Hematological indices of the laying hens under the influence of seleno, zinc nanochelates and vitamin E

Abstract

Introduction. The most sensitive system of the body in the changing supply of nutrients to the diet is the blood system. In addition to the protein and energy supply of the diet on the development of tissues and cells of the blood system, the availability of chemical elements has a significant impact. According to the reports of some authors, changes in the bird organism during hyposelenosis (Anikina & Nikitina, 2002; Volkova et al., 1994) reduced zinc and other trace elements content were identified and described (Dzhulay et al., 2000; Ivanova, 1990; Miroshnikov & Lebedev, 2006; Latshaw et al., 1977; Stahl et al., 1986). Using the complex of selenium, zinc and vitamin E nanoaquachelates as essential nutrients in different periods of laying hens, their long-term effects on hematological parameters in the bird organism were not found. For this purpose, we conducted experiments on laying hens in order to establish the reaction of the body and the effects of selenium, zinc and vitamin E introduced into the diet of birds.

The research aim was to study the effect of selenium, zinc and vitamin E nanoaquachelates on hematological parameters of laying hens of the Lohmann Brown breed.

Methods. The experiments were performed in the vivarium of the Company College of Veterinary Medicine on laying hens of the Lohmann Brown breed at the age of 40 weeks. According to the method of analogues, four groups of chickens were selected, with 20 heads in each group. The first group was the control group, and the 2^nd, 3^rd and 4^th groups were experimental. Bird I of the control group during the whole experiment received a basic diet, balanced by feeding standards, and nanoaquachelates of selenium, zinc with vitamin E in different doses were added to the laying of experimental groups to the diet. The study material was the laying hens blood of the Lohmann Brown breed. Blood sampling and laboratory tests (which determined the count of erythrocytes and leukocytes, hemoglobin content) were performed according to generally accepted rules and methods (Avdosieva et al., 2016).

Results and discussion. Changes in the blood system are known to be objective indicators that characterize the physiological state of an animal's living organism. In this case, the quality of nutrition has a significant impact on the hematological parameters of the animal and poultry. Therefore, we conducted a study of possible changes in the morphological composition of blood in the chicken with the feeding of these elements. It was found that the number of shaped elements and hemoglobin level were almost the same in the control and experimental groups before the experiment. However, during the course of the experiment, individual indicators changed. In particular, the number of erythrocytes in the blood of experimental chickens compared to controls increased significantly by the 60^th and 90^th days of the experiment by an average of 10.2–16.1 and 11.2–18.0 %, respectively, and the number of leukocytes was unlikely changes and was within normal limits. It should also be emphasized that changes in the erythrocytes in the blood of the experimental bird groups were likely, indicating the activation of erythrocytopoiesis by exposure to selenium and zinc nanochelates, which are essential elements.

Therefore, the chelates of selenium and zinc with vitamin E positive effects can be noted on the processes of hematopoiesis, as evidenced by the increase in the concentration of hemoglobin in the blood of experimental chickens compared with control. The hemoglobin content of experimental chickens compared to controls during the experiment probably increased only on day 60 in the group of chickens treated with Selenium with vitamin E – by 2.10 % and in chickens treated with Zinc with vitamin E – 2.64 %. In animals that were supplemented with Selenium with Zinc and Vitamin E, 4.96 %. On the 90th day of the experiment the probable increase in hemoglobin level by groups was: group II – 3.44 %; III – 4,55; zinc and IV – 8,65 %. The established results of the researches testify to the positive effect of both the separate feeding of the applied nanoaquachelates with vitamin E and their complex application on the level of hemoglobin in the blood of the laying hens. The study of leukocyte counts in laying hens showed a slight increase, and in some animals, on the contrary, a decrease in the number of this indicator. However, such fluctuations were not probable, and therefore it is impossible to deduce any regularity and to speak about the depressive or stimulating role of the effect of drugs on leukocytopoiesis. Feeding zinc and selenium nanochelates with vitamin E in laying hens did not cause negative changes in the blood picture, and the increase in red blood cells in the test hens was within physiological limits and promoted a probable increase in hemoglobin content in the laying hens.

Our regularities are explained by researches of many authors. It is emphasized that selenium compounds stimulate the functional activity of the hematopoietic system and regulate pancreatic lipase synthesis and absorption of fat and vitamin E (Snitynskyi, 2006; Kudrin, 2007; Danchuk, 2006; Van Wouwe, Uijlenbroek, 1994). Zinc is also important. In particular, there is a relationship between zinc metabolism in the body and the state of individual functional systems (Krebs, 2000). Vitamin E with its inherent antioxidant properties plays an important role in the animal's system of protection.

Conclusions. Studies have shown that the addition of zinc and selenium nanochelates with vitamin E to the laying hens diet promotes the increase of red blood cells in the experimental hens by the 60^th and 90^th days of the experiment by 10.2-16.1% and 11,2–18.0 %, respectively. It was found that the hemoglobin content in the blood of experimental laying hens, compared with the control ones, probably increased on the 60^th and 90^th day of the study by 2.75–4.40 %. The greatest positive effect is shown by the feeding of the complex Se (30 ml/kg) + Zn (30 ml/kg) + vitamin E (40 mg/kg) per day. This demonstrates the positive effect of zinc and selenium nanochelates feeding along with vitamin E on such an important blood count as hemoglobin. In the future, the effect of zinc and selenium nanochelates with vitamin E on metabolic processes in the laying henы should be studied.