5van HEUGTEN E, SPEARS J W, KEGLEY E B, et al. Effects of organic forms of zinc on growth performance, tissue zinc distribution, and immune response of weanling pigs[J]. Journal of Animal Science, 2003, 81(8): 2063-2071.
6PAYNE R L, BIDNER T D, FAKLER T M, et al. Growth and intestinal morphology of pigs from sows fed two zinc sources during gestation and lactation[J]. J Anita Sci, 2006, 84(8): 2141-2149.
7Carina P, Bianco I l),Correa S G.Local and systemic activity of the polysaccharide chitosan at lymphoid tissues after oral administration[M].Leukocyte Biology,2005 : 62-69.