The Importance of Calcium



By Susanne Russo


We have all heard that it is important to supply calcium sources, especially when a bird is laying or breeding. The reason why is to provide enough calcium intake to produce a strong, dense shell on the eggs. And to also be a preventative to soft or shelless eggs, which can contribute to egg binding and/or dystocia, impaction or prolapse of the uterus or oviduct.




The most common recommendation is supplying cuttlebone or calcium supplements, and greens or veggies that are rich in calcium. In supplying this we think the bases are covered and aid as a preventative to reproductive problems. Yet have a hen that passes a soft-shelled egg, prolapse or is egg-bound…why?




Most times this is not enough. Several factors can influence the output of calcium circulating in the bloodstream. The calcium is then drawn from the bones while an egg is in the uterus (shell gland). 




1…Researching the sources of calcium and other mineral nutrients is very important. High levels of phosphorus in the blood will inhibit the mobilization of calcium from bone. When this occurs this increases the chances of soft-shelled eggs which can lead to impactions and binding.




You can go online to look up on this site which foods (Nutrient lists) are high calcium:




Trace Mineral Dust is an excellent supplement that can be sprinkled on greens/veggie or in a separate dish to supply the nutrients needed for egg laying:  Below is a listing of what a shell consists of.




Calcium carbonate: 94-97%
Phosphorus: 0.3%
Magnesium: 0.2%
Sodium, Potassium, Manganese, Iron and Copper: traces
Organic matter: 2%




The small amount of organic matter mostly consists of matrix proteins (mixture of proteins and polysaccharides rich in sulphated molecules) and shell pigment. The matrix proteins are critically important in determining the eggshell structure and serves as foundation for the deposition of calcium carbonate.




The structure of an eggshell when examined under a high-powered microscope will look like a tangled network of mineralized fibers, kind of like looking at the mat in an air conditioner filter. The eggshell is formed around this mat of proteins, which is coated and overgrown by calcium carbonate and other mineral salts. The result is a tough, waterproof package that still allows gas exchange between the inside and the outside, enabling the developing embryo to ‘breath’, while providing astonishing mechanical strength. The shell has enough calcium carbonate in it. As the embryo gets close to hatch, it can use this reserve to draw calcium into the body and bloodstream for the developing bones.




NOTE: Most greens and veggies contain oxalic acids. These will bind useable calcium from food in the intestinal tract. What you want to do is look for foods that have a higher calcium content than oxalic acid. The useable calcium is the difference between the two. Print out the following tables from both links:
Guinea Lynx ::Oxalic Acid in Selected Vegetables
Guinea Lynx :: Calcium Chart


Once you print out the 2 links above, you will have to look at the listed calcium level in this link:  Deduct the oxalic acid levels to give you a clearer pix of the calcium to phosphorus (Ca:P) ratios. The calcium to phosphorus ratio should be 2:1. This chart shows calcium to phosphorus ratios:




USDA also has this chart on foods with oxalic acid:






2…Proper lighting plays an important role in good reproductive health of hens. Either available in the form of real sunlight (not filtered thru glass) or from Full Spectrum Lighting (FSL)  In simple terms the skin absorbs the UV (ultra violet) rays from the lighting and the body converts it to useable D3, and this in turn aids the uptake of useable calcium. 




The reason why either access to real sunlight (not filtered thru a window) or Full Spectrum Lighting (FSL) is important is that is that birds absorb the light into their skin. The body converts it to vitamin D3, also known as cholecalciferol. D3 is required in the intestines to help absorb calcium to regulate important blood calcium levels such as the hen is forming the shell in the uterus. Calcium is then drawn from the bones via the blood stream to the uterus (shell gland).

Some Cautions: This form (sunlight or FSL) of vitamin D3 is far safer than supplementing with vitamin D3. Vitamin D3 is a fat-soluble vitamin, which gets stored in the body, and if supplementing in excess this can create a toxicity. It can also contribute to hypercalcemia (too much calcium in the blood) which affects the heart, other organs and contributes to liver toxicosis, calcification of the kidneys and gout.




Therefore when feeding pellets, (they do contain D3 and calcium) you should never give additional supplements that contain (D3) and calcium because the diet is designed to provide what the bird needs.




If feeding a varied diet consisting of pellets (approx 20%) , seed, and fresh greens/veggies then it is safe to provide a calcium source, such as cuttlebone and/or mineral block. FSL and sunlight access are natural forms of sources for D3 and are safer and more easily assimilated than from artificial sources.






