Mutual Influence Of Coccidial Infection And The Immunization Of Newcastle Disease And Avian Influenza

Chicken coccidiosis, Newcastle disease and avian influenza are three important diseases of chickens, and now, the vaccine has become an important measure for preventing these diseases. To study the mutual influence of coccidial infection and the immunization of Newcastle disease and avian influenza, in this paper, via detecting the Newcastle disease (ND) or avian influenza (AI) antibody titer, clinical symptoms, mortality rate, relative growth rate (RWG) and intestinal lesion score in SPF chicken inoculated with chicken coccidia precocious vaccine, vaccine of Newcastle disease and avian influenza vaccine immunization or attacked by chicken coccidia virulent, we studied the effect of chicken coccidiosis inactivated vaccine on the immunization Newcastle disease and avian influenza, effect of chicken coccidiosis on Newcastle immunity, effect of Newcastle disease vaccination against chicken coccidiosis immunity, and effect of chicken coccidiosis on the immune effect of avian influenza, respectively. The results show that(1). Compared with that of non-immune groups (groups N and NI), Newcastle HI titer of immune group with coccidium vaccine (NEI group) had no significant difference at 7 d after first immunication with ND (P>0.05), increased significantly (P<0.05) after 14 d after first immunication (7 d after second immunication with coccidium vaccine), which indicated that the chicken coccidiosis attenuated live vaccine has no obvious adverse effects on immune efficacy of Newcastle disease vaccine, and can increase the titer of antibody of Newcastle disease vaccine appropriately.(2). Compared with group N un-infected with coccidian, at 21 d after first immunication with ND, group NI infected coccidian virulent has a significantly decreased Newcastle disease HI titer (P<0.05), however, group NEI infected coccidian virulent and coccidiosis vaccine has no significant difference (P >0.05), which indicated that coccidian virulent can decrease the effect Newcastle disease vaccine immunity.(3). At 7 d after challenged with coccidian virulent strain, compared with those in group EI (inoculated coccidiosis vaccine), the difference of the average body weight, weight gain, relative growth rate and intestinal lesion scores in group NEI (inoculated coccidiosis vaccine and Newcastle disease vaccine) were significant (P>0.05), which indicated that Newcastle disease immunization has no obvious effect on the immune effect of coccidian precocious vaccine.(4). Compared with that of avian influenza immunization group (group A), the AIV HI of group inoculated avian influenza and coccidiosis vaccine (group AE) had no significant difference (P>0.05) at 35,49 d, increased significantly at 63 d (P< 0.05), which showed that chicken coccidiosis attenuated live vaccine has no obvious adverse effects on the immune effect of avian influenza vaccine, and can increase the antibody titer of avian influenza vaccine appropriately.(5). After immunization with avian influenza vaccine, the antibody titer of avian influenza in both groups infected coccidiosis virulent strain group (groups AI and AEI) and non-infection group (group A2) showed the increasing trend along with the increase of chicken age; the avian influenza antibody level of groups AI and AEI had no significant difference (P>0.05) with group A2 in the same age, which stated that the effect of avian influenza immunization were not affected by coccidiosis virulent.