Brewers Yeast

Brewer’s Yeast or not?

Article produced by Emily Clarke, Waltham Centre for Pet Nutrition.

Do you ever wonder what all the supplements and little dietary extras actually do for your bird? If you would like to know more about what your feeding regime does for your birds then read on!

Pet birds do not get the opportunity to search for food outside as they would in their native environment. Foraging allows a bird to feed selectively and to supplement its diet in the event of the nutritional balance of the diet being inadequate. The captive bird is therefore dependent on its owner to provide a complete and balanced diet. This places a heavy responsibility on the owner to supply an adequate, balanced diet.

Confusion may occur when nutritional knowledge is transferred between species: what is good for humans is not always good for birds. This article is not intended to be a complete guide to budgie feeding but aims to give budgerigar breeders more background so they are able to make informed decisions about their own aviary nutrition.

It is scientifically accepted that maternal condition is responsible for chick size, vigour, early feeding behaviour and immune response to illness. The nutritional status of the parents is likely to be important over a very long time period, and its influence may extend beyond just the next immediate generation. However, the most dramatic consequences of nutrition appear to occur during the breeding season itself where nutrition can influence sperm quality, nutrient deposition into yolk, egg formation, hatchability, and both short and long term viability of the young.

The 3 major food groups, protein, fat and carbohydrate, are further sub-divided up into classes of nutrients; all of which are essential for health. As well as these nutrients, birds also require energy (fuel). Energy can be gained from any of the nutrient groups but how much energy and how easily it can be used vary greatly. For example, carbohydrates such as starch provide an easily used source of energy and fats provide a more concentrated form of energy that is more difficult to use instantly. Energy supply in budgerigar diets is plentiful, even to excess, so limiting energy whilst maintaining sufficient levels of key nutrients is often a challenge in budgerigar feeding. The list of nutrients required for maintaining health is extensive so this article will focus on some of the most important and easily improved by breeders.


Protein is made of building blocks called amino acids. Birds absorb these amino acids from the gut in a very particular ratio. The ratio of amino acids in a protein source is called its amino acid profile. If the profile of amino acids is wrong in protein, very little of the protein is absorbed. The closer the amino acid profile in the protein is to the amino acid profile required by the bird, the better its quality. An ‘ideal’ protein is one where the amino acid profile perfectly matches the requirements of the bird. In reality, there is no such thing as an ideal protein but egg is usually regarded as the closest to the ideal that we can get.

Sometimes diet components can be mixed together to produce a diet with a good amino acid profile. If the diet is not balanced for amino acid ratio, no amount of supplementation with vitamins or minerals will help. This is where egg food, sprouted seeds and supplemented seed mixes play an important role in breeding. They all contribute different amino acids to the seed-based diet, ensuring the breeding birds are able to absorb plenty of protein in the correct amino acid ratio. If dietary protein is scarce or not available in the correct amino acid ratio, the breeding female will either produce fewer or no eggs or sacrifice her own stores of amino acids (usually in skeletal muscle) to ensure the amino acid profile of the egg is always perfect.

Protein quality in the pre-laying diet also influences breeding success since birds appear able to store essential amino acids in muscle. A study fed two different diets prior to pairing up, one with a poor amino acid profile and one with a good amino acid profile. After pairing, all birds received the same diet but those which had received the better protein diet leading up to lay produced almost twice the weight of eggs and raised three times as many young as those who were fed the poorer diet. Females were also in better condition after laying, losing less muscle mass than the females fed the lower quality diet. Egg supplemented diets have also been shown to improve immunity in young chicks, leading to improved disease resistance.

Protein is not only required for growth and breeding but also for general maintenance of condition. Feathers comprise a large proportion of the total protein in birds, particularly in the sheath. Dietary deficiencies in the amino acids cysteine and methionine may cause feather deformities and deficiency in the amino acid lysine reduces feather strength. The production of feather sheaths during moult increases the protein requirement from the diet. Once again, it is vital that the extra protein provided has an appropriate amino acid profile or the protein will be wasted. When excessive amounts of protein or a poor amino acid profile are fed in the diet, the bird has to break down and excrete this spare protein. The spare protein is also an energy source, which will make birds fat if they do not need this extra energy.

