Avian Nutrition 101
Nutrition is the foundation for good health and efficient avian husbandry. Unfortunately there is a lot of misinformation on Psitticine nutrition, and what is available has been adapted from the poultry industry and influenced by the Parrot Food manufacturers. The American Pet Products Manufacturers Association (APPMA) reported in a 2001 survey that 6.9 million households in the United States have birds as pets. No wonder the Parrot food industry is so interested.
Commercially available parrot food ranges from seed/dried fruit mixes to processed pellets. On our Diet 101 page we discuss in detail the problems with commercial "parrot food" including the manufacturers that take seed and turn it into a pellet so consumers don't even realize it's the same garbage as what's in the seed mix. Why do they do it? Because it's cheap and birds love the fat. If birds love it, they will eat more of it and manufacturers will sell more. It's all about the money, meanwhile birds are getting sick and dying due to malnutrition, fatty liver disease, and renal failure.
Feeding well is an art form. In the wild birds are opportunistic omnivores, that is they eat anything available ... vegetable, animal material, soil and even mineral deposits. This diet is impossible to replicate in captivity and you wouldn't want to because captive birds don't have the energy requirements that their wild cousins do. Therefore, feeding captives like you would wild birds is not optimal nutrition; doing so will result in birds living short lives.
Let's look at the vital components of Avian Nutrition. (Click the items below to jump to a section.)
Okay, so it's not a nutrient as such, but it IS essential. Water is necessary for cooling the body and supporting the many functions that occur inside and outside cells such as digestion, food absorption, and for elimination of wastes.
Water source hygiene is essential and something many don't take seriously enough. Water is easily contaminated by food and feces. One touch of a food covered beak or poop covered foot and the water is contaminated. Bacteria starts to grow and they grow fast!
When bacteria grow, they increase in numbers not in size. This process is called cell division (or doubling). Under ideal conditions, the number of bacteria can double every 30 minutes. Therefore, one becomes two, two become four, four become eight, and so on. If you start with one bacterial cell, within 12 hours there would be as many as 33,000,000. The rate at which bacteria grow is different for each type or organism and is affected by many factors.
Water delivery systems (water bottle like a Bird Butler) are recommended to keep the water source bacteria free. Food bowls that contain chop and "wet foods" (>20% water content) should be washed at least daily with hot soapy water, rinsed thoroughly (twice a day is even better).
Amino Acids are the building blocks of proteins and make the DNA and RNA inside the cells. Proteins are made up of a combination of 22 Amino Acids, 10 of which can’t be manufactured by the body so they are deemed essential Amino Acids. Amino acids that are deemed to be essential for birds include arginine, isoleucine, leucine, lysine, methionine, phenylalanine, valine, tryptophan and threonine.
The usefulness of protein in the diet depends on its quality. Factors affecting quality are:
Balance - Optimum Proteins have a profile similar to that of the animal’s own proteins (i.e. in the correct proportions for use - no deficiencies or excesses).
Availability / Bioavailability - AAs may be present but can’t be used due to inhibitors that block absorption where the structure of the protein is such that it can’t be broken down or because of competition with other amino acids.
The dietary requirement for protein varies with age and physiological state. The ability to digest proteins is highest in nestlings and laying females, and lowest in adults at the maintenance phase of their lives. Excessively high protein is strongly correlated with a significant increase in liver lesions and excess protein has been associated with overgrowth of beaks and nails. A good way to get plant protein is to offer sprouted seeds.
Animals and birds have no specific requirements for fats, but they do require essential fatty acids that make up the fat. Linoleic acid is the most important; this fatty acid cannot be synthesised in the body and must be provided from food. Linoleic acid is required as 1% - 1.5% of diet.
Linoleic acid is an essential fatty acid that is an omega-6 fatty acid. Plant-based oils are good sources of linoleic acid for humans but you don't want to feed your parrot a lot of oils. This is why Tree Nuts are so important to your parrot's diet. Nuts provide linoleic acid. An ounce of Brazil nuts has 5.8 grams; an ounce of pecans, 6.4 grams; and an ounce of pine nuts, 9.4 grams. Nuts also provide dietary fiber, vitamin E and potassium.
There are two main groups of Vitamins; Fat soluble (A, D, and E) and Water soluble (all others). Click HERE for our Vitamin page that shows what foods provide which vitamins. Below is an overview on why your bird needs these vitamins.
Vitamin A - there are several forms of this vitamin all with different activities in the body. Birds don’t obtain Vitamin A from plants, but obtain its precursors, the Carotenoids. These are generally yellow/orange color of which Carotene is the most important.
Vitamin A is required for:
Integrity of skin
Growth, especially of bones
The liver stores Vitamin A and contains approx. 90% of the body’s Vitamin A. Excess Carotenoids in the diet do not cause toxicity as they are not converted to Vitamin A unless more is required, however, too much may cause the skin and fat to turn yellow. Vitamin A is safe up to ten times normal requirement, however, above this level can cause cataracts and bony deposits. Deficiency in Vitamin A is the most common Vitamin deficiency we see in birds and that comes mostly from feeding seed which is low in this vital vitamin.
