In this work it was searched the influence of nanoparticles of cobalt and probiotic on the basis of genus Lactobacillus association on lipid per oxidation in chickens.

The research was carried out on 50 hens of cross Highsex Brown of meat and egg productivity direction, which are divided into five groups, namely: hens from the control group were fed with basic ration; chickens from the first search group were given mixed fodder of the basic ration and probiotic on the basis of association of microorganisms of genus Lactobacillus; the chickens of the second experimental group were getting the basic mixed fodder ration, probiotic and cobalt chloride was added to the mixed fodder at a dose of 0.08 mg/kg; cobalt nanoparticles (NpCo) at a dose of 0.08 mg/kg of body weight and probiotic were added into the mixed fodder to chickens from the third search group, NpCo at a dose of 0.8 mg/kg of body weight and probiotic were added into the mixed fodder to chickens from the fourth search group.

In the work it was used the prototype of cobalt nanoparticles of average size  (~100.0±10.0 nm).

Blood sampling was carried before setting the preparations (n=5), one poultry of each group, in 14, 28 days after the beginning and in 14 days after setting the drugs (n=3).

The intensity of lipid peroxidation (LPO) processes was investigated by determining the level of formation of its products in plasma – diene conjugates (DC) and malondialdehyde (MDA), the state of antioxidant system (AOS) in the body of chickens was evaluated by determining the activity of catalase and total rate of AOA of lipids.

Research has established, that continued giving of probiotics and probiotics together with the addition of cobalt nanoparticles at both doses did not cause any significant alteration in the intensity of lipid peroxidation by the level of formation of its products in the blood plasma of research chickens.

It was also established, that because of alimentary probiotic preparations entering and cobalt of various dispersed forms at a dose of 0.08 mg/kg of body weight in the blood plasma of chickens did not register any significant changes of catalase activity relative to its control level throughout the experiment.

While under the influence of probiotic compatible setting with the addition of cobalt nanoparticles in greater dose (0.80 mg/kg of body weight) there was a significant increase of catalase activity on the 14th day after the beginning of the experiment, that is an average of 24.9 % relative to its control level. Already on the 28th day after starting the drug it was observed only tends to increase the activity of this enzyme and in the future – normalization of the values of its activity to control levels.

Changes in indicator of state filling with natural pool of antioxidant resources by the level of indicator due to the total oxidative activity in the body of research chickens were more severe under the influence of drugs.

Probiotics setting together with the addition of cobalt in macro and nanodispersed forms, especially at high dose (0.8 mg/kg body weight), contributed to the maintenance of intensity of lipid per oxidation at a physiological level throughout the experiment thanks to their antioxidant resources in the organism of search poultry, which is an example of interference of adaptive-compensatory reactions.

Potential of the poultry's own resources AOC was enough under conditions of the probiotics influence together with additives of cobalt in various dispersed forms and doses to prevent excessive formation of toxic products of lipid peroxidation and corresponding inclusion of projective antioxidant mechanisms.

Key words: cobalt nanoparticles, probiotic, blood plasma, antioxidant system, chickens.