Dose-Dependent Effects of Walnut Leaves on the Immunobiological Status and Productivity of Breeding Flock Hens

Goal. To determine the dose-dependent effect of dried walnut leaves (Juglans regia L.) on indicators of nonspecific resistance, blood morphology, and productivity of parent flock hens of the Birkovska Barvysta breed during the intensive egg-laying period. Methods. The study was conducted in 2024 at the experimental farm of the State Research Station for Poultry Farming of the Institute of Animal Husbandry of NAAS (SRS PF IAH NAAS) using the following methods: hematological (to assess hemoglobin content, erythrocyte and leukocyte counts in poultry blood), immunological (to determine phagocytic activity, the phagocytic index, serum bactericidal activity, and the level of circulating immune complexes), zootechnical (to determine the age at the onset of egg-laying, hen productivity, its intensity, egg weight, and flock survival rate), mathematical and statistical (to estimate means, standard errors, and the significance of differences between groups). Data analysis was performed using Microsoft Excel 2010. Results. The best immunobiological response was obtained when a 1.0% phytosupplement was added to the poultry diet. In this case, the phagocytic activity of the birds’ pseudo-eosinophils reached 59.4%, which was 6.1% higher than the control; the phagocytic index was 5.20 units; and the bactericidal activity of blood serum was 58.14%. When the dose of walnut leaves was increased to 1.5%, the phagocytic activity decreased to 52.0%, while levels of circulating immune complexes showed a tendency to increase. Hematological parameters did not indicate any negative effect of the supplement on blood morphology. When 1.0% walnut leaves were added to the diet, the hemoglobin level was the highest — 130.04 g / L — the erythrocyte count remained stable, and the total leukocyte count was significantly lower compared to the control group. The hens’ productivity indicators were also the best at this supplement level: egg production per initial laying hen exceeded that of the control group by 10.8%, egg-laying intensity by 6.1 percentage points, average egg weight by 1.8%, and flock survival rate was 99.0%. Conclusions. The effect of dried walnut leaves on the hens’ organism was dose-dependent. The greatest effect was observed when the supplement was administered at a rate of 1.0% of feed weight, which ensured a combination of activation of the cellular and humoral components of nonspecific resistance, a favorable hematological profile, and increased poultry productivity. Increasing the supplement dose to 1.5% did not produce any additional positive effect and was accompanied by signs of a less favorable immunobiological response. The results obtained confirmed the advisability of using 1.0% dried walnut leaves in compound feed to maintain the natural resistance and productivity of the parent flock.