By Carol Heesen
As we move through the breeding season, there is increased discussion of the problem of egg binding. What is egg binding? Egg binding is the inability of a hen to pass a developed or partially developed egg. A partially developed egg can have either a soft shell or no shell. Many cases of egg binding occur when a hen is trying to pass what appears to be a "normal" egg. The inability to pass the egg quickly results in the death of the hen.
There are a multitude of theories as to what causes egg binding.
Many consider cool temperatures to be the deciding factor. I find this a very questionable theory. Birds in the wild often breed early in the spring while temperatures are still very cool and yet do not suffer from egg binding. I personally have Goulds successfully breeding in my outdoor flights when temperatures are down in the low to mid 40s. Despite raising hundreds of birds in cool conditions, I have not had a hen experience egg binding.
Another common theory is that the hen is too young. In parrots and budgies, where the bird continues to grow in size for 2 or more years, this may often be the case. The poor hen has just not grown sufficiently to allow the easy passage of the developed egg. Finches and canaries, however, grow and mature very quickly. Most have reached full adult size by the time they reach 4 months of age. In the wild, Goulds have often been observed raising chicks before they have even molted into their adult colors. I have observed this same phenomenon in my own flights when I have been a bit slow in separating my maturing juveniles.
Let me be quick to point out that I am not advocating breeding very young birds. The offspring of early breeding are not of the same quality as later breedings. It is best, I believe, to allow our birds to become older before attempting breeding. My point is only that early breeding does not, in my experience, result in egg binding.
Another common theory is that egg binding is the result of lack of calcium in the diet. Most of us offer a variety of calcium sources to our birds (egg shell, cuttlebone, oyster shell) and yet hens still die from egg binding.
I do believe nutrition is at the root of this problem. Most bird breeders are careful to offer a variety of calcium sources. Rather, I believe, the problem is the inability of the bird to metabolize the calcium that is readily available in the diet. The other major cause is poor condition of the mucus membranes in the vent area. Let's look at each of these issues separately.
Calcium is used by the body to not only form the shell of the developing egg and maintain strong bones, but is also crucial in the proper functioning of the muscles. While it does take a large amount of calcium to form an egg shell, the hen also needs calcium for the muscle action needed to expel the egg.
Vitamin d3 is crucial in the absorption of calcium. Without it, all that good calcium we offer our birds passes right through the body without being absorbed. In outdoor flights, our birds are able to produce d3 via a chemical reaction to sunlight. In indoor flights, they are unable to do this. Sunlight through a window is not sufficient. The ultraviolet light needed does not pass through window glass. Full spectrum lights can help but some studies have shown that the ultraviolet is only at sufficient levels at less than one foot from the light source. For inside birds, a d3 supplement is almost always helpful.
An excess of phosphorous, can also interfere with the absorption of calcium. According to Robert Black, plant materials (like all those wonderful seeds we feed our birds, contain an abundance of phosphorous. Animal products like egg foods, insect foods and mealworm, contain an abundance of calcium. By serving both plant and animal products to our birds, we are able to keep the calcium/phosphorous ratio in balance.
Some of those yummy greens we offer can also interfere with calcium absorption. Oxalic acid found in spinach, beet greens, chard and rhubarb reacts with the calcium so that it can not be absorbed. While these greens are rich in a number of nutrients, it is important to feed them in small amounts and provide extra calcium when doing so.
In order to pass a developed egg, the mucus membranes around the vent must be soft and flexible. It is the fat based vitamins that are primarily responsible for this condition, most notably linoleic acid (Vitamin F) and Vitamin A. Without these essential nutrients, the oviduct becomes dry and hard. Most avian vitamins do not include the fat based vitamins, so it is important to supply a separate source for these vital nutrients. These essential fatty vitamins can be found in many of the oily seeds such as safflower seed, sunflower seed, and niger seed. I have found niger seed the easiest for finches to accept.
If you do have a finch suffering from egg binding there are some things you can do.
Once the egg has passed, the bird will appear to have made a complete recovery. It is now time to assess the nutritional problems that caused this problem in the first place. It is dangerous to attempt to breed this hen again until the nutritional deficiencies have been addressed.
Carol Heesen has been breeding birds for 7 years. She works primarily with the Australian finches including the Peales Parrot finch and the black rumped owl finch. She also runs an avian supply business on the internet. She is a US reseller of VETAFARM PRODUCTS, Breeder of Australian Finches, and a Member of NFSS and Finchsave. You can view her site at http://www.birds2grow.com/ or call for a brochure at 209-869-5900.
Copyright © 1999 Carol Heesen. All rights reserved.
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