Vitamin Deficiencies in Birds: Vitamin A Deficiency

 

Vitamin deficiencies in birds are often caused by a lack of essential vitamins in their diet. While multiple signs can appear, B vitamin deficiencies tend to show up first.

Fat-soluble vitamins, like vitamin A, can be stored in the body, so deficiencies may take longer to manifest, especially in adult birds.

Prevention and Treatment

Ensure your bird's diet includes a balanced vitamin premix to prevent and treat vitamin deficiencies. This is often added to their food in a microencapsulated form.

Factors Affecting Vitamin Efficacy

The effectiveness of vitamins in bird feed can be influenced by factors like:

• Time: Over time, vitamins can degrade.
• Temperature: High temperatures can accelerate vitamin loss.
• Humidity: Moist environments can also contribute to vitamin degradation.

Storing Bird Feed

To maintain the vitamin content of your bird's feed, store it in a cool, dry place. Most commercial bird feeds retain their vitamin potency for about 2 months when stored properly.

Vitamin A Deficiency

Vitamin A supports critical functions like vision, immune defence, and skin health in birds. It also helps in maintaining the mucous membranes lining the respiratory, digestive, and reproductive systems, keeping infections at bay.

If birds are fed a vitamin A-deficient diet, signs of deficiency don't develop for 2-5 months, but this duration depends on the amount of vitamin A in the liver stores of that bird. Birds eventually have ruffled feathers and become weak and malnourished. Hatchability declines, embryonic mortality rises, and egg output sharply declines. The ovary will probably only contain tiny follicles when egg production decreases, some of which may exhibit bleeding symptoms. Additionally, a watery discharge from the eyes may be observed. Birds with xerophthalmia, a condition in which a milky white, cheesy substance builds up in the eyes, are unable to see. The eye may be destroyed in numerous cases.

The upper alimentary tract's mucous glands are typically the first lesions seen in adult birds. A stratified squamous keratinised layer replaces the normal epithelium. This causes necrotic discharges by obstructing the mucous glands' ducts. The mouth, oesophagus, throat, and nasal passages can all have tiny, white pustules that can spread into the crop. Pathogenic germs can typically infiltrate these tissues and result in subsequent infections when the mucous membrane breaks down.

Day-old chicks raised on a diet low in vitamin A may exhibit symptoms within 7 days, depending on the amount of vitamin A inherited from the breeder hen. However, it might take up to seven weeks for chicks with a healthy maternal vitamin A reserve to exhibit symptoms of a deficit. Anorexia, growth retardation, frailty, lethargy, emaciation, ruffled feathers, and incoordination are all considered gross indications in chicks. As with vitamin E deficiency, the chicks may become ataxic if the shortage is severe. Typically, the comb and wattles are pale, and the yellow colour in the shanks and beaks has been removed. Although xerophthalmia is rarely observed since chicks typically pass away before the eyes are impacted, a cheesy substance may be observed in the eyes. Secondary infection may play a role in many of the deaths noted in the birds having acute vitamin A deficiency.

Chronic vitamin A deficiency in young chicks can also result in the development of oesophagal mucous membrane pustules, which typically impact the respiratory tract. Uric acid deposits can cause the kidneys to become pale and the tubules swell; urates can clog the ureters in severe situations. Uric acid levels in the blood can increase from about 5 mg to 40 mg/100 mL. While a lack of vitamin A does not affect the metabolism of uric acid, it does stop the kidneys from excreting uric acid normally.

In contrast to vitamin E-deficient chicks, who have degeneration of Purkinje cells in the cerebellum, vitamin A-deficient chicks do not have any gross lesions in their brains, although they may be ataxic, like those with vitamin E deficiency. Chicks with ataxic vitamin A deficiency have little to no vitamin A in their livers.

There is little chance of a deficit because chicken diets almost always contain stabilised vitamin A supplementation. However, up to twice the typically advised amount should be fed for about two weeks if a deficiency does occur due to either an unintentional failure to take the vitamin A supplement or poor feed preparation. When vitamin A is given through drinking water, recovery is typically quicker than when it is supplemented through feed.

FAQs

1. What foods are high in vitamin A for birds?
   Foods like carrots, sweet potatoes, and leafy greens are rich in vitamin A and should be included in their diet.

2. Can vitamin A deficiency be reversed?
   Yes, with early intervention and proper care, birds can recover from vitamin A deficiency.

3. How do I know if my bird has a vitamin deficiency?
   Look for signs like dull feathers, lethargy, and respiratory issues, and consult a vet for a diagnosis.

4. Are supplements safe for birds?
   When recommended by a veterinarian, supplements can safely fill nutritional gaps.

5. Why is a seed-only diet harmful?
   Seeds lack essential nutrients, including vitamin A, leading to deficiencies over time.