Apitherapy and immunostimulation of chicken with drone brood extract in vaccination against Newcastle disease under different schemes of application

In the presented article, the study of the immunostimulating effect of the developed immunostimulant - drone brood extract (DBE) on the body of chickens under different application schemes was carried out. Immune status was calculated based on serological and immunomorphological indicators. To determine the optimal scheme of DBE application, 3 experimental and control groups of 6 two-week-old chickens were formed. The second group was given the extract together with the vaccination, the third - 5 days before the vaccination, and the fourth - 5 days after the vaccination. The first group remained the control group. Blood sera were studied with the help of Hemagglutination inhibition assay (HI). Immunomorphological studies were carried out at the macroscopic and microscopic levels and indices of the thymus, bursa of Fabricius and spleen were calculated. According to the results of the study, it was established that the titer of antihemagglutinins in HI was higher in the 3rd group, where the immunostimulant was administered 5 days before vaccination and was 7.4±0.13 log2, this indicator was slightly lower in the fourth group 7.3±0.12 log2 and in the second group 7.2±0.12 log2. In the first group, the level of antihemagglutinins was 5.3±0.3 log2. The absolute mass of the thymus increased in the experimental groups when using the vaccine and DBE compared to the control. Positive changes were noted in the thymus index, which in the 2, 3, and 4th experimental groups equaled 5.56±0.014, respectively; 5.63±0.13 and 5.51±0.15. In the control, this indicator was lower and corresponded to 4.58±0.01. The Bursa of Fabricius index in the control group of chickens was equal to 4.26±0.012, and in the 2nd, 3rd and 4th experimental groups it reached 5.42±0.01, respectively; 5.46±0.01 and 5.50±0.01. Bursa indices also demonstrate the superiority of this indicator in experimental groups that received an immunostimulant. Mass indicators and spleen indices differed in the control and experimental groups. If in control chickens this indicator corresponded to 412.4±42.4 mg, then in subjects in the 2nd, 3rd and 4th groups it increased to 532.4±15.30; 598.2±17.2 and 542.8±33.4 mg. The same trend was observed in the change of the spleen index.