Ducks require almost twice the amount of niacin or vitamin B3 then what is required for chickens. This increased requirement is related to their inability to synthesize niacin from tryptophan efficiency, resulting from the presence of high amounts of enzyme, picolinic acid carboxylase in the liver.
Table 1: Picolinic Acid Carboxylase Activity in Different Species
|Species||Units/g Liver (wet basis)|
|Table Adapted from Scott et al. (1982)|
Causes of Niacin Deficiency
Ducklings are at risk of niacin deficiency if they are fed a poor quality diet which does not provide enough niacin, such as feed intended for chickens.
Niacin Deficiency Symptoms
Clinical signs of niacin deficiency in ducklings vary depending on the severity of the deficiency. Most typical signs include bowed legs and/or enlarged hock joints. These birds will ultimately become so crippled and weak that they cannot walk.
Dietary Sources of Niacin
Niacin is widely distributed in feedstuffs of both plant and animal origin. The best food sources of niacin include distiller’s grains, Brewer's yeast, beets, fish, various distillation and fermentation solubles, sunflower seeds, and certain oilseed meals. The availability of niacin in grain and grain by-products is very low. Other sources of niacin include tablets or capsules in both regular and timed-release forms.