EN
Introduction and objective. The objective of this study was to determine the effect of per os administration of 3 various dosages of a Citrosept preparation (a grapefruit extract)to growing turkey hens on changes in their selected haematological and immunological blood indices. An attempt was also undertaken to select the most efficient dose of the preparation with respect to the mentioned indices in turkey hens. Materials and methods. The experiment was conducted on 180 turkey hens allocated at random to 4 groups, 45 birds in each group. Samples of their full blood were analyzed for haematological indices, such as red blood cell count (RBS), haemoglobin content (Hb), haematocrit value (Ht), and white blood cell count (WBC). Samples of blood plasma were assayed to determine the activity of lysozyme (chamber-diffusive method) and heterophils capability to reduce nitro blue tetrazolium (stimulated and spontaneous NBT test). Phagocytic activity of leucocytes against Staphylococcus aureus 209P strain was assessed and expressed as the percentage of phagocytic cells (% PC) and phagocytic index (PI). Results. The administration of the grapefruit extract to turkey hens with drinking water caused a significant increase in haemoglobin content in blood, as well as an increase in non-specific humoral immunity marker (activity of lysozyme) and non-specific cellular immunity marker (percentage of phagocytic cells; P ≤ 0.05). Conclusions. The results obtained enabled the positive evaluation of the advisability of applying the Citrosept preparation in the feeding of turkey hens at the age of 6–9 weeks. Among the doses examined, the most efficient with respect to the stimulation of the non-specific humoral and cellular immunity was the dose of 0.021 ml/kg of body weight.