jamie
Rollerblading along the road
- Joined
- 10/16/09
- Messages
- 2,036
- Real Name
- Jamie
I summarized some of the information from the following journal article:
"Nutrition of Birds in the Order Psittaciformes: A Review" by Elizabeth A. Koutsos, Kevin D. Matson, and Kirk C. Klasing. Originally published in the Journal of Avian Medicine and Surgery Volume 15 number 4, pages 257-275, 2001.
I included information from other sources I have read as well as a couple of web sites.
Protein
What is it?
Proteins are complex molecules made up of amino acids. The amino acids are linked together into long chains and folded to form complex shapes. The chemical makeup of proteins as well as their geometry determine how a bird's body will use them. Proteins are used to build skin, muscle, feathers, repair organs, aid in metabolism and other biological processes in a bird's body. Consequently, protein is a very important part of a parrot's diet.
What are amino acids?
Amino acids are compounds made up primarily of nitrogen, hydrogen, carbon and oxygen. They are literally the building blocks of proteins and the building blocks of a bird's body. There are 20 different naturally-occurring amino acids and they are divided into two groups- essential and non-essential. A bird's body can synthesize non-essential amino acids while it must obtain essential amino acids from food. Of the 20 amino acids, there are 9 that are essential for birds:
arginine
isoleucine
leucine
lysine
methionine
phenylalanine
valine
tryptophan
threonine
Three others: Glycine, histidine, and proline are generally considered to be essential because research in chickens indicates that birds can not synthesize these compounds quickly enough to meet metabolic needs. (Koutsos, 2001). If a bird's diet lacks one or more of these essential amino acids, they can have major health problems.
How much protein do birds need?
This is a complex question and it varies by species as well as the stage in the bird's life. Generally, birds require a higher percentage of protein in their diet just after they hatch and are growing. As they age, their protein requirements drop. However, breeding birds and molting birds require slightly more protein. Here is some information summarized in a journal article and based on several different studies (Koutsos, 2001):
Species Physiological State Protein Level
Budgerigar maintenance 6.8%
Budgerigar maintenance 12%
Budgerigar egg production 13.2%
Budgerigar growth 13.2%
Cockatiel maintenance 11%
Cockatiel growth 20%
African Grey maintenance 10-15%
Rainbow Lorikeet maintenance 2.9%
So, as you can see the amount of protein required by a healthy bird varies greatly from species to species as well as by physiological state. Also, the various studies indicate that the type of protein available also has an impact on the percentage required in the bird's diet. Some proteins are more difficult for birds to digest so their diets have to contain higher amounts than would be required if the protein source was more easily digested. For example, the study on Rainbow Lorikeets indicated that the birds required a diet consisting of only 2.9% protein- when the protein source was egg whites, an easily digestible source of protein. In the wild, lorikeets get the majority of their protein from pollen which is more difficult to digest so their diets contain significantly more protein that the study suggests.
Can they have too much protein?
This is also a complicated question. Many reference books and other sources of information will say that high levels of protein can cause things like kidney problems and gout in parrots. However, there is not a lot of scientific evidence to back up these claims. Koutsos (2001) summarizes a study (http://jn.nutrition.org/cgi/content/full/131/7/2014) on adult male cockatiels who ate diets of 20%, 35% and 70% crude protein for 11 months and suffered no visible signs of protein toxicity, kidney problems or gout. The birds who ate a diet consisting of 70% crude protein did experience hepatic sinusoidal and periportal lipogranulomas which might indicate liver damage caused by a diet unreasonably high in protein. This study is also referenced on Roudybush's web site:
http://roudybush.com/index.cfm?fuseaction=home.faqResults&group_id=5 "Q: I have heard that processed foods cause kidney disease in birds. Is this true?
A: There are many misconceptions about this issue in birds. Tom Roudybush participated in a study at UC Davis in 2000/2001 in which normal grey cockatiels were fed diets with up to 70% protein for one year. No clinical signs of kidney disease were seen. The kidneys were examined microscopically at the end of the experiment and no significant abnormalities were found. Toxic levels of Calcium and Vitamin D3 may cause kidney damage, and kidney problems may be an inherited defect being bred into lines of color mutation birds. Until more information is available in psittacines, Roudybush, Inc. advises bird owners and breeders to exercise common sense and feed their birds diets that lie within safe ranges (safe from both deficiency and toxicity) based on research performed in any avian species studied so far, including poultry. Don?t feed your birds a deficient diet in order to protect the few birds that might have an underlying kidney malfunction."
What are "complete" proteins?
A complete protein source contains all of the essential and non-essential amino acids. It is a "complete" source. Some good examples of naturally occurring complete proteins are egg whites, soy beans, quinoa, and meat. However most of us do not feed our birds any meat. A good commercial parrot pellet will contain all of essential and nonessential amino acids and is a complete source of protein for parrots. For example, Harrison's Adult Lifetime Coarse pellets contain a minimum of 15% crude protein which is within the acceptable range given above for maintaining a healthy adult bird and nowhere near the unreasonably high levels used in the cockatiel study mentioned earlier (http://www.harrisonsbirdfoods.com/products/al.html). When considering any diet for your bird, you should examine the nutritional content of the food you are providing to determine whether or not it will give your bird all of the essential amino acids it needs.
This can be a problem with seed mixes. Birds will pick and choose their favorite seeds from a mix and, consequently, may end up with a nutritionally deficient diet as a result- even if the nutritional informatin on the package indicates the mix contains all of the proteins & nutrients the birds need. This is one reason that many parrot owners opt for feeding their birds a pelleted diet supplemented with fresh fruits and vegetables- or some other diet that will ensure the birds get a healthy diet in spite of their pickiness.