Vitamins and antioxidants

Vitamins are natural components of food found in minute quantities but essential for health. There are six groups of vitamins, which are divided into two basic types. The water-soluble vitamins (B and C) are not stored in the body and so any deficiency in these tends to be quickly apparent, hence daily supplies are essential. The fat-soluble vitamins (A, D, E and K) are well stored in fat and the liver and so daily intake is less critical as long as regular intake occurs.

Each group has its own set of functions and when severely deficient in the diet, display their own set of characteristic deficiency symptoms. The effect on the metabolism is proportional to the level of deficiency so that when deficiency is mild, the symptoms are vague and non-specific. However, breeding is extremely sensitive to vitamin and mineral deficiencies and is often affected long before adult birds show any signs of deficiency. Concentration of vitamins are measured in international units (i.u.) per kg diet or milligrams (mg) per kg diet or mcg (micrograms) per kg) or ppm (parts per million).

Several vitamins are now known to have health benefits beyond alleviating their recognised deficiencies; these are known as antioxidants. The body constantly reacts with oxygen as part of the energy producing processes of cells. As a consequence of this activity, highly reactive molecules are produced known as free radicals. These interact with other molecules within the cell, which can cause oxidative damage to proteins, membranes and genes (oxidative stress). This damage has been implicated in the cause of certain diseases and speeds up the ageing process within cells. Free radicals can be neutralised by a combination of antioxidants produced by the body and those supplied in the diet neutralise free radicals.

Reproduction causes oxidative stress to the parent birds so diets containing antioxidants are beneficial. Hatching also causes oxidative stress, and it is well accepted that addition of antioxidant sources to maternal diet improves the antioxidant status of chicks.

Role of Vitamins

Vitamin A is necessary for healthy skin and mucus membranes, including the lining of the mouth, sinuses and cloaca. The low levels of vitamin A in seed diets have made vitamin A supplementation a standard diet feature. However, a two-year experiment feeding female cockatiels varying levels of vitamin A concluded that they are much more susceptible to vitamin A toxicity than deficiency. This is not to say vitamin A supplementation is unnecessary but serves to highlight the importance of correct dosage. Vitamin A can also be given to birds in a different form as beta-carotene. The bird is able to transform beta-carotene into vitamin A as required but, unlike vitamin A, beta-carotene is not stored in excessive amounts by the bird so there is no risk of toxicity.

The B vitamins are a large group of compounds that work together to promote growth, reproductive health, nervous system function, resistance to disease, feather and skin health, and many other functions. They are among the most important group of vitamins for birds, due to egg production and the rapid growth requirements of chicks.

The B vitamins currently known (there may be more) include B1 (thiamine), B2 (riboflavin), B3 (Niacin), B6 (pyridoxine), B9 (Folic acid), B12 (cyanocobalamin), Biotin, Pantothenic acid, choline, inositol, and PABA (para-amino benzoic acid). The total spectrum of the B vitamins has not yet been completely identified, and all of their functions are not known.

It is known that the B vitamins work together, which is called working synergistically. Like the fat-soluble vitamins, the B vitamins also compete for uptake so too much of one or more B vitamins can bring about a deficiency in other B vitamins. Thus the complete spectrum of B vitamins needs to be consumed. The B Vitamins assist the body in responding to stress, so this vitamin is even more important during breeding, moulting, and quarantine periods. These vitamins also aid in the digestion of carbohydrates and proteins.

Vitamin C is a metabolic regulator. In most species of seed-eating birds vitamin C is synthesised in the liver in sufficient quantities to avoid deficiency symptoms but the antioxidant properties of vitamin C mean it still provides benefits as a supplement in the diet.

