The therapeutic effect of Astragalus mongholicus on cryptosporidiosis in chickens.

To observe the therapeutic effect of Astragalus mongholicus(AM) on cryptosporidiosis in chicken,3 days old chicken was used for experiment and they were infected with 1×106 Cryptosporidium baileyi oocysts. Meanwhile,Astrali seu Hedysari Decoction (AHD) in a concentration of 1 g/mL was introduced in different amount (0.1 mL,0.2 mL ,0,4/mL to each chicken). The mental status,body weight,number of oocysts extracted daily,index of bursa of Fabricius (BF) and spleen of chicken were observed. The results showed that lower dose of AHD could lessen the clinical symptoms and reduce the incidence rate and mortality of chicken inoculated with C.bailleyi. In the low-dose treated chicken,the total amount of oocysts extracted was lower and the patent period was shorter. The indices of BF and spleen in the treated group of chicken were higher than the infected control group over 36.73% (P0.01) and 41.94% (P0.01),respectively. These results indicate that lower doses of AHD can improve the development of BF and spleen of chicken and enhance their immune responses,suggesting its selective and double regulatory effect in immune function,which may be related to the dose used.