Avian Nutrition: It’s for the Birds

Every pet that comes into the veterinary hospital is affected by nutrition—including companion birds. There are 3 components that affect the life of an animal: genetics, environment, and nutrition. Health is directly linked to quality of life and life span of the avian species. Nutrition is the one factor that the veterinary healthcare team can impact. Proper nutrition and feeding management are the cornerstones upon which healing and the maintenance of health rest.

This article was originally published in the 2021 VMX Conference Proceedings.

Each species of bird has specific nutritional requirements determined by its individual physiology.^1,2 As in other species, nutrition must be viewed in lifestages as nutritional requirements in birds vary from neonate to adult to senior—with other lifestage variations in between. A balanced diet should be provided for optimal health. To achieve a complete and balanced diet, it is recommended to feed a commercially formulated food. These formulated foods come in a variety of forms, with the most popular being pellets, extruded diets with a pellet appearance, whole grains, and seeds with added pelleted material.^2,3 

One other option would be a seed-based food with a vitamin/mineral mix coated on the outside of the seed. However, the seed is often not hulled. Therefore, when the bird dehulls seeds, essential vitamins and minerals are removed, thus creating a nutritional imbalance and putting the bird’s health at risk.

Two processes are used when pelleted diets are manufactured, bound, and extruded.^4,5 In manufacturing, grains such as corn, soybean, and oat groats are ground. Following the grinding process, vitamins, minerals, and other components are added to make a balanced food. The grinding process produces a consistent pellet, which makes it difficult for birds to pick out their favorite part of the diet. With bound pellets in general, the food material is not cooked, and the diet will have a longer fiber chain length. Bound pelleted diets may not be as palatable as the extruded diet.^3,5,6 

Extruded pellets utilize finely ground grains that are mixed with vitamins, minerals, etc. until a balanced formulation is reached. This pellet mixture is then forced through an extruder, under pressure and high temperatures. The mixture will take on the shape of the “die” in the extrusion process, similar to the way a cookie cutter works. This allows for extruded pellets to be made into different shapes and colors.^2,5

Extruded pelleted diets come in a variety of sizes and should be selected based on the species and size of bird. Owners must be instructed to monitor their bird to prevent the bird from picking out certain colored pellets and ignoring others. Owners should not choose colors or shapes based on how they perceive the bird’s preference. Companion birds are healthier when they are psychologically stimulated, and this can occur by presenting multicolored pellets in an assortment of shapes.

Historically, providing diets for birds has included seed-based diets. Although pelleted diets have allowed bird owners to provide a better-balanced diet without vitamin and mineral supplementation, not every bird will eat them.^4,5,7 Also, as discussed earlier, each species has different nutritional requirements. For example, certain canary and finch species require seed in their base diet. However, for the psittacine species, seed is not the recommended diet and a balanced pelleted food is advised as the appropriate base diet. Overall, many seed diets are high in fat and lower in other essential nutrients and therefore should be considered a treat. As with any species, treats should be offered in small quantities or the bird will be at risk for malnutrition—most likely obesity. 

Transition from a seed diet to a pellet is believed to be difficult. However, this is not the case even in older birds. Healthcare team members must educate owners on what to look for when transitioning a bird from seed to pellets. Owners should ensure that their pet is ingesting the food, not simply crushing the pellet in the hopes of finding a kernel inside. Two signs that indicate that the bird is actually eating the pellets are seen in the production of fecal material and a color change of the feces associated with the pellet color being ingested.^2,5

To aid owners in transitioning their birds from seed to pellet, formed seed products have been manufactured (e.g., Nutri-Berries [Lafeber Company, lafeber.com]). These products are composed of whole grains and seeds that are mixed with additional components and are stuck together. This is similar to pellets but this product is not ground. The bird must pick off the seed to eat (FIGURE 1).

Figure 1. Meyer’s parrot with Nutri-Berries food.

Owners can also learn to transition their birds from seed to pellets through the slow introduction of increased pellets in the seed mixture over a period of time. The transition is recommended to take 7 to 14 days, with the final diet consisting of 100% pellets. If a longer transition is needed, educate owners that it is OK—the important point being that the bird does ultimately transition to pellets.

Key Nutritional Factors

Water

Water is the most critical nutrient, and all birds should have access to fresh, clean water at all times. Water should be changed on a daily basis, and the healthcare team is responsible for reviewing this important piece of husbandry with owners. Birds typically accept municipal tap water, but it is recommended that well water be boiled before allowing the bird to drink freely. This recommendation is made due to the fact that well water can be contaminated easily by bacteria colonies in the pipes leading to the faucet.^3,7

Protein and Amino Acids

Protein requirements differ among species. The minimum recommended protein allowance for maintenance in granivorous companion birds is 12%.^2,8

As with all foods, the quality of the protein is dependent upon bioavailability and essential amino acid content. Avian formulations must avoid an excess and deficiency of proteins and amino acids. For the majority of companion birds the following amino acids are considered essential: arginine, isoleucine, lysine, methionine, phenylalanine, valine, tryptophan, and threonine. Budgies also require glycine.^2,8 