Vitamin D - there are two forms of this vitamin in the body; Vitamin D2 from plants and Vitamin D3 which is manufactured by the body
Vitamin D3 is 30 to 40 times more potent than D2 so D2 is generally disregarded. D3 is synthesised in the body by exposure to UV light.
11 to 45 minutes per day of unfiltered light was enough to provide adequate Vitamin D3 to growing chickens. Note that's UNFILTERED light, that means not behind a screen or a pane of glass ... both of which filter out UV light. (See our blog on Avian Lighting.)
Vitamin D3 precursors may be excreted by the preen gland and spread over the feathers. After exposure to UV light and conversion to Vitamin D3, these are re-ingested. This vitamin (D3) also maintains the levels of Calcium in the body. Low Calcium/high Phosphorus diets will precipitate Hypovitaminosis D (Rickets). Birds on low Calcium diets in sunny flights showed no signs of Rickets, yet birds on the same diet in shaded flights showed this disease. Birds in shaded flights may require added Vitamin D3.
Signs of deficiency in Vitamin D3 are similar to those of Calcium deficiency. In hens this includes:
Thin or soft shelled eggs which leads to egg binding
Low clutch size
In young growing birds:
Bent or broken bones
An excess of Vitamin D3 produces calcification of other organs especially the kidneys which can lead to Visceral gout and death. X-rays will show calcification of the kidneys. In clinical studies signs of excess disappeared when Vitamin D levels returned to normal.
Vitamin E - There are 8 forms of Vitamin E found in plants, primarily in the germ of the plant. Vitamin E is most common in oily plants and is an antioxidant that prevents the fats from becoming rancid. Vitamin E is absorbed freely in the bowel but requires proper liver and pancreas function for digestion. It is stored in the liver and in plasma in blood. Plants high in oils provide adequate Vitamin E, but rancid fats (e.g. wheat germ oil left in wheat) will use up this vitamin from the body and create a deficiency. This is another reason whole wheat products aren't recommended.
Vitamin E is one of the least toxic vitamins; however, high doses decrease absorption of vitamins A, D, and K, resulting in reduced hepatic storage of vitamin A, impaired bone mineralization, and
coagulopathy (bleeding disorder where coagulation is impared).
Deficiencies affect the neuromuscular, vascular and reproductive systems. White muscle disease is a type of muscular dystrophy, when this occurs in the gizzard the bird may pass undigested food. Low hatchability (due to weakness in the pipping muscle of the chick) and
splayed legs are the result of Vitamin E deficiencies in parents. Other sypmtoms include brain disfunction or lack of coordination and edema (swelling around the neck, wings or breast).
Vitamin K - is the first of the water soluble Vitamins and is required for blood clotting. It is found in green plants and is also produced by bacteria in the bowel. Deficiencies occur with long term antibiotic treatment which kill off the beneficial bacteria in the bowel.
Deficiencies result in increased bleeding times and toxicities that lead to kidney tubule degeneration. Vitamin K is available as phylloquinone (K1) from plants like cabbage, spinach and other leafy greens; menaquinone (K2) from bacteria in the gut; and menadione (K3) which is synthesized in the intestinal tract.
Vitamin K1 is present as the fat-soluble portion of plant chlorophyll. An energy-dependent process absorbs vitamin K1 from the intestine, whereas vitamins K2 and K3 are passively absorbed. Vitamin K3 has twice the potency of natural vitamin K1 on a weight-to-weight basis.
Thiamine (B1) - This is freely available in most foods and requires constant uptake and is not stored in the body. Deficiencies occur for a number of reasons:
Thiaminasis - there are chemicals in foods which break down Thiamine e.g. fresh fish, caffeine, tannins from tea, wattles and gums or dark coloured vegetables such as beetroot.
Preservatives in foods e.g. Sulphides and Nitrates.
Thiamine deficiency may lead to loss of appetite, opisthotonos, seizures and death. This is uncommon birds that have a balanced diet of vegetables, nuts, and pellets.
Riboflavin (B2) - Occurs in plant and animal tissue especially eggs.
In young chicks, riboflavin deficiency causes weakness and diarrhea, but the bird’s appetite remains normal. Affected birds have toes curled inward both when walking and resting. The skin is rough and dry.
Older birds are more resistant to riboflavin deficiency than juveniles. Breeding hens fed riboflavin-deficient diets may show fatty infiltration of the liver as well as decreased hatchability of their eggs and increased embryo mortality. Heterophil counts may increase and lymphocyte counts decrease. Primary wing feathers may be excessively long. Early treatment with riboflavin will resolve clinical signs; however, in chronic cases permanent nerve damage may occur.
Excesses don’t occur as this vitamin is readily excreted.