In the conditions of the Republic of Belarus there were analyzed the peculiar features of morphology of bursa of Fabricius of turkeys broad-breasted white turkeys at the stage of postnatal ontogenesis. Research results showed that postnatal ontogenesis of bursa of Fabricius of turkeys developed irregularly with preservation of organ up to 220 days. At turkeys in 300-day old age the organ preserved only in 45% of bird units. Form, colour and consistency of bursa of Fabricius depended on bird age. The absolute weight of the organ increased up to 220 days. The relative weight was maximum at 20-day old age. The sexual peculiar features of the organ morphology were insignificant; they revealed after the beginning of sexual maturity and expressed by some difference in weight and linear dimensions.

As a result of realized in the conditions of the Republic of Belarus research it was revealed that application of immunostimulative drugs of sodium thyosulphate and vitamin С (ascorbic acid) in combination with a vaccine against salmonellosis, pasteurellosis and streptococcosis of pigs promoted the statistically authentic increasing of leukocytes, absolute quantity of T- and B-lymphocytes content in peripheral blood. Also, it promoted the activation of phagocytic activity and digested ability of neutrophils; activization of mieloblastic hemopoiesis and decreasing of erythrocytopoiesis; activization of morphological reactions in a tissue at a place of administration of the vaccine, lymphatic nodules and spleen. | Проведенные исследования показали, что применение иммуностимуляторов натрия тиосульфата и витамина С с вакциной против сальмонеллеза, пастереллеза и стрептококкоза свиней способствует статистически достоверному повышению в периферической крови содержания лейкоцитов, абсолютного количества Т- и В-лимфоцитов, активизации фагоцитарной активности и перевариваемой способности нейтрофилов; активизации миелобластического кроветворения и снижению эритропоэза; активизации морфологических реакций в ткани на месте введения вакцины, лимфоузлах и селезенке.