Vitamin A status of wild mallards (Anas platyrhynchos) wintering in Saskatchewan.

Vitamin A status of wild male mallards (Anas platyrhynchos) overwintering in Saskatchewan, Canada was determined. Vitamin A levels < 0.2 micrograms hepatic retinyl palmitate/g liver, occurred in 6% and 25% of male mallards sampled in 1991 to 1992 and 1992 to 1993, respectively. There was no temporal trend in vitamin A levels over either winter. Squamous metaplastic lesions, commonly associated with vitamin A deficiency in domestic animals, were not observed in any bird; hence, they were not a good indicator of vitamin A status in wild mallards. Serum retinol was not a good indicator of vitamin A status in wild mallards. Many mallards in good body condition had low vitamin A levels; thus, we propose that good body condition and ample fat stores are not indicative of overall health of the bird.