Niacin (Vitamin B3) is crucial for energy metabolism, converting the carbohydrates, fats, and proteins in feed into usable cellular energy through the coenzymes NAD and NADP. It plays an especially important role in leg health and joint development, making niacin deficiency one of the most common nutritional causes of leg problems in poultry. Growing chicks are particularly vulnerable because their rapid bone and joint development demands high niacin levels.
Niacin also supports healthy skin, a well-functioning digestive tract lining, and the nervous system. An interesting quirk of chicken biology: while most mammals can efficiently convert the amino acid tryptophan into niacin, chickens do this very poorly. Roughly 45 mg of tryptophan yields only about 1 mg of niacin in a chicken, compared to much better conversion rates in mammals. This means chickens are far more dependent on getting preformed niacin directly from their diet rather than synthesizing it from protein.
Corn-heavy diets are particularly risky for niacin status because corn is low in both niacin and tryptophan. Backyard flocks that receive heavy scratch grain supplementation (which is mostly corn and wheat) may dilute their niacin intake below adequate levels, even though they appear to be eating plenty.
Chickens need about 27 to 35 mg of niacin per kilogram of feed. Quality commercial feeds include adequate niacin. If you mix your own feed or offer heavy scratch grain supplementation, niacin can become limiting. Brewer's yeast sprinkled over feed (about a tablespoon per hen daily) is the classic poultry keeper's niacin trick, providing a generous boost along with other B vitamins. Sunflower seeds and peas are also good natural sources.
0.0% of daily nutrient intake
Vitamin B3 (Niacin) makes up 0.0% of your chicken's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Bowed legs and swollen hock joints especially in chicks, difficulty walking, poor feathering, inflammation of the mouth and tongue, diarrhea, reduced growth rate, failure to thrive, reduced egg production and poor hatchability in breeding stock
Niacin has a wide safety margin in poultry and excess is excreted readily since it is water-soluble. Toxicity from dietary sources is extremely rare. Even supplemental niacin at several times the recommended level is well tolerated.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 27 | 35 | mg/kg feed | Chickens convert tryptophan to niacin very poorly, so direct dietary niacin is essential. Corn-heavy diets risk deficiency. |
Source: NRC Poultry 1994; Merck Veterinary Manual
