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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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