Nutrition during moulting

02december2009
Source: The Waltham Book of Companion Animal Nutrition, Pergamon Press Ltd, 1993, foto: Rex (via Wikipedia)
Feathers consist of protein for 85-97 percent. And this protein consists almost entirely of keratin. Keratin is a tough, insoluble protein with a high percentage of sulphur-containing amino-acids. The disulfide bridges between the molecules create a solid structure.
During moulting - which can last 6 to 8 weeks and which in Western Europe usually occurs in late summer - the level of amino-acids and the make-up of the bird’s nutrition are important.
Especially the sulphur-containing amino-acids methionine and cysteine play a role. Cysteine is an important component of keratin, and methionine is a cysteine precursor. When a large amount of feathers needs to be produced, a maximal nutrition efficiency is reached if at least half of the sulphur-containing amino-acids in the diet is cysteine. After the moulting period, the value of cysteine is reduced.

During moulting, it is advised to offer seeds such as turnip and white millet, because these contain higher amounts of amino-acids.

Besides an increased protein requirement during moulting, a larger amount of energy is also needed. Birds that are bald have an 85% higher energy requirement than birds with normal feathering (at 22 degrees Celsius). Birds in moult can therefore use some extra energy in the form of oil-containing seeds.
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