Avian nutrition has a history going back to the 1800s when some of the first vitamin investigations relied heavily upon the use of chicks. Today the commercial chicken is perhaps one of the most studied and best understood nutritional models. Nutrition of exotic and pet birds, however, has only recently been studied in a systematic and scientific manner. There have been many obstacles to being able to provide a complete and balanced diet to these birds including the lack of knowledge of their diets in the wild, lack of funds for research and a lack of interest by researchers. Now, though, things are definitely improving.
As most people have come to realize, proper nutrition is essential to good health. Nutrition effects all aspects of the body including growth, reproduction and immune function. Many of the most common problems seen in exotic pets are noninfectious diseases which may stem from nutritional imbalances. Often times the needs of a particular species are simply unknown and there is little information on their diet in the wild. There is a small amount of information available but it is simply very difficult to obtain information on the dietary habits of free ranging birds (Ul!rey et al 1991). Frequently, the owner provides an inadequate or unbalanced diet. The belief that an all seed diet is proper for pet birds is still widely held by owners. Other times the bird may be offered an adequate diet but through individual preference pick out only a certain type of food stuff and create an imbalance.
The commercial chicken is physiologically and anatomically very similar to exotic birds. At first, it was thought that parrot information could be extrapolated directly from the chicken data. Unfortunately, though, studies have proven that the nutritional needs
of a chicken do not necessarily translate to the needs of a psittacine . . Various amino acid and vitamin deficiencies studied have found different expressions in Cockatiels as opposed to chickens (Grau and Roudybush, 1985, Roudybush and Grau, 1991).
It must be remembered that the chicken is a precocial species while psittacines are altricial. Thus, studies involving the species of interest must be conducted to truly define the nutritional needs of that bird. A few have been done for the Budgerigar (Earle and Clarke, 1991) and the Cockatiel (Roudybush and Grau, 1991).
There are six basic nutrient groups which serve as the foundation for nutrition. These include water, protein, carbohydrates, fats, vitamins, and minerals. Nutrients are food constituents which serve to support life processes. They perform functions such as being structural components, metabolism, transport of other substances, and supply energy.
Water is the most important nutrient. Animals can live much longer without food than without water. A 10% Joss in total body water can cause severe illness. Poor water quality can be a source of many health problems. Too frequently, people feel it is adequate to simply top off the water containers for their birds and neglect proper hygiene. Bacteria reproduce quickly in wet and warm conditions. The use of water soluble vitamin supplements, the presence of foodstuff or fecal matter and lack of clean water dishes can lead to substantially high bacterial counts in your birds' drinking water. Many aviaries have adopted automatic nipple drinkers to avoid these prob-
Ierns. Also, bottled water is not necessarily sterile water. Keep this in mind when mixing formula for handfeeding. If your nursery is having a problem with handfeeding youngsters, be sure to evaluate your water source.
Protein and specifically amino acids provide the building blocks for growth and maintenance of your bird's body. Protein can also serve as an energy source but it is a far less efficient and more expensive source then carbohydrates or fats. There are 10 essential amino acids for birds including lysine, methionine, arginine, histidine, tryptophan, threonine. leucine, isoleucine, valine, and phenylalanine. Quality and bioavailability are important factors in evaluating protein sources. The quality varies with the number and amount of essential amino acids. The bioavailability or biologic value refers to the amount of a protein the animal actually utilizes versus that amount which is simply excreted in feces or urine.
Carbohydrates and fats provide energy to the body. Carbohydrates are usually classified into soluble and insoluble. Soluble carbohydrates are more easily digested, while insoluble carbohydrates resist digestion. Soluble carbohydrates provide energy and make up much of the foods fed to birds. Excess carbohydrates are stored as glycogen or fat for later use. Insoluble carbohydrate is also known as fiber. Fiber can act to affect gastrointestinal function; it can be used to treat both diarrhea and constipation. Fats serve to allow absorption of fat soluble vitamins such as A, D, E and K, enhance palatability and provide essential fatty acids. Birds have a dietary requirement for linoleic acid. These essential fatty acids act as components in cell membranes and are important for synthesis of other compounds such as prostaglandins.
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