3…Preventative water treatments such as ACV (Apple Cider Vinegar) can change the pH in the digestive tract. When the pH is higher than 6.5, absorption of phosphorus markedly decreases. Nutrient absorption occurs through the tiny veins in the digestive tract. If the pH is changed, this in turn contributes to the blood being alkaline and the availability of calcium is in turn reduced. The disturbance of the acid-base balance in the blood results in an increase of soft-shelled eggs, shelless, and rough shelled eggs. If the integrity of the shell has been compromised, this in turn can affect hatchability. 




Excess free fatty acids in the diet can cause the pH to decrease and therefore, interfere with calcium and phosphorus absorption. In summary, if the intestinal flora and pH is altered this can cause several problems. If preventative treatments are used it is better to find the cause and correct it.






4…The time of day that a hen lays an egg is also good to know…..




A…If a hen lays during the afternoon or early evening providing higher calcium levels in the gut during this time is important to ensure calcium is being taken from the diet and not bone. 




B…Hens that lay in the mornings are at more risk of calcium depletion because food intake and absorption of nutrients/calcium is decreased. Therefore, the body has to draw from the bones. If the bones do not have an adequate store of calcium in the marrow this results in hollow bones which can break or fracture. The most common bones that can be affected are the wings and legs. With the legs, depleted bones will be soft and bow. With wings, as the bird tries to fly the bone may break, and if not noticed right away the bone will knit back together misaligned causing the wings to permanently droop.




Calcium has to be supplied and maintained in the blood levels. Calcium is drawn through the marrow of the bone, which is called Bone Calcium. It is also in the intestines for good utilization while laying. If blood calcium levels are low there is going to be insufficient calcium for shell formation. The bio-available levels can be depleted between 8-18 minutes during the time the egg is in the uterus. 




During the last 15 hours of shell formation (when the egg is in the uterus, also called a shell gland), calcium movement across the shell gland reaches a rate of 100-150 mg/hr. This process draws calcium from two sources: diet and bone. Intestinal absorption of calcium in the diet is about 40% when the shell gland is inactive, but reaches 72% when active. This time closely coincides with late afternoon or the dark hours for the laying hen.




5…NOTE: We are warned not to provide sources of sodium to our birds, but many can go to the extremes of eliminating all sources of sodium and this can have an negative effect on a laying hen. The lack of (or deficiency) trace minerals and salt can be contributing factors to soft shelled eggs, and poor uterine muscle tone. This is also true of many birds that die of egg binding. Salt/sodium aids in the muscle contractions. When there is a deficiency there can be a loss of muscle tone to expel the egg. Therefore, in researching on a diet supplying needed calcium, and other trace minerals, try to include sources of sodium.




6…Weigh the hen prior to setting up….When you setup your pair it would be helpful to know the weight of the hen. During ovulation the hen will gain apex. 5-6 grams of weight as the egg travels down the oviduct. If the hen is showing obvious signs of wanting to lay (hunched back, lowered tail, wide stance, swollen abdomen) and no egg is seen after several days of the visible signs, handle her carefully and weigh her. If the weight has increased 10 grams or more it could be an alert to some problems going on inside the reproductive tract.




Scales that weigh in grams are very helpful. You can look at an office supply or go online to search/purchase a scale. Below are some links to some scales available at 




A basic scales that weighs in grams: 




Or Walmart has a nice inexpensive scales:






Specialty scales that weigh in increments of grams are also useful. Below are a couple of links. These type of scales can be used for monitoring the weight of eggs or monitoring the weights on babies that are being handfed from day one. For example the average weight of a freshly laid egg is 5-6 grams. As the egg gets closer to hatch it can lose up to 16% in weight. Some of this weight loss is a reduction of fluids that the chick uses for nutrients and loss of shell density as the chick draws in calcium from the sell. If the weight loss is up to 20% and the air cell is taking up a lot of space this is an indication that the egg is losing too much moisture. This can result in the membrane sticking to the chick and preventing it from hatching. In this situation the chick may have to be assist hatched:




When monitoring a tiny chick it may be hard to tell if there is any slight gain or loss if the scales weighs in grams. 




Scales that weigh in increments of .001 grams:




Scales that weigh in .01 grams:




Some problems that can occur during ovulation are:




This is an article I am working on that has some helpful info:

Ectopic ovulation is occurs when the infundibulum fails to engulf the yolk (ovian) because of reverse peristalsis of the oviduct, trauma or stress. The yolk misses the funnel of the infundibulum and goes into the abdominal cavity.




