Because the digestive tract of newborn piglets is physiologically undeveloped, they reluctantly begin to consume full-feed in the first two weeks of life. Sows’ colostrums can not satisfy the needs of piglets in nutrients and essential microelements during the whole suckling period, which leads to the reduction of their natural resistance. Thus, lack of Ferum in piglets can be observed since the 5-7th day and proceeds to its maximum development at 3 weeks of age.  At the age of 5–7 days they receive 1 mg with mother's milk while daily requirement is 7–10 mg. By three weeks of age piglets need up to 114–200 mg of Ferum, but they get only 23–24 mg with the milk.

Lack of Ferum in the body of piglets flukes leads to iron deficiency anemia. Cuprum strengthens the mobilization of deposited iron to the marrow, and the lack of Zinc in the diet of piglets leads to the changes in the epidermis.

The use of immunostimulatory drugs of thymus normalizes the protective body functions.

The aim of the study was to find out the effects of the drug thymus on morphological indicators of peripheral blood, the main content of microelements in the peripheral blood serum, survival and productivity of piglets.

Animals in each nest were divided into control and experimental groups of 12 heads in each one. The animals of the control group on the 2nd day after the birth were injected the isotonic NaCl at a dose of 1 ml/kg and iron drug "Ferovit" at a dose of 1 ml/kg for the prevention of nutritional anemia.

Piglets in experimental group once on the 2 nd day after birth were injected immunostimulatory drug thymus  in the inner surface of the pelvic limb  at a dose of 1 ml/kg body weight and “Ferovit” at a dose of 1 ml/kg on the inner side of the pelvic limb. Both groups were re-injected 1,5 ml "Ferovit" on the 7 th day. Control group of pigs again was injected sodium chloride and experimental animals were injected thymus drug at a dose of 1 ml/kg body weight.

The time which the piglets stey the sow was divided into three periods: I – from 5 to 14; II – from 14 to 28; and III – from 28 to the 45th day. During the experiment the piglets eating mixed fodders were observed. The mixed fodders were given starting from the 5th day of life. On the 45 th day before weaning peripheral blood was selected to prepare the serum from it and to determine in it: Fe, Zn, Cu.

It was found that as a result of incomplete consumption of mixed fodders in the first, second and third periods, respectively 75, 92 and 99 % the deficit of mentioned above substances in the diet was observed. Provision of pigs’ organism for 1, 2 and 3 periods of cultivation amounted: Ferum – to 114,6; 104,2 and 100,5 %; Cuprum – respectively 80,8; 100,0 and 98,8 %; Zinc – 77,9; 98,1 and 97,0 %. On the 14th day it was found that in the peripheral blood of piglets from experimental group, which was injected drug thymus and "Ferovit” hemoglobin concentration was by 4.4% higher and the number of red blood cells by – 14,7 % higher than in the control group of animals (P<0,05). In addition, the increase in hematocrit value by 1,59 % in piglets from experimental group compared with controls (P<0,05) was observed.

Later, on the 28th and 45th day the increase in the concentration of hemoglobin respectively by 6,1 % (P<0,05) and 3,4 % was observed, erythrocyte count increased respectively by 10,2 and 4,1 % (P<0,05) compared with control. During this period, an increase of hematocrit values in piglets’ blood respectively by 3,1 and 2,5 % (P<0,05) was noted too.

It was found that the serum of animals of the experimental group on the 45 th day contained Ferum, Zinc and Cuprum respectively by 36,3; 31,1 (P<0,05) and there was 9,8 % increase over the content of these substances in the blood of animals of the control group.

The total live weight of piglets’ nest in the experimental group at weaning on the 45 th day was 155,4 kg and in the control group – 129,1 kg. The average live weight of 1 head in the experimental group was 14,13±0,37 kg, in control group –12,91±0,52 kg, which is by 1,22 kg, or 8,6 % more than (P<0,01). In the control group of pigs daily gain in 45 days was 265 g, and in the experimental group – 289 g, which by 9,3 % more than in the control group.

The simultaneous use of drug thymus with Feravit for piglets in production environment in a dose of 1 ml/kg body weight contributed to improving the survival of piglets by 8,3 % and increasing of average daily live weight gain by 28g.

Key words: stress, adaptation, biotic elements, blood’s serum, Ferum, Zinc, Cuprum, productivity, survival, piglet.