beta-carotene and Newcastle-Disease

Newly hatched Japanese quail (Coturnix coturnix japonica) chicks were fed diets containing different levels of retinoids (vitamin A) or beta-carotene. Group A received a commercial diet containing 10,000 IU vitamin A per kilogram. The diets of Groups B, C, and D contained no vitamin A but were supplemented with 1-, 2.5-, and 5-fold retinol equivalents of beta-carotene. Each group contained 16 quails in a 1:1 sex ratio. At 8 weeks of age the quails were immunized orally with Newcastle disease virus (NDV) vaccine according to the manufacturer's recommendations. Boosters were given three times at two-week intervals. Blood samples were taken at two-week intervals until 14 weeks of age. The anti-NDV IgY titre was determined by a locally developed direct enzyme-linked immunosorbent assay (ELISA). Groups A and B showed nearly the same antibody response. This indicates that the preformed vitamin A and the equivalent beta-carotene have the same immunomodulatory effect. Groups receiving higher doses of beta-carotene (Groups C and D) exhibited significantly higher plasma IgY levels compared to Groups A and B. The results indicate that elevated doses of beta-carotene have a slight effect on the adaptive immune response in Japanese quail.

Topics: Animals; beta Carotene; Coturnix; Dietary Supplements; Egg Yolk; Enzyme-Linked Immunosorbent Assay; Female; Immunoglobulins; Male; Newcastle Disease; Retinoids; Time Factors; Viral Vaccines