If the egg moves too fast (don’t know the causes of this) then it does not pick up the yolk but the other steps are done in the uterus it will result in an egg with no yolk. An egg with no yolk will not hatch.

Oviductal diseases that may result from Ectopic ovulation may include infectious salpingitis, rupture of the oviduct, cystic hyperplasia, peritonitis.

Egg yolk peritonitis is most common with cockatiels, budgies, lovebirds, ducks and macaws. Clinical signs include weight loss, depression, respiratory distress, anorexia, and ascites. Abdominal distension may or may not be present.




7…Examining and providing the best sources of calcium does not stop at providing good shell quality. 




Hypocalcemia, and Seizures


When keeping and breeding we focus on supplying proper lighting and calcium sources to the hen. The above is just as important to a male. If lacking, the bird would have problems assimilating calcium and a lack of compensatory mechanisms to maintain serum calcium levels, and an inability to mobilize skeletal calcium. Sometimes this can also appear as a vitamin D3 deficiency.  When this happens the bird is very prone to having seizures.




A…Hypocalcemia and seizure activity tends to be a problem only with male cockatiels.

Treatment for hypocalcemia consists of calcium (injectable calcium with phosphorus at time of seizure), D3 (preferably exposure to sunlight or full spectrum lighting)  and supportive care such as Sub-Q fluids, which will get the blood levels up, and multivitamin injections (must contain Vitamin A and E)



Another thought at the time for seizures was a malabsorption problem. I found this is partially true. Most greens contain oxalic acid. I didn’t know this at the time except for spinach which with the calcium and reactions to oxalic acids form calcium oxalates. Stress causes a sudden increased acidity in the GI tract and also upsets the metabolic balance of fluids in the body. Everything is a chain reaction.




I had some birds that had to have a health inspection. One had a seizure in the vets office. He drew blood to have sent out to a lab. I told him to give a Calphosan shot (calcium and phosphorus) because it had worked in the past for me to bring a bird out of it. At the time I had thought it to be a malabsorption problem. Blood calcium and phosphorus levels were real low. Similar to what is seen with African Greys which are also prone to hypocalcemia.




At the time I did not know what exactly was the cause. In reality simple capture increases the heart rate that can trigger a hypocalcemic bird into a seizure because there is not enough calcium in the bloodstream. Some mutations such a cinnamon, fallow and lutino, or splits to these mutations tend to have this problem. Heart rate is increased when trying to get a bird out of the cage, or chasing and netting. But if blood was drawn while the bird has a seizure it would show very low blood levels. The quickest way to bring it out of seizure is injectable Calphosan. or orally with a drop of liquid calcium under the tongue. The injectable calcium rapidly gets the blood calcium levels up.




In regards to your birds many greens are rich in calcium and phosphorus.  Researching the nutrient content of foods (1…) is just important to the male.




B…The need for a good source of calcium does not stop at supplying it prior to egg laying. The calcium is drawn into the developing embryo as it grows through the vascular network of blood veins radiating into the body from the yolk. During this time the embryo draws calcium from the shell to strengthen developing bones. If the calcium in the shell is insufficient this can contribute to weaker bones, and problems such as splayed leg, soft flexible leg bones, and/or fractures forming within days after hatch. For good bone growth and strength, these post hatch problems can be avoided by supplying food sources rich in calcium and trace minerals to the feeding parents.



C…Examine any eggs when they are laid. Ideally, what you want to see is a uniform color and smoothness to the shell. If there is any swirling to the shell that looks like alternating bands of pinkish and white this is an indication that not enough calcium was in the body as the shell was being formed. The pale areas of the shell are weaker and can be sources of moisture loss as the developing embryo grows. After piping the chick will draw from the calcium reserves of the shell. If there is insufficient calcium this can be seen by soft areas of the shell collapsing inwards and appearing like large dents. If the shell is compromised and fluid is lost this can also result with a chick trapped in the shell which in turn can cause death if not assisted from the egg. These chicks would also be prone to splayed leg developing early in the nest, or compound fractures as the grow.




If there are deposits of calcium on the exterior of the egg, which appear as gritty lumps adhered to the egg this could be an indication that there might possibly be an infection in the uterus (shell gland)




Small eggs with no yolks




If you candle the small egg you will not see the yellow yolk in it. Many times if the egg is forming in the oviduct the contents of the egg (Region 2 in the Illus.) may have started to move downward in the oviduct before the yolk was dropped into Region 1 If this happens the egg is smaller and does not contain a yolk.

