odstepodstepenglishodsteppolski

Agrotechnika i weterynaria

AKADEMIA ROLNICZA -  WROCŁAW

Prof. dr M. Mazurkiewicz

 

The effect of DINO-96 preparation on selected immunity parameters in chicken following vaccination with LIVACOX T

 

Introduction

lmmunoprophylaxis in coccidiosis has played an important role in a large-scale production of reproductive and commercial flocks in the past years. The aim of the studies was to assess the usability of DINO-96 preparation in the increase of immunological response in birds immunised with Livacox T vaccine.

The experiment was carried out on 90 Astra S birds kept on the floor. The birds were divided into 3 equal groups, each with 3 subgroups. At the age of 10 days birds were immunised with Livacox T. The groups were as follows:

- Group l DINO-96 Poland; 0,6 g./kg of feed during the whole period of rearing

- Group II - birds immunised with Livacox T

- Group III - Amprol plus (133 ppm) for the whole period of rearing

 

Materials and methods

In the 6th, 12th and 16th week of the experiment selected indices of humoral and cell-mediated immunity were determined by a blastic transformation test using Con A and LPS mitogens, NBT test and chemoluminiscence, defining neutrophii phagocytosis. A histometric analysis of epithelium of duodenum, jejunum, leum and caecum was performed as well. The levels of IgG of E.acervulina

and E. tenelfa antibodies were defined by ELISA test.

Histological preparations of specimens collected from duodenum, jejunum, ileum and caecum were

made in the same weeks as above.

By a direct immunofluorescence method, using CD4 and CD8 monoclonal antibodies (Southern Biotechnology Assodates, England) as well as immunohistochemical method, sub-populations of T lymphocytes were determined in the preparations in the area of intestinal villi (along their length) and within intestinal glands (body and fundus of intestinal gland). Birds were also infected with a mixed culture of invasive oocysts of E. acervulina, E. maxima and E. tenella.

 

Results

Performing a blastic transformation test in the birds receiving DINO-96 preparation, the growth of lymphocyte proliferation, stimulated by LPS and Con A, was shown.

However, the values obtained in the control groups were not statistically significant. The results of NBT and CHL tests - the growth of neutrophii phagocytosis, were not statistically significant either.

The histometric anaysis of epithelium of intestinal villi and gland epithelium in all segments of the intestines showed a significant decrease in the number of enterocytes in Group II (immunised with Livacox T) and in Group III (birds recemng a coccidiostatic). On the other hand the increase in the number of enterocytes was observed in Group l (DINO-96 preparation). This group had also the increased number of mucous cells (goblet cells) and migrating cells (lymphocytes and neutrophilic granulocytes), which pointed to the preparation as a strong imunomodulator. The same pattern was recorded in the 6 th, 12th and 16th week of the experiment.The level of E. acervulina and E. tenella antibodies, determined by ELISA test, increased with the birds' agę. Moreover, on the dates of the challenge tests, it was markedly higher in Group l than that in the control groups. We atso found out that birds' age was correlated with the increase in the number of T lymphocytes in the segments of the digestive tract studied of both sub-populations. On the dates of the tests CD8 lymphocytes exceeded the number of CD8 ones. Generally, a very high increase in the level of CD4 and CD8 lymphocytes was observed in the group with DINO-96 preparation. Also the results of the experimental infection pointed to the effect of the preparation tested on the reduction of lesion score in the digestive tract of the birds infected with Eimeria sp.

 

Conclusion

  1. In the light of the experiment performed, DINO-96 preparation applied for the whole period of the rearing at the dose of 0,6 g./1 kg of feed activated strongly an intestinal lymphatic system (GALT), increased the immunity of the birds to the expehmental infection with invasive oocysts of coccidia and showed statistically insignificant jncrease in the proliferation of the limphocytes of peripheral blood as well as the growth of neutrophii phagocytosis.

  2. The results obtained speak for further studies on the preparation at research centres both borne and abroad (e.g. University of Munich or Higher School of Veterinary Medicine in Hannover).