Vitamin D is necessary for the absorption of calcium and phosphorus from the gut into the body. Vitamin D comes in many slightly different forms. The formed required by birds is 1,25-dihydroxycholecalciferol: Vitamin D3. Birds can make their own vitamin D3 if they have access to UV light (from a UV lamp or daylight).

It is obligatory for adequate vitamin D3 to be available for the proper absorption of calcium and phosphorus to take place. Inadequate vitamin D3 levels in the body can lead to calcium deficiency symptoms in an otherwise calcium-adequate diet.

Vitamin E is the fertility vitamin. High levels of Vitamin E (a potent anti-oxidant) have been shown to improve chick quality and boost immunity. Vitamin E is one of the least toxic vitamins, however, very high doses decrease absorption of vitamins A, D and K, resulting in reduced liver and egg yolk storage of vitamin A and impaired bone mineralization. Vitamin E also influences male fertility: avian sperm benefit from increased antioxidant levels in the diet.

Vitamin K is necessary for blood coagulation. It is found in green plants and can be produced by the normal bacteria in the birds’ bowel. It is in fact quite difficult to produce a vitamin K deficiency unless antibiotics have been overused and have killed all of the bacteria in the bowel or birds are prevented from eating their own droppings or probiotics are not used.

Table 1: Good sources of each vitamin and 3 key amino acids:

Vitamin A Yellow squash, sweet potatoes, carrots, egg yolks, kale, cod liver oil, broccoli, chicory, chard, green peppers, dandelion, carrots
Vitamin B Eggs, cheese, nuts, sunflower seeds, millet seeds, green leafy vegetables, broccoli, bananas, wheat germ, brewer’s yeast, liver, Marmite, (some sources all contain some but not all of the B vitamins
Vitamin C Broccoli, red peppers, green peppers, tomatoes, peas, kiwi fruit, oranges, strawberries, melon
Vitamin D3 Egg yolk, sunlight, cod liver oil, oily fish, sweet potatoes, dark green leafy vegetables
Vitamin E Egg yolk and white, green leafy vegetables, watercress, oats, wheat germ, almonds, cashew, corn, sun flower seeds, liver, pumpkin seeds
Vitamin K Kelp, alfalfa, green leafy vegetables, eggs, soya beans, Lysine Legumes (e.g. peas, soya), high lysine corn, poultry, fish, eggs, dairy products, nuts, meat and brewer’s yeast. Methionine + Cysteine Spinach, green peas, nuts, meat, sesame seed, egg


Keeping vitamins balanced

It can be seen from the descriptions above that all the vitamins have essential roles in maintaining health. Even in diets carefully supplemented with every vitamin on the list, it is possible for your bird to have vitamin deficiencies: the fat-soluble vitamins often share a special carrier protein that transports them from the gut into the body tissues. They have to compete for these absorption sites in the gut and any of them can be squeezed out through over-supplementation of another vitamin.

Dietary excess of one vitamin can diminish uptake and lead to deficiency of another, despite adequate levels in the diet. Vitamins not only interact with each other but also with other substances such as amino acids and minerals. The most significant relationships between vitamins and minerals are the relationship between calcium, phosphorus and vitamin D3 and the relationship between vitamin E and selenium. Vitamin E and selenium perform the same role: if one is deficient, then the other can make up the difference. The B vitamin niacin and the amino acid tryptophan are also able to substitute for each other. Current recommendation levels and dietary sources of vitamins are shown in the table below (table 2).

Table 2: Recommended level of vitamins in budgie diets:

Vitamin A activity (total) IU/kg 2000 10000
Vitamin D3, ICU/kg 500 2000
Vitamin E, ppm 50 unknown
Vitamin K, ppm 1 unknown
Biotin, ppm 25 unknown
Choline, ppm 1500 unknown
Folic acid, ppm 1.5 unknown
Niacin, ppm 50 unknown
Pantothenic acid, ppm 20 unknown
Pyridoxine, ppm 6 unknown
Riboflavin, ppm 6 unknown
Thiamine, ppm 4 unknown
Vitamin B12, ppm 0.1 unknown

Vitamin toxicity

The water-soluble vitamins are not stored in the body so a daily supply is required. This also means that overdosing with water-soluble vitamins is less likely although B vitamin overdose is possible and excessive vitamin C may cause irritation to the gut and diarrhoea.

