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Many bird
keepers report problems with molting birds. Birds get "stuck in the
molt", molt slowly or produce poor quality feathers. Research carried
out at the Institute of Animal Nutrition at the Hanover School of
Veterinary Medicine shed some light on the nutritional requirements of
molting cage birds.
The researchers compared the molting performance of canaries by
dividing them into three groups and feeding them differently.
Group 1 was fed on: An un-supplemented seed diet
Group 2 was fed on: Seed plus a molting supplement high in calcium and
sodium
Group 3 was fed on: Seed plus a molting supplement high in calcium,
sodium, zinc and sulphur containing amino acids.
The supplements used were ones that were already on the market in
Germany. So that they could get as full a picture as possible of any
effect these diets may have on molting, the researchers looked at three
different features of the molt:
The time from individual feather loss to the first appearance of the
new feather (turnover time) .
The growth rate
of the new feather.
The time from the onset of the molt (shedding feathers) to
the completion of the molt.
Interestingly the results did not find that the supplements made any
difference to either of the first two features - the turnover time or
the feather growth rate. But the birds on no supplement or on the
second diet with a mineral only supplement were much more reluctant to
start the molt and they took longer to go through the molt as they shed
fewer feathers at any one time. It seems that the birds fed the sulphur
containing amino acid supplement were far quicker to go into the molt.
They dropped more feathers more quickly and so were able to go through
the molt faster.
There is a simple explanation for this. Feathers are mostly made of
protein and the proteins in feathers contain larger quantities of
sulphur containing amino acids than the protein in other parts of the
body. Seed-based diets are particularly low in these critical amino
acids. Since mineral only supplements do not compensate for this
shortage they did not prove adequate to promote a fast successful molt.
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