Too much protein in the diet of birds has been associated with renal disease, behavioral changes (biting, feather picking, nervousness, rejection of food), and regurgitation. Poor weight gain, poor feathering, stress lines on feathers, plumage color changes, and poor reproductive performance are clinical signs associated with protein and amino acid deficiencies.^2,8 

Fats and Essential Fatty Acids

Fats are a more concentrated source of energy in a diet. Essential fatty acids (linoleic and arachidonic) are required in birds for the formation of membranes and cell organelles, hormone precursors, and the basis for psittacofulvins (i.e., feather pigments found in psittacine species). Typically, the recommended fat allowance for granivorous companion bird diets is approximately 4%.⁸ Healthcare team members should note that in birds lipogenesis takes place primarily in the liver. Pet birds fed high energy diets may develop illness associated with hepatic lipidosis. This is heightened if exercise is restricted in the bird.

As with other companion animals, too much fat in the bird’s diet may result in obesity, congestive heart failure, diarrhea, as well as oily feather texture. Elevated fat levels may also interfere with the absorption of other nutrients such as calcium. Low amounts of fat in the diet may lead to weight loss, reduced disease resistance, and overall poor growth, especially when coupled with restriction of other energy-producing nutrients.^7,9 

Carbohydrates

Carbohydrates are another energy source that in birds can be converted into fat in the liver and vice versa. Glucagon is the major component of carbohydrate metabolism in birds. The result of inadequate carbohydrates in the diet is the utilization of glucogenic amino acids to manufacture carbohydrates. The process involves amino acids being shifted away from growth and production and instead utilized in glucose synthesis.

Carbohydrates are the only source of energy utilizable by the nervous system; therefore, neurologic abnormalities may indicate deficiency in a diet that is otherwise adequate in kilojoule content.⁹

Calcium

Calcium is an important dietary element for companion and caged birds. Calcium is essential for bone and eggshell formation. Calcium is also necessary for blood coagulation and nerve and muscle function. It is recommended that all birds should have calcium supplementation regardless of the type of diet they are eating. This is especially true for birds fed a seed diet. Calcium supplementation can be provided in the form of a cuttlebone, mineral block, crushed oyster shell, or baked crushed eggshell. Birds will eat the calcium if provided and when needed to meet physiologic demands. Cuttlebones should be placed in the cage with the soft side facing the bird. Cuttlebones are strictly a calcium source and are not beak sharpening devices.^2,5 It should be noted that high phosphorous in the diet can negate adequate amounts of calcium. High phosphate levels will interfere with calcium absorption from the intestinal tract. The calcium:phosphorus ratio should range from 1:1 to 2:1.^5,9

Vitamins and Minerals

Vitamin requirements for companion birds are similar to those of companion mammals. The major exception is that the active form of vitamin D required by birds is vitamin D3 (cholecalciferol) as opposed to vitamin D2 (ergocalciferol). Vitamin C is only important in specific fruit-eating species. However, vitamin C has been suggested to assist debilitated birds as their ability to create vitamin C is reduced and the patients’ requirements are greater.^7,9

If the bird is prescribed antibiotics, the healthcare team should monitor the patient closely as vitamin deficiencies may result from the antibiotics interfering with normal intestinal microflora. Intestinal infections (e.g., giardiasis) may block vitamin absorption from the intestine (e.g., vitamin E, vitamin A). Hypervitaminosis has become an increasing problem, as clients may over-supplement formulated food or multivitamin preparations, thereby causing renal failure due to hypervitaminosis D. Hypervitaminosis A can also result in disease problems, especially in nectivorous birds.

Fruits and Vegetables

Fruits and vegetables are typically presented as supplementation to the pet birds’ commercial diet. Fruits are made up of mainly sugars and water and thus should not be offered in excess. Fruit is a necessary part of the diet for some psittacine species such as eclectus and lories, but these are exceptions. Fruit should not be fed more than a couple of times in a 7-day period. 

Companion birds receive greater nutritional benefit from vegetables versus fruits. As much as possible, fresh or cooked dark green, red, and orange vegetables should be offered on a daily basis. One vegetable that should not be offered is comfrey. Comfrey is a green leafy herb especially popular in canary aviaries, which may result in liver damage. Proper husbandry is of the utmost importance. The healthcare team should educate owners to place fruit and vegetables in a separate container and leave in the cage no longer than 30 minutes.^3-5 Time restriction will help decrease the likelihood of microorganism growth. 

Summary

Feeding practices of companion birds are constantly being evaluated in the pursuit of providing optimal nutrition for all avian species. It is imperative that veterinary team members understand the key nutritional factors in avian nutrition. This will allow for the proper recommendation and education of nutrition to bird owners. Pet bird owners influence their bird’s diet and therefore have a major impact on their birds’ health and longevity. Educating the owner on proper nutrition is one of the most important roles of the veterinary healthcare team. 

Disclosure

Kara Burns is a nutritional consultant for the Lafeber Company.