The fat -soluble vitamins are stored in the body and overdose of these vitamins is much more serious. Table 2 shows the current recommended levels of vitamins and maximum recommended levels of vitamins A and D. Excessive supplementation of the other vitamins is also detrimental for the reasons discussed earlier but exact maximum figures have not yet been determined.


The mineral status of the laying female determines the amount of each mineral transferred to the egg and the mineral stores of the hatchling. There is a complex set of interrelationships that exist between the different minerals in the bird. This is largely as a result of the fact that in order for minerals to be absorbed by a bird, they first need to be transported across the gut wall, mostly by what is known as a carrier protein. The different minerals are believed to compete for these proteins, which is why an excessive level of a mineral can and does inhibit the absorption of another. Certain minerals also have key roles in reproduction. This will be covered in more detail in a future article.

In conclusion, this article is an overview to help breeders in deciding whether a new diet ingredient might be of benefit to their aviary or whether they have already accounted for those nutrients in their feeding regime. Remember: more isn’t always better! Unless dietary protein is well balanced, all the vitamin/mineral supplements in the world are not going to help breeding and in excess they may harm your birds. All the nutrition facts stated in this article are taken from scientific reports.

If you would like more detail about the information sources used a reference list is available.

Liver disease

Liver disease is a slow, on-going progressive disease where the liver tissue is replaced with fat. When the liver disease has progressed, the bird may suddenly appear ill.

Females appear to be more affected than males; this may be linked to the hormonal activities in the reproductive hen. Also juvenile birds may be diagnosed with this disease. This usually happens in hand-feeding birds that are either continuously overfed or hand-fed long after they should have been weaned. Hand feeding formulas are calorie-dense and baby birds tend to be sedentary. Any extra calories tend to end up being stored as fat in the liver. This most often is seen in cockatoos as they tend to beg even after satiated.


  • The enlarged liver may cause breathing difficulties as the organ compromises the body cavity space.
  • The bird’s abdomen may appear distended, and sometimes the liver is actually visible below the keel.
  • The bird may develop diarrhoea, and the droppings may take on a more yellowish or greenish hue due to biliverdin being excreted.
  • Poor feather quality and changes in the feather coloration. In cockatiels, for example, the white feathers may take on a more yellowish colour (doesn’t happen in white-faced cockatiels though). African Greys may develop red feathers in areas that are usually grey and feathers in Eclectuses may turn yellow, orange and potentially red.
  • Dry itchy skin may also be an indicator of liver problem. Once the liver problems have been resolved, it takes a while for the itching to stop.
  • In some birds, soft areas around the beak occur. Birds may develop overgrown beaks and claws / nails.
  • End-stage liver disease: toxins build up in the bloodstream, resulting in central nervous systems signs, such as disorientation or seizures
  • Bleeding clotting problems may occur. A simple broken blood feather may result in prolonged, life-threatening bleeding

Supporting a Healthy Liver through Nutrition and Healthy Lifestyle:

  • Restorative sleep is crucial as it helps promote healing, including helping a liver rebuild itself. Patients (feathered or unfeathered) need extra sleep and plenty of rest to recover.
  • Diet: Your avian vet is likely to recommend changes to your pet’s diet.
    • It is important to change to an ORGANIC diet that is rich in fiber, low in fat and with reduced protein content . The liver should not be burdened with the pesticides that are typically found on conventionally grown produce.
    • The staple diet should consist mainly of fruits and vegetables with a good quality dry food mix (that doesn’t contain any chemicals, artificial flavours or colours). Foods to focus on are those that will help the liver detoxify.
    • Foods and nutrients that aid in the detoxification process include: Magnesium, Vitamin C, foods rich in Vitamin B2, B5, B6, B12, walnuts, cabbage, broccoli, Brussels sprouts, asparagus, citrus peel, egg yolks, garlic, red peppers, dark green leafy vegetables, animal protein, whole unprocessed grains, some legumes, and turmeric.