"Nutrition of Birds in the Order Psittaciformes: A Review" by Elizabeth A. Koutsos, Kevin D. Matson, and Kirk C. Klasing. Originally published in the Journal of Avian Medicine and Surgery Volume 15 number 4, pages 257-275, 2001.
I included information from other sources I have read as well as a couple of web sites.
Protein
What is it?
Proteins are complex molecules made up of amino acids. The amino acids are linked together into long chains and folded to form complex shapes. The chemical makeup of proteins as well as their geometry determine how a bird's body will use them. Proteins are used to build skin, muscle, feathers, repair organs, aid in metabolism and other biological processes in a bird's body. Consequently, protein is a very important part of a parrot's diet.
What are amino acids?
Amino acids are compounds made up primarily of nitrogen, hydrogen, carbon and oxygen. They are literally the building blocks of proteins and the building blocks of a bird's body. There are 20 different naturally-occurring amino acids and they are divided into two groups- essential and non-essential. A bird's body can synthesize non-essential amino acids while it must obtain essential amino acids from food. Of the 20 amino acids, there are 9 that are essential for birds:
arginine
isoleucine
leucine
lysine
methionine
phenylalanine
valine
tryptophan
threonine
Three others: Glycine, histidine, and proline are generally considered to be essential because research in chickens indicates that birds can not synthesize these compounds quickly enough to meet metabolic needs. (Koutsos, 2001). If a bird's diet lacks one or more of these essential amino acids, they can have major health problems.
How much protein do birds need?
This is a complex question and it varies by species as well as the stage in the bird's life. Generally, birds require a higher percentage of protein in their diet just after they hatch and are growing. As they age, their protein requirements drop. However, breeding birds and molting birds require slightly more protein. Here is some information summarized in a journal article and based on several different studies (Koutsos, 2001):
Species Physiological State Protein Level
Budgerigar maintenance 6.8%
Budgerigar maintenance 12%
Budgerigar egg production 13.2%
Budgerigar growth 13.2%
Cockatiel maintenance 11%
Cockatiel growth 20%
African Grey maintenance 10-15%
Rainbow Lorikeet maintenance 2.9%
So, as you can see the amount of protein required by a healthy bird varies greatly from species to species as well as by physiological state. Also, the various studies indicate that the type of protein available also has an impact on the percentage required in the bird's diet. Some proteins are more difficult for birds to digest so their diets have to contain higher amounts than would be required if the protein source was more easily digested. For example, the study on Rainbow Lorikeets indicated that the birds required a diet consisting of only 2.9% protein- when the protein source was egg whites, an easily digestible source of protein. In the wild, lorikeets get the majority of their protein from pollen which is more difficult to digest so their diets contain significantly more protein that the study suggests.
Can they have too much protein?
This is also a complicated question. Many reference books and other sources of information will say that high levels of protein can cause things like kidney problems and gout in parrots. However, there is not a lot of scientific evidence to back up these claims. Koutsos (2001) summarizes a study (http://jn.nutrition.org/cgi/content/full/131/7/2014) on adult male cockatiels who ate diets of 20%, 35% and 70% crude protein for 11 months and suffered no visible signs of protein toxicity, kidney problems or gout. The birds who ate a diet consisting of 70% crude protein did experience hepatic sinusoidal and periportal lipogranulomas which might indicate liver damage caused by a diet unreasonably high in protein. This study is also referenced on Roudybush's web site:
http://roudybush.com/index.cfm?fuseaction=home.faqResults&group_id=5 "Q: I have heard that processed foods cause kidney disease in birds. Is this true?
A: There are many misconceptions about this issue in birds. Tom Roudybush participated in a study at UC Davis in 2000/2001 in which normal grey cockatiels were fed diets with up to 70% protein for one year. No clinical signs of kidney disease were seen. The kidneys were examined microscopically at the end of the experiment and no significant abnormalities were found. Toxic levels of Calcium and Vitamin D3 may cause kidney damage, and kidney problems may be an inherited defect being bred into lines of color mutation birds. Until more information is available in psittacines, Roudybush, Inc. advises bird owners and breeders to exercise common sense and feed their birds diets that lie within safe ranges (safe from both deficiency and toxicity) based on research performed in any avian species studied so far, including poultry. Don?t feed your birds a deficient diet in order to protect the few birds that might have an underlying kidney malfunction."
What are "complete" proteins?
A complete protein source contains all of the essential and non-essential amino acids. It is a "complete" source. Some good examples of naturally occurring complete proteins are egg whites, soy beans, quinoa, and meat. However most of us do not feed our birds any meat. A good commercial parrot pellet will contain all of essential and nonessential amino acids and is a complete source of protein for parrots. For example, Harrison's Adult Lifetime Coarse pellets contain a minimum of 15% crude protein which is within the acceptable range given above for maintaining a healthy adult bird and nowhere near the unreasonably high levels used in the cockatiel study mentioned earlier (http://www.harrisonsbirdfoods.com/products/al.html). When considering any diet for your bird, you should examine the nutritional content of the food you are providing to determine whether or not it will give your bird all of the essential amino acids it needs.
This can be a problem with seed mixes. Birds will pick and choose their favorite seeds from a mix and, consequently, may end up with a nutritionally deficient diet as a result- even if the nutritional informatin on the package indicates the mix contains all of the proteins & nutrients the birds need. This is one reason that many parrot owners opt for feeding their birds a pelleted diet supplemented with fresh fruits and vegetables- or some other diet that will ensure the birds get a healthy diet in spite of their pickiness.
