Can you feed koi carp bread?

Bread can occasionally be offered to koi carp alongside their regular feed, with a few precautions.

Bread does not meet the nutritional needs of koi carp. Although it contains plant protein (around 9%), this is far from sufficient; some of that protein is gluten, which is insoluble and indigestible.

Its high carbohydrate content (around 50%) may also cause metabolic disorders, such as liver degeneration associated with excess glycogen.

Bread provides some vitamins (A, B, C and E), but much less than feed formulated for koi carp.

Wholemeal bread rather than white bread

According to Mark Davies (La grande encyclopédie des fascinants koi, Chantecler), white bread should be avoided because it may contain aluminium sulphate, described as a bleaching additive and chronically toxic to koi carp.

Soft bread rather than hard bread

Hard bread can injure the mouth. Soft bread is therefore preferable; otherwise, soak hard bread in water first.