Fibre is important for cleansing the intestines of toxins. Encouraging the consumption of fresh fruits and unlimited amounts of fresh vegetables adds fibre and nutrients.

    • Sprouted seeds are an excellent option. Sprouted seeds are lower in fat, as the process of sprouting utilizes the fat stored in the seed to start the growing process – thus reducing the fat stored in the seeds. Also, the texture is more vegetable-like, which may encourage a bird to begin eating veggies. Sprouted or germinated seeds are usually more easily accepted by “seed addicts” than fresh fruits and vegetables.
    • Do not feed peanuts or food items that could contain mycotoxins, which could further damage the liver.

  Nutritional supplements that support liver function are:

  • It is suspected that there is a correlation between vitamin deficiency and the development of fatty liver disease; and nutritional support is essential for the treatment. The following supplements should be discussed with a holistic vet:
    • Choline, biotin and methionine. Biotin and choline (B vitamins). Choline is essential for fat metabolism. It helps prevent the deposition of fats in the liver, guarding against fatty liver damage. Animals with choline deficiencies have been shown to develop liver damage similar to that induced by alcohol in humans.
      • Foods that are high in choline are egg yolks, brewer’s yeast, legumes and whole grain cereals.
      • Sources of biotin are nuts, fruits, brewer’s yeast, and brown rice.
    • Methionine (an amino acid that is essential in transporting fats from cells) – can be found in: eggs, fish, meat and milk. However, do not offer any anything containing lactose, as birds cannot digest this sugar. However, lactose is almost entirely removed in the process of manufacturing of many cheese products, yogurt or cottage cheese, making those items generally safe for consumption by birds. Discuss the diet with your vet.
    • Milk thistle is very good support for a damaged liver. Your avian vet will decide if this is an appropriate therapeutic for your bird. Make sure that any milk thistle supplement does not contain ethyl alcohol as a base, as that can potentially intoxicate a small bird and alcohol can also further damage the liver.
    • Dimethylglycine (DMG) – an antioxidant – is also a good supplement for birds with liver damage.
  • The following supplements will help with detoxifying your birds:
    • Aloe Detox – One recommended brand is “Lily of the Desert Aloe Detoxifying Formula.” It is available over the following websites:;; It is also available at better health food stores, such as Whole Foods. The manufacturer reports that Aloe Detox needs to be refrigerated (obviously). After opening, it will keep for 7 to 9 months.
      • Birds with advanced liver disease that have been given only weeks to live by the vet turned completely around after daily administration of Aloe Detox by the owner. A holistic vet recommended “as much of Aloe Detox” as the owner could get the parrot to drink. In that case, it was 1/2 oz three times a day (it was a larger parrot) – dilution: one part Aloe Detox to three parts water. (Owner used filtered / distilled water). After three weeks, the parrot’s blood work was completely normal and the parrot lived many years afterwards. If a pet doesn’t want to drink it, soaking a pet’s favorite “birdie bread”, whole grain toast, or favorite treat might be a good way to administer it. A vet recommended not to give Aloe Detox for extended periods – only when detoxifcation is needed; no longer than 3 weeks. If administered in drinking water, some birds who might not like the taste, may stop drinking! Make sure your pet stays sufficiently hydrated. Discuss a treatment program that is right for your pet with your holistic vet.

One bird owner described her experience with her dying canary. The prescribed medications caused the canary to get worse, rather than better. She researched Aloe Detox and decided to stop any prescribed medication and take the holistic route. She administered Aloe Detox and the canary gradually improved and completely recovered.

