Many issues in bird nutrition are surrounded by myths and misunderstanding. Malcolm Green of The Birdcare Company attempts to shed some light on the important factors
for bird keepers. This is one of a series of articles covering a variety of nutritional topics.
Calcium, or much more often a lack of it, causes more problems in bird keeping than any other nutrient. Yet
most of people still believe that cuttlefish bone is a great source of this mineral. The reason for this is that many people still do not recognise the symptoms of calcium deficiency in their birds. This article will
address the extent of the problem, the symptoms and the solutions.
The only properly conducted study I know of was carried out in the late 1990s by Laurie Hess and her co-workers in New York. They studied 135 pet
parrots and carefully analysed their food intake. Here are the figures describing the percentage of birds studied consuming less than the recommended level of a variety of nutrients:
Since vitamin D is involved in calcium absorption and management it is hardly surprising that we see so many problems related to this mineral. An interesting aside on these figures is that about half of these birds
were being fed pelleted diets. So about 96% of the birds being fed pellets were not getting enough to ensure their calcium requirements were met. This simply highlights that owners dilute pellets in the diet with more
palatable seeds, fresh foods and human foods. And the fundamentals of the diet suffers!
Many breeders will be thinking that they have no problems because their birds have ad lib access to cuttlebone or they get oyster
shell grit or crushed egg shells or chicken bones. They would be wrong! All of these things contain large quantities of calcium but the calcium is very difficult to extract. All the animals making these things use
calcium for bone or shell because it is very difficult to dissolve. If bones were a good source of calcium owls would not waste it by expelling them in their pellets!
Very few wild birds get their calcium from mineral
sources like these. Instead they eat green sappy seeds or other vegetable products that contain calcium in forms that are far easier to absorb. Unfortunately dry seeds are not a good source of such 'chelates' of calcium.
Modern liquid calcium products mimic this natural approach. Firstly the calcium is already dissolved – very difficult with limestone or cuttlebone. Secondly the calcium is linked to a molecule the gut actually
absorbs naturally – most commonly a sugar molecule. The calcium is absorbed along with the sugar. This was discussed in more detail in the article in this series called 'Understanding bio-availability'.
Because these
modern products have such good bio-availability the quantities of calcium the bird actually eats is far less than the normal 'recommended daily dose'. But they work spectacularly well. In fact the way we use these
products most effectively is to give them less frequently rather than just in smaller quantities. For most birds once a week is fine. For eclectus and grey parrots we recommend twice a week and for breeding birds we
suggest up to five days a week. I will return to this later but for now I would like to discuss the symptoms of calcium deficiency.
Symptoms
Breeding birds tend to show the most obvious symptoms and I will
deal with them first. But the problems in pet birds can be more subtle but very distressing.
One of the most obvious signs of calcium deficiency is a soft shelled or thin shelled egg. Eggs with a chalky texture are
also included in this category. It is amazing how common these issues are, how obvious the relationship with calcium is and yet how many breeders still refuse to acknowledge the failure of cuttlebone and other
traditional supplements. According to the scientists in Hanover (Germany) a canary has about 3.5 eggs worth of calcium stored in her bones. So, if you want bigger clutches, you need a good quality supplement. Highly
productive birds like zebra finches can see clutches increase from 5-6 up to 9-12 without stress on the hen! These are dramatic increases in production.
Hens that are struggling to make egg shells very often get
egg-bound. In this case the bones have failed to provide enough calcium for the egg so the hen has 'stolen' it from other organs. When the nerves and muscles run low on calcium they stop working properly. These hens
simply cannot push the egg out. They tend to show other symptoms of poor nerve and muscle function too. They can't fly well, their wings droop and their legs are apart.
Traditional remedies include warmth (good),
oiling the vent (a waste of time and very stressful) and holding the bird over a steaming kettle (positively horrifying). Giving a liquid calcium supplement directly to the beak is far more likely to work very quickly.
Of course using the supplement routinely should prevent the problem in the first place.
The third common breeding problem is splayed legs and/or rickets in chicks. With splayed legs the issue is lack of nerve and
muscle function preventing the chick from holding the legs together under the body. It is not hens sitting too tightly! Correcting this problem requires constant adjustments to splints. Again prevention is a far better
approach!
