Modern approaches to the use of apitherapy in veterinary medicine and the effectiveness of comparative schemes of application of drone breed extract in vaccination of chicken against Newcastle disease

In the present article the study of immunostimulating effect of the developed immunostimulant - drone brood extract (DBE) on the body of chickens under different application schemes was carried out. The 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 received the extract together with vaccination, the third — 5 days before vaccination, and the fourth — 5 days after vaccination. The first group remained as a control group. Blood sera were examined by RZHA. Immunomorphological studies were carried out at macroscopic and microscopic levels and indices of the thymus, Fabricius' bursa, and spleen were calculated. According to the results of the study, it was established that the titer of antihemagglutinins in RZHA 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 4th group — 7.3 ± 0.12 log2 and in the 2nd 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 using the vaccine and DBE compared to the control. Positive changes were observed in the thymus index, which was 5.56 ± 0.014, 5.63 ± 0.13, and 5.51 ± 0.15 in the 2nd, 3rd, and 4th experimental groups, respectively. In the control group, this index 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, 5.46 ± 0.01 and 5.50 ± 0.01, respectively. Bursa indices also show the superiority of this indicator in the 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 of 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 spleen index