  • The directions provided were (please discuss with your holistic vet):
  • For seriously sick birds: mix 50/50 or 60/40 detox / spring water and provide as drinking. Please make sure your pet drinks it or else administer with a feeding syringe. Hydration is vital — so owner need to make sure that the pet takes in sufficient amounts of fluids. Place the water dish very close to where the bird is sitting. Keep the cage in a warm environment. If a bird is dehydrated and unable to drink on its own, use a small dropper or feeding syringe and place a few drops directly into the bird’s beak. Once normal hydration levels have been reached, you should see an improvement in your pet within 15 to 20 minutes. As soon as the bird is drinking on its own, stop administering directly.
  • Detoxification in Well Birds: Breeders may provide Aloe Detox to their flock once a week to help with detoxification and maintain their health. Adding a tablespoon or so to two ounces of water will help maintain the health of the flock. Some breeders provide a 50/50 mixture (Aloe Detox / Water) once a week — besides helping with detoxification it also gets them used to drinking it so in case they have problems in the future, they will easily accept . However, if your birds appear to reject the detox, reduce the amount and gradually increase the ratio over a few days. Please note that Aloe Detox does spoil — so it is best to replace it with fresh water after a few hours – particularly on hot days. The manufacturer reports that Aloe Detox needs to be refrigerated (obviously). After opening, it will keep for 7 to 9 months.
  • Some bird owners mix Aloe Detox in with juice to get their birds to drink it.
  • Fresh gel from the leaves are superior to Aloe Vera gel bought commercially. Bird owners will cut off a small section each day and feed that section to their pet birds. The plant is easy to grow in most areas. It needs, however, to be grown organically — without the use of chemical fertilizers, pesticides or herbicides.
  • *NOTE: Even though Aloe Vera is helpful for many birds, some rare birds may have a reaction to Aloe Vera. Spray one of your fngers and touch your bird’s foot. Leave for 24 hours and see if an reaction occurs
    • Herbs that are conducive to maintaining liver health and even reversing existing liver problems are: Psillium Husk Powder, Dandelions and others.
    • Milk thistle is a liver-supportive herb. It’s best to discuss with your vet whether it is appropriate for your pet. It is important to make sure that any milk thistle supplement doesn’t contain ethyl alcohol as a base, as alcohol can further damage the liver.
    • Alpha-Lipoic Acid has been used successfully for the maintenance of liver health and as a treatment for several toxin-related illnesses. ALA has been used extensively in Europe for years as a non-toxic nutrient to treat toxic conditions such as mushroom poisoning, diabetic neuropathy, and elevated liver enzymes. Another benefit of Alpha-Lipoic acid may be its ability to elevate the levels of glutathione (GSH).
    • Conjugated linoleic acid (CLA) reduces the body’s ability to store fat, while promoting the use of stored fat for energy. Cattle and chickens that are fed grain, rather than allowed to feed in pastures, are low in CLA, which has caused a dramatic reduction in the amount of available CLA in the American diet in recent years.
      • Sources: Eggs, meat and dairy products. Note: Meat from grass-fed animals contain much higher levels of CLA than meat coming from grain-fed animals.

In many cases there are secondary infections along with the liver disease, and the vet will (or should) ensure that any medications are not toxic to the liver. Many medications are removed or changed by the liver, so the vet may adjust dosages accordingly.

Exercise: When dealing with a sedentary bird, exercises will need to begin slowly and progress gradually in intensity. Wing-flapping exercises, ladder-climbing and walking are safe; however, the bird should be monitored closely to ensure that he or she is not becoming over-exerted at any time.

 Nutritional Supplements

Budgerigars may eat corn as a treat now and then, but be sure to include treats that supplement your bird’s nutrition. Cod liver oil helps indoor budgies manufacture vitamin D, while a pinch of brewer’s yeast every other day will help them get their B vitamins. Add eight drops of cod liver oil to each pound of birdseed. You can also feed budgies a bit of boiled egg yolk combined with cracker crumbs for protein, or a small amount of bread soaked in milk.



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