By Penny Corbett
I have a pair of breeding cockatiels laying oddly shaped eggs that are not soft, but not hard either. They are fed the best cockatiel mix available, and I change the water twice a day. I do not give them a cuttlebone because the person I bought them from, a very good breeder, told me it will cause the eggs to be to hard, and the chicks won't be able to hatch. They have never had babies since I got them. Can you help me?
The first order of business is to either close off or take down the nest box and shorten the length of day on this pair of cockatiels. They really need to be rested. In addition to a rest of at least six months, look at the complete diet they are on. It would help to consider the previous diet they were on, if you know it. Even though there can be several causes of abnormal eggs, the most common cause is nutritional.
When it comes to diet many people have their own opinion and practices. The one thing that almost everyone agrees on is that an all-seed diet is not the best diet for a bird. Birds being bred need even a more complete diet containing better nutrition than those kept as single birds or not used for breeding purposes.
Since your hen is on a seed-only diet and is not supplied with a calcium source, the diet needs to be examined. The eggs being laid by your hen are a very strong signal that there is a shortage of calcium. Birds on a seed-only diet are also normally deficient in vitamin A. Vitamin A deficiency has been associated with soft-shelled eggs, along with Vitamin D3 and calcium. This does not mean that these are the only deficiencies. These are just what seem to be obvious.
Birds fed a seed-only diet and not provided with a source for calcium will most likely be deficient in other vitamins and minerals as well. A few good calcium sources are cuttlebone, mineral blocks and hard-boiled eggs or boiled egg shells. Supplying extra calcium alone may not correct the problem or may do so only temporarily. All birds, especially those in a breeding program, should have the proper nutrition. The dietary needs of breeding birds are different than the maintenance diet of a companion bird. Breeder diets have an increase in protein and, usually, fat. Most diets also include an appropriate increase in the calcium-to-phosphorus ratio. The increase of important vitamins and minerals would also be included.
Necessities: Calcium And Protein
Calcium is needed for healthy egg production in breeding birds, and baby birds need it while growing and forming new bone. Adults require enough calcium to support bone structure, as well as other functions such as muscle and heart contractions. Calcium has other important functions as well. Calcium is a mineral, but it does not function alone. In order to be absorbed and metabolized properly, it must have the proper ratio of phosphorus and adequate amounts of vitamin D3.
It is also believed that growing chicks require higher protein levels than the breeding bird or hen. The growth period of a bird is the time in which the most nutrients are required. Depending on the species, it is particularly true for approximately the first eight weeks after hatching. The optimal requirements are still being studied, and there are most likely differences between species.
A word of caution: Except for the addition of a cuttlebone or mineral block, do not supplement birds on a pelleted diet, except under the strict supervision of an avian veterinarian. Doing so can lead to the overdosing of supplements or toxicity.
Even though most problems of this type are diet related, the parathyroid hormone is important in calcium regulation. Any and all thyroid dysfunction should be diagnosed by your vet.
Other Causes Of Abnormal Eggs
Nutrition and thyroid function are not the only possible cause of abnormal eggs. There are other medical conditions that could be the possible cause.Exposure to chemical toxins may cause abnormal eggs. This exposure may be from contaminated feed or other chemical uses such as spraying. There is a belief that abnormalities may be from residual activity of poisons and the long-term storage of chemicals in the body fat. Exhaust fumes and nicotine are two common environmental conditions to be aware of in the occurrence of abnormal egg production and weak or dead chicks.
Failure To Hatch
There can be several reasons that eggs fail to hatch successfully if they are fertile. Once again, nutrition plays an important role. Without the needed vitamins and minerals, the embryo will not be able to develop properly and may die at any time during incubation. A nutritionally deficient chick may develop to term, but not be strong enough to successfully hatch. Or it may die shortly after hatching because it wasn't strong enough to go through the hatching process and survive. The age of the embryo's death will usually depend on the type and severity of the deficiency involved.
Disruption in incubation is a common cause of a clutch failing to hatch. Inexperienced or poor breeding cockatiel pairs will leave the nest for extended periods during the day or even stay off the egg for the entire night.
Humidity is another important factor for egg hatching. Cockatiels, especially the hen, will take a bath and return to the nest. This bathing is normal and should not be discouraged. It is nature's way to increase humidity in the nest. If the humidity is too high or too low, the result can be death for the embryo. Incorrect humidity can cause embryo fatality at any stage of the incubating process. Chances are good that the failure for fertile eggs hatching with cockatiels lies within one or two areas: Either the eggs are not being incubated properly (inconsistent sitting or leaving the eggs for extended periods) or the humidity level is not correct. With pairs of cockatiels being bred indoors, it is more likely that the humidity level is too low because of artificial heating or air conditioning. An environment that is extremely damp from water leakage into the house or other similar factors, especially when the weather has been unusually rainy, may cause the humidity levels to be too high.
Breeding birds have the same guidelines as humans:
• Just because children are capable of having babies at a young age does not mean that they should. Their bodies are still growing and developing (maturing), the same as young birds are doing.
• We have been told time and time again that we are what we eat. The same is true of our birds.
The secret to our lives is the same for our birds: Great nutrition and exercise. Remember that the main reason for the problems seen by veterinarians are diet related.
Columnist Penny J. Corbett has been breeding birds for more than 25 years. She has experience showing and judging many species, including color-bred and type canaries, finches, and softbills. She currently breeds mainly hookbills.