If there has been anything that has stressed the hen during the laying process, or she has not been handled, this may not be the problem. If so, there is a possibility the yolk could have missed entering the funnel in Region 1. If this happens then the yolk will get diverted into the abdominal cavity of the hen.

If you have a scales I would suggest that you weigh the hen now. If a hen is ovulating and prior to laying she will gain approx. 5-6 grams in weight. If there is a problem developing such as egg related peritonitis there would be approx. a 10 gram increase and each day the weight would increase up to 7-10 days as much as 20-30 grams. You do not want to see a weight gain past 6-7 grams prior to laying.




Never handle a hen if you suspect she is ovulating. It could contribute to the following:


1…An Ectopic egg, also called non-septic egg peritonitis, meaning that the yolk got diverted into the abdominal cavity, which can lead to peritonitis.


2…If the forming yolk was ruptured from the movement it could get absorbed into the bloodstream and cause a stroke and/or death.


3…If the egg was in the upper oviduct it could cause a tear in the thin tissue and get diverted to the abdominal cavity.


4…If the egg has gotten as far as the shell gland and the disturbance occurred when the shell was being formed it could have broken, but the shell part would be adhered to the uterus and the nest developing egg would impact on the matter in the oviduct. Several eggs can get impacted 1 on top of the other (broken soft shells stacked up) and contribute to egg-binding or prolapse. In this case the inside of the egg (yolk and white) would be seen on the cage/flight floor.




Having a night light or a low wattage bulb (25-40 watts) on during the night would be helpful and cut down on any panicking during the night. I have learned that when a hen is laying movement, handling, and disturbances need to be kept at a minimum.




Some Additional reading




Note: I got permission from the publisher to remix several of their illustrations. 




OVIDUCT of a Hen:  During active laying the oviduct enlarges and occupies much of the left abdomen. The oviduct in birds is divided into several parts:


  • ·         Infundibulum (formation of Chalazae, place of fertilization)
  • ·         Magnum (formation of egg white)
  • ·         Isthmus (formation of the shell membrane)
  • ·         Shell Gland (formation of egg shell)
  • ·         Vagina (formation of cuticula)




Female Bird Reproductive Anatomy:




Reproductive Problems (A very informative site)




Article on prolapse:




Endoscopic Salpingohysterectomy:




How I treat psittacine egg binding and chronic laying (What a vet will do):




Chronic Egg-laying in Single Cockatiels:




Why did my cockatiel lay an egg?


111 thoughts on “The Importance of Calcium”

  1. Greetings fom Colorado! I’m bored at work so I decided to browse your blog on my iphone during
    lunch break. I enjoy the info you present here and can’t wait to take a look when I get home.
    I’m surprised att how quick your blog loaded on my mobile
    .. I’m not even using WIFI, just 3G .. Anyhow, very goodd

    My web page :: motorhome rent (Mike)

  2. Now every guy wants that added inch when they are in their tuxedos especially to impress a friend or a colleague.
    Just like the minimalist road running shoes of 2013, these trail
    shoes will be lower to the ground at 6mm or less, lightweight, moderate cushioning, and some protection. When you’re going on a trip to polish your skills with a
    rifle, don’t forget to wear shooting socks.

  3. I just want to tell you that I am just very new to weblog and seriously loved this blog. Very likely I’m planning to bookmark your blog post . You amazingly come with wonderful articles. Thanks a lot for revealing your website.

  4. Was würde ich nicht geben, eine Debatte mit Ihnen zu diesem Thema haben. Du sagst einfach so viele Dinge, die aus dem Nichts zu kommen, die ziemlich sicher Id Im, haben eine faire Chance. Ihr Blog ist grandios visuell, ich meine Leute nicht langweilen werden. Aber andere, die an den Videos und dem Layout sehen gewohnt so beeindruckt sein zusammen mit Ihrer generischen Verständnis für dieses Thema.

  5. Now every guy wants that added inch when they
    are in their tuxedos especially to impress a friend or a colleague.

    Just like the minimalist road running shoes of 2013, these trail shoes will be lower to the
    ground at 6mm or less, lightweight, moderate cushioning, and some protection. Magnesium sulphate, in Epsom Salts, is a wonder mineral, in which many people are deficient.

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>