some of their hens that are unable to walk after laying their eggs, or they are showing signs or lameness or other mobility problems. Some complain that the egg shells are thin or rough or misformed in some way. Almost always, the suggested course of action throughout the sport is to supplement with calcium to correct these problems. However, I think the situation needs to be addressed months before it becomes a problem.
I believe, it is a management problem inadvertently brought on by the fancier. Though calcium supplementation, always seems to bring the quickest turn around to these problems with the hens, I suspect that the culprit is more often then not, a long term deficiency in Vitamin D (more specifically Vitamin D3).
The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. By promoting calcium absorption, vitamin D helps to form and maintain strong bones, and for birds strong egg shells. Vitamin D also works in concert with a number of other vitamins, minerals, and hormones to promote bone and egg shell mineralization. Without vitamin D, bones (and egg shells) can become thin, brittle, or misshapen.
Vitamin D requires chemical conversion in the liver and kidney to form dihydroxyvitamin D, the physiologically active form of vitamin D. Active vitamin D functions as a hormone because it sends a message to the intestines to increase the absorption of calcium and phosphorus. If our birds lack sufficient quantities of active vitamin D, then calcium and phosphorus absorption is limited and egg shell / bone structures may become thin, brittle or misshapened.
Additionally, research suggests that vitamin D helps fight off respiratory problems and supports a healthy immune system. Also, vitamin D helps regulate cell growth and differentiation (the process that determines what a cell is to become), two vital functions our birds need during the breeding season when they are fertilizing and creating the egg yolk and egg white that sustains the baby chicks until hatching.
So here is my management tip: Allow your birds to get some direct sunlight, if possible every mild day, during the winter months. Realize that UV rays from the sun trigger vitamin D synthesis. The Season, geographic latitude, time of day, and cloud cover affect UV ray exposure and vitamin D synthesis. Complete cloud cover halves the energy of UV rays, and shade reduces it by 60%. Glass windows can filter out the specific UV wavelengths that contribute to vitamin D synthesis, therefore, direct sunlight is needed in order to get the specific UV rays which trigger vitamin D synthesis. That is important to note, there are only specific wave lengths of UV light that will stimulate vitamin D syntheses. Not all hours of the day or cloud cover / clear sky contribute equally to Vitamin D synthesis.
Studies show that fanciers living in New England, the Great Lakes area, Upper Plains and Pacific Northwest, often get insufficient sunlight exposure from November through February to synthesize significant vitamin D, depending on the amount and quality of the sunlight their birds are exposed to, during the day. Certainly if your breeding loft does not have a southerly exposure you may well need vitamin D supplementation in preparation for the breeding season.
Please, do not do what many fanciers are guilty of doing and that is, to assume that if some supplementation is good, than a lot more supplementation is better. To much vitamin D can cause to much calcium to be absorbed and this creates its own problems, though to much calcium is much less a long term problem for our birds than to little vitamin D, our goal is to have healthy birds without to much or to little of any need supplement.
Several years ago, I built a breeding loft that faced to the south. It has solid walls on all sides with a small window on the east wall, and the floor was expanded steel grating. The roof was made of UV protected white translucent polycarbonate sheets. There was considerable light coming through the roof panels and the birds seemed to enjoy the loft very much. However, we could discern that there was something wrong with the living space, but we did not know just what it was, only a feeling that the birds were off a little. Our first clue was that the birds did not go down on eggs when they should have. They just were not building nest. My friend told me the birds needed direct sunlight and I built an aviary on the south side of the loft and the birds immediately started to build their nest and lay eggs. It wasn't enough that there was sunlight passing through the roof panels, the birds needed UV light which the roof panels filtered out. Direct sunlight seemed to do the trick, and the birds went right down on eggs.
I have recently learned that UV light is within the visible spectrum for racing pigeons. This is unlike humans who cannot see the UV spectrum in visible light without the help of a "Black Light" or other source of UV. I also read in Science magazine that certain animals and insects which see in the UV spectrum, are able to see marking on the opposite sex that stimulate mating behaviors. Theses markings that are only visible in the presence of UV light. During winter, the sun is to low on the horizon and the UV spectrum is filtered out, and so the opposite sex is not stimulated by these markings. But when spring arrives, the sun is now higher on the horizon and the UV light reflects off the pigeons stimulating mating behavior.
With the presence of UV light, the birds are displaying color and markings that signals the opposite sex into courtship mode. There is just the right amount of UV light in natural sunlight most of the year, but little in Winter. However, do not go and put UV lighting in your loft, as over exposure to UV light can harm the eyes. I wish they had told that to me before the "Black Light" craze, Oh well!
By the way, Max Immune Plus, Show Stopper and Bio-fresh products, all contain natural sources of vitamin D3, calcium and other minerals. Just one more reason to try our products for the good of your birds. You can visit my products page here for more info on my products and how the help your birds without the need for medications or antibiotics.