Rickets is soft and bent bones. Splinting and/or surgery is required. Prevent!
In non-breeding birds we see both physical and behavioural problems. Because calcium is involved in nerve function a lack of
it leads to many nervous symptoms. Fear and aggression are both common. I once a had a zebra finch breeder who rang very concerned that his show team was being driven mad by our vitamin supplement. Whenever he entered
the bird room his show team flew around in a panic. The rest of his birds were not getting the vitamins and they seemed normal. Reluctantly he took our advice and continued with the vitamins but also included calcium.
The result was fit and clam show birds. The rest of the flock were also calcium deficient but their lack of vitality (from vitamin deficiency) meant they were too zombified to be able to exhibit the signs!
In pet
birds these behavioural issues vary from fear, biting (and other aggressive behaviour) to self-mutilation. It is our belief that all plucking birds should be given extra calcium. I find myself very sceptical of the
'normal' ranges for calcium quoted by veterinary laboratories. Given that 98% of birds are likely to be getting less than adequate calcium levels in their diets and most birds that are blood tested are ill I feel the
ranges they publish are very misleading. Our experience is that plenty of birds whose tests are in the 'normal' range respond very positively to good calcium supplementation.
Other pet (non breeding) bird symptoms are
poor co-ordination, flying and perching. It is quite common for pet African greys to fall off their perch in the middle of the night when they lose the ability to grip properly. Often these birds have trouble landing
even in familiar surroundings. Extreme cases lead to fits that are often incorrectly diagnosed as epilepsy. Parrots often make a clenched fist during these attacks, finches and canaries may end up on their backs and
twirl. Budgerigars simply have difficulty getting themselves off the ground!
How much and how often?
Poor calcium sources like cuttlebone and grit can be given every day ad lib. When birds are eating these
unappetising things they are telling you they are not getting enough proper supplement. These products can be a good indicator.
There are a lot of different factors that affect the amount of supplemental calcium your
birds may need. Obviously egg laying hens and growing chicks have higher requirements. Different foods have different levels and absorbability of calcium (all seeds are poor). Tap water around the country can vary
dramatically in their water content. And if you filter your water you are removing virtually all the suspended calcium it contains. So people in soft water areas use far more supplement than those in hard water areas.
This is why we recommend a range of application rates on our labels.
It is also why we recommend not giving it every day. If we are inadvertently giving more than necessary then the bird has days when it can easily
excrete the excess.
It helps to understand a little about how the body manages calcium in the body. The bones have the important role of controlling the blood calcium level. When blood calcium levels rise the bones
suck it out. When it drops they pump it back in. This sounds simple but it is actually quite a complex process involving vitamin D and a hormone called parathyroid hormone. This process works best if it is well
exercised. Giving the calcium supplement some days and not others ensures the bones have lots of practice at this job and they respond very well to the surges in demand from egg laying. This is all part of the process
of preventing egg-binding.
Our general recommendation is to give the supplement just once a week to non-breeding birds - twice a week for eclectus and African greys and for some people in soft water areas. For
breeders the norm is five days a week. People in hard water areas may do fine with just 2-4 days.
In the food or the water?
There is a small but vocal group of bird keepers who seem to see supplementation as
some sort of a threat to their manhood. They seem to delight in pouring scorn onto products they have never even used and certainly don't understand. These people are responsible for a great deal of mis-information and
they always seem to assume that because these modern supplements are liquids they must go in the water. This is rubbish! Liquid calcium can go in the food or the water.
As a general rule on-food supplementation is
preferred. It is generally far cheaper (people tend to be more wasteful with water than food). It is normally more reliable too as birds that eat a lot of fresh fruits and vegetables drink very little. Ring The Birdcare
Company if you need any advice on this.
Summary
There is no doubt in my mind that the introduction of highly bio-available liquid calcium supplements has been the most important bird keeping innovation for
decades. It has revolutionised breeding by increasing clutch sizes and maintained hen health so they can safely produce more rounds each year.
In pet birds the behavioural benefits are now beginning to be recognised
as people realise that so many intractable problems are actually calcium related.
Birdcare Company product table
