The purpose of the research was to study the effect of gestational age on the state of the enzymatic link of antioxidant protection (AOP) of lipid peroxidation products (LPO) in cows with anemia syndrome and chronic systemic inflammation. Three (3) groups of cows were formed: group I (n=15) – healthy; group II (n=8) – with hypochromic microcytic anemia; group III (n=7) – with chronic systemic inflammation syndrome of low intensity. On days 150-160, 210-220 and 260-265 of gestation, blood samples were taken to study the indicators of LPO, AOP and endogenous intoxication. There were obtained the data on the peculiarities of the state of the LPO-AOP system in cows with various clinical states during gestation. It has been established that there is an inverse correlation between the period of gestation and catalase activity. A significant direct correlation of high strength with respect to the level of nitric oxide has also been revealed. In cows with anemia, less intense tendencies for an increase in nitric oxide have been noted, which may have an important role in the control of fetoplacental hemodynamics and saturation of the fetal blood with oxygen. In group I and II, the level of diene conjugates had a significant direct correlation of noticeable strength, but in group III, the binding strength increased and became high, which was reflected at the level of molecules of average molecular weight, detectable at a wavelength of 254 nm. Thus, with an increase in the duration of gestation, there is an increase in the LPO intensity, which is most pronounced in cows with a syndrome of chronic systemic inflammation of a low degree of intensity, as a result of which endogenous intoxication develops. At the same time, nitric oxide is less actively produced in cows with anemia that can lead to the development of fetoplacental insufficiency and hypoxic state of the fetus.

The objective of our research was to study the features of the colostral immunity formation in the newborns obtained from the cows with different clinical conditions during gestation. The object of the study was Red-Motley cows (n=28) in the third trimester of gestation and the newborn calves obtained from them. Group I – clinically healthy (control, n=8), group II – animals with hepatodystrophy (n=6), group III – animals with a combined course of hepatodystrophy and anemia (n=14). It has been found that in the cows with liver pathology and/or anemia, the colostrum of the first milk yield contains less protein and immunoglobulins by 24.1-25.4% and 11.9-14.2% (P ˂ 0.05), respectively. However, it was noted that in the calves obtained from the cows of group II, the blood serum content of total immunoglobulins after colostrum feeding did not differ from the values of the control group, while in the calves obtained from the cows of group III, the same indicator was lower by 43.0% (P ˂ 0.05). To clarify the reasons for this phenomenon, the Spearman correlation analysis was carried out, which showed that the level of total immunoglobulins in colostrum did not have a significant effect on their amount in the blood serum of calves after colostrum feeding (Rs = 0.40, P ˃ 0.05). In this case, the presence of anemia in calves was of decisive importance (Rs = 0.77, P ˂ 0.05). Thus, the formation of colostral immunity in calves depends not only on the quality of colostrum, but also on the clinical status of the newborn and in particular the presence of a hypoxic and acedotic condition.

The review article analyzes the existing world experience in the use of interferons IFN-α and -γ as well as drugs based on them in clinical veterinary practice in cattle and pigs. The selection of literary sources was carried out on the basis of their relevance and the depth of the research (search retrospectiveness is 30 years). It has been established that IFNs are widely used in the prevention and treatment of both infectious and non-infectious diseases, which can be divided into 3 groups: viral infections, oncological diseases, bacterial and aseptic diseases. The use of IFNs is due to their antiviral activity and immunoregulatory effect. Thus, IFN-α exhibits antiviral activity and is the first line of nonspecific immune defense, an inducer of IFN-γ synthesis and the main coordinator of the body's successful response to a viral infection. At the same time, IFN-γ provides immunoregulatory, anti-inflammatory and mediated antibacterial action by stimulating the production of macrophages and participating in the differentiation of lymphocytes. Clinical efficacy is expressed in a decrease or cessation of the infectious process, a decrease in leukocytosis and neutrophilia, relief of acidotic syndrome, an increase in the body weight of animals and an improvement in the general clinical condition. Currently, IFN therapy is one of the most promising and constantly expanding areas of immunopharmacology and treatment of common respiratory, gastrointestinal, obstetric-gynecological diseases in farm animals.

The article provides an overview of the most significant works of domestic and foreign authors devoted to the Ehrlich ascites carcinoma biological model. The analysis of the available literary sources showed that despite the long history of the existence of this model and its application in biomedical research, it has not yet become widespread in veterinary medicine. It should be noted that the Ehrlich ascites carcinoma model has a number of peculiarities that allow it to be used for the needs of veterinary medicine, in particular, experimental pharmacology at the stage of drug design and its preclinical testing. The high resistance of malignant cells and tumor survival in experimental animals, as well as the ease of its cultivation and relatively rapid tumor growth, make this model a convenient biological object for research. The effect of tumor cells on the body of the animal with a tumor leads to a change in a number of biochemical indicators of various tissues and organs, and a general toxic effect. In this case, an imbalance of the free-radical and antioxidant systems is observed, the body is exposed to oxidative stress. The immune system under the effect of Ehrlich ascites carcinoma also undergoes a number of changes. Thus, in response to the development of tumor-induced pathological processes, recruitment of immunocompetent cells and an antitumor immune response are observed, which at the same time is suppressed as carcinoma cells grow under the action of immunosuppressive physiologically active compounds produced by the tumor, escape of tumor cells from immunological surveillance and remodelling of immune cells in the tumor microenvironment. These processes lead to suppression of the immune system and as a result to the death of animals. These peculiarities make it possible to use the Ehrlich transplantable ascites carcinoma model for testing new veterinary drugs with potential antiblastoma, immunomodulatory, antitoxic properties, as well as medicinal formulations for restoring biochemical indicators and redox homeostasis under conditions of tumor-induced immunosuppression and chronic inflammatory process, and also to study the mechanisms of cell adaptation, including the immune system, under the action of carcinogenesis factors.