4Trust K A,Miller M W, Ringelman J K, et al. Effects of ingested lead on antibody production in mallards (Anas platyrhyncbos) [J]. J Wildl Dis,1990,26(3) :316-322.
5Youssef S A,El Sanousi A A, Afifi N A, et al. Effect of subclinical lead toxicity on the immune response of chickens to Newcastle disease virus vaccine [ J ]. Res Vet Sci, 1996,60 (1) :13-16.
