The results of hematological studies have shown that the blood of all animals tested was within physiological norms, which indicates normal clinical condition of the animals and the optimal course of biochemical processes.

When studying the concentration of total protein and its fractions in the blood serum of experimental pigs on the 90-th day of the main period of experience revealed a small increase in the 2-nd, 3 rd, 4-th and 5-th experimental groups 10.9, 6.2 (P<0.05), 6.0 (P<0.05) and 8.8 % (P<0.05), respectively. On the 150th day of the main period of experience, the content of total protein in the blood of pigs of 3rd experimental group was significantly higher by 11 % (P<0.05) than of the control group. In animals of the 2nd, 4th and 5th experimental groups a tendency to increase the total protein content in serum 7.7, 6.8 and 6.5 % respectively to the control was observed but the difference was not significant.

The increase of total protein in the serum of pigs related to the activity of aminotransferases, because these enzymes reflect the functional state of the liver and  are involved in the processes of transamination.

The use of Protecto-Active and Maceraza in feeding pigs experienced tread, contributes to the increase in aspartate aminotransferase activity in the range from 0.63 to 0.75 mmol/l×h (P<0.05) on the 90th day of the main period of the experience and from 0.69 to 0.79 mmol/l×h(P<0.05) on the 150th day. The activity of alanine aminotransferase was also increased in the range from to 1.24 to 1.41 mmol/l×h on 90th day of the basic period and between 1.50 to 1.64 mmol/l×h on the 150th day of the experience.

However, it should be noted that the average content of total protein and its fractions in blood serum AsAT and AlАТ in all groups were within physiological norms, which may indicate a harmless effect of study preparation on the animal.

The results of biochemical studies of blood indicate the likely increase of glucose level in blood serum on the 90th day of the main period of the experience in pigs of the 4th and 5th experimental groups, respectively, 13.6 (p<0.05) and 18.2 % (p<0.05), and in the animals of the 2nd and 3rd experimental groups, this rate was, respectively, at the level of 2.5 mmol/l, although the significant difference was not detected. On the 150th day of the experience the increased levels of glucose in serum were observed in pigs of the 3rd and 4th experimental groups, respectively 15.2 (P<0.05) and 12.1 % (P<0.05), whereas in the blood of the animals of the 2nd and 5th experimental groups, the glucose concentration increased respectively by the same amount and reached the level of 3.6 mmol/l, which was 9.1 % more than the control group.

The content of Calcium in the serum of pigs of the 2nd, 3rd, 4th and 5th experimental groups on the 90th day of the main period of the experience was higher, respectively, 4.5 and 9.1 %, than in control. On the 150th day of the experience Calcium in experimental groups increased and was higher than the control 14.3-19.0 %.

On the 90th day of the main period of the experience, the content of inorganic Phosphorus in the serum of all groups of pigs was at the same level (1.2 mmol), whereas on the 150th day of the amount of Phosphorus in the blood increased to 1.5-1.8 mmol/l.

So, it can be noted that all changes of biochemical parameters of blood, in addition to corresponding changes in the amount of glucose were not statistically significant and did not extend beyond the physiological norms, although there was a trend to increasing levels of Calcium and Phosphorus in blood serum.

Feeding pigs on Protekto-Active and enzyme preparation Maceraza do not have any negative impact on blood biochemical parameters. The pigs of the experimental groups showed a slight increase in the concentration of total protein, glucose, Calcium and Phosphorus in serum and contributed to the increase in the activity of AsAT and AlAТ compared with the control group. It should be noted that these figures do not go beyond the physiological norms.

Key words: pigs, forage mix, probiotic Protekto-Active, Maceraza, blood biochemical parameters.