EFFECT OF VITAMIN D3 ON BLOOD CELLS MORPHOLOGY AND INNATE IMMUNITY OF LAYING HENS
V. Y. Hudyma, I. V. Vudmaska
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Institute of Animal Biology NAAS, Stus st., 38, Lviv, 79034, Ukraine
Vitamin D is involved in the metabolism of bone and regulates calcium homeostasis in the body. In recent years, knowledge of its role has expanded considerably; particularly regulatory effect of vitamin D on the immune system has been identified. Content of vitamin D3 in the standard compound feeds for laying hens varies within 2.5–3.5 thousands IU/kg. An experiment on three groups of laying hens Hisex Brown cross was carried out. Hens fed diet with vitamin D3 addition in doses of 2500, 5000 and 10000 IU/kg during 30 days.
Increase of vitamin D3 content in the hens diet from 2500 to 10000 IU/kg significantly elevated the of 25-OH D3 concentration in the serum (from 15.10 to 27.25 ng/ml). A dose of 5000 IU/kg did not affect the concentration of 25-OH D3 (16.56 ng/ml). Rising the vitamin D presence in diet increased the red blood cells number and the concentration of hemoglobin in the blood (p<0.05) and reduced the number of leukocytes. In the blood of hens received a diet with high amount of vitamin D a greater number of monocytes and neutrophils were found. Particularly significant effect was observed for monocytes, which part in blood of 2nd group hens have been increased in 1.2 and in 3rd group in 1.6 times (p<0.01) compared to chickens of 1st group. Part of lymphocytes in the leukocytes of 1st, 2nd and 3rd groups blood were respectively 58.95; 54.57 and 48.26 %. Supplementation of diet with 10000 IU/kg of D3 increased phagocytic activity (p<0.05) in the blood of hens, what agreed with an increase in the number of monocytes and neutrophils. Bactericidal activity of serum in 2nd and 3rd groups (5000 and 10000 IU/kg D3) was 20 % higher (p<0.05) than in 1st group (2500 IU/kg D3). Thus, vitamin D3 enhanced the innate immunity of hens. The increase of vitamin D3 in the laying-hens diet to 5000 and 10000 IU/kg did not affect the egg productivity.
Keywords: LAYING HENS, VITAMIN D3, 25-OH D3, RED BLOOD CELLS, HEMOGLOBIN, WHITE BLOOD CELLS COUNT, INNATE IMMUNITY