What To Feed (2nd Part) (2003)

B eginning in the late 1970s studies were undertaken at the University of California Davis Campus to determine the nutritional requirements of Cockatiels. As a result of these studies manufactured diets began to appear that meet the nutritional needs of most seed eating species. Manufactured Diets Along with the appearance·of the manufactured diets, came advertising campaigns designed to convince people that the new diets were superior to seed based diets. Avian veterinarians soon joined in on the side of the manufactured diets. Since many if not most of the diseases and premature deaths they were seeing in their avian patients were diet related, the veterinarians became the most vocal and persistent spokesmen for manufactured diets. In their eagerness to convince bird owners of the advantage of manufactured diets, manufacturers and veterinarians alike often resorted to hyperbole and exaggeration. Statements comparing seed based diets to junk food, assertions that feeding seeds was a death sentence for a bird, claims that all seeds were devoid of nutritional value, that all seeds were high in fat and low in nutrients were made and largely went unchallenged. Seed Based Diets So, how do seed diets stack up against manufactured diets? Are seeds really as bad as the makers of manufactured diets would have us believe. The answer to that question is quite complex. Any examination of the value of seed based diets needs to recognize that the available diets will vary greatly in content, and quality, both of which strongly influence the nutritional value of the mix. It is also necessary to acknowledge that supplements are necessary (especially for Vitamin D3) for those nutrients that are typically low or missing from most seeds. Still it is possible to construct a diet based on seeds that is comparable to manufactured diets. Variety of Seeds Seed varies greatly in nutritional content. It is therefore necessary to design seed-based diets using several different seeds. Some seeds, particularly the oil seeds such as safflower, sunflower, rape, and sesame are high in minerals and vitamins but also high in fat. Others such as millet are quite low in fat, are low in minerals, but many have good amounts of protein. What most seeds lack is vitamin A and calcium. Vitamin A The highest vitamin A content is found in the oil seed. Sunflower contains 500 IU (injectable units) per kilogram, while safflower contains the same amount, but they are the exception. Most seed such as millets and other grains contain little or no vitamin A. Calcium Calcium is also a problem in seed diets. Again, the oil seed tend to be the best sources. Sunflower contains 1160 mg/Kg while Sesame contains 9750 mg/Kg. Non oil seed such as millet, oats, and buckwheat tend to be much lower. Canary seed while a good source of calcium is quite high in phosphorus  which can skew the calcium phosphorus ratio dramatically. Vitamin D No seed or other vegetable product contains vitamin D in any form. This can present serious problems for birds kept indoors as in order to manufacture vitamin D3 they must be exposed to ultraviolet light at a high enough intensity to activate chemicals contained in their preen gland and in, their skin. Birds kept inside generally do not receive sufficient exposure to ultraviolet to produce adequate amounts of vitamin D on their own. Birds kept outside and exposed to unfiltered sunlight do not experience this problem. Vitamin D deficiency contributes to many health problems ranging from decreased auto-immune response to liver and kidney failure. Vitamin D deficiency is of special concern to breeders as it is required to bind calcium and a deficiency can cause egg binding, soft-shelled eggs, and cause development problems in chicks. It is important that this lack be corrected in any seed diet fed to birds kept inside. Vitamin supplements can be added to the food, or foods such as egg, hard cheeses, meats, or fish can be added to the diet to provide sufficient vitamin D. Great care should be taken when supplementing vitamin D through the use of vitamin powders or solutions. While I am not aware of any clear studies demonstrating at what level vitamin D becomes toxic in birds, anecdotal evidence seems to indicate that levels above 2,000 IU/Kg may be toxic for some species.