The basis of the pathogenesis of male infertility is the processes of peroxide oxidation of biological substrates, especially lipids and proteins. By destroying the sperm membrane, toxic peroxidation products reduce its motility and ability to fertilize the egg, which is determined by a decrease in the number of motile sperm in the ejaculate. These changes lead to complete or partial male infertility. The authors of the review found that is accompanied by a damaging effect on the structural and functional activity of the gonads and is manifested, in particular, by an imbalance in the hormonal background of the male body. Similar effects are characteristic of an increase in the content of reactive Nitrogen species and its metabolites, which cause nitrosative stress, which is also the cause of male hypofertility and is inseparable from the state of oxidative stress. In scientific work it is determined that the accumulation of harmful peroxidation products leads to damage and destruction of sperm DNA, reduced activity of acrosomal enzymes and mitochondrial potential of sperm, reduced overall antioxidant activity. This makes it impossible for an adequate response of the body. Multi component antioxidant defense system resists stress. It is represented by enzymatic and non-enzymatic links, which can neutralize harmful radicals and peroxidation products. It contributes to the full manifestation of reproductive function. The presence of powerful antioxidant properties of catalase, superoxide dismutase, and enzymes of the thiol-disulfide system, which form the enzymatic system of antioxidant protection, as well as selenium, zinc, copper, other trace elements, retinol, tocopherol, ascorbic acid, and vitamins as parts of the non-enzymatic system is shown. The efficiency of registration is substantiated thin biochemical shift detectors or complex methods, such as total antioxidant status of sperm or sperm plasma, mitochondrial membrane potential, etc along with simple markers of oxidative stress, such as diene conjugates, malonic dialdehyde, and metabolites of the Nitrogen Oxide cycle. Given the leading role of oxidative stress in the development of male hypofertility, the prospect of further research is the search for modern means for correction, especially among substances with pronounced redox activity

Infertility is widespread for all species of animals and causes significant economic losses to livestock due to the loss and shortage of offspring, their reduced viability and, consequently, increased morbidity and mortality. Alimentary-deficiency factors are among the commonest causes of infertility, from which A-vitamin deficiency should be singled out. The precursor of vitamin A in the body is carotene, which is an unstable compound which is easily destroyed even under the influence of moderate factors of influence, in connection with which its deficiency is global, especially at the end of the winter – stall period of keeping animals. Accordingly it is the leading etiological factor of retinol deficiency infertility. As a result, the body has two negatives that act in parallel: carotene / vitamin A deficiency adversely affects the organs, the constituent and major functional unit of which is the secretory epithelial cell, and the free radical oxides formed in high concentration are extremely effective in destroying the cells, weakening antioxidant protection. Vitamin A has a significant effect on the reproductive function of animals both directly and indirectly. It is necessary to ensure the structure and functioning of the epithelial tissues of the organs of regulation and performance of sexual function, and therefore the physiological development of the fetus and the course of pregnancy, parturition and postpartum period, ovo- and spermiogenesis, the manifestation of sexual reflexes. Instead, its deficiency underlies the etiology and pathogenesis of retinol deficiency infertility of animals, causing changes in individual indices of homeostasis and prooxidate-antioxidant system, morphostructure of the reproductive and endocrine organs, hormonal status, sperm quality and reproductive function. The consequence is the emergence and development of gynecological, andrological, mammological and perinatal (ante-, intra-, post- and neo-) pathologies. At the same time, the addition of carotene or retinol to the diets of animals or their oral administration in cases of deficiency of vitamin A prevents impaired reproductive function. The study of the features of the etiopathogenesis of retinol deficiency infertility of animals allows programs of complex diagnostics, therapy and prevention to be developed which provide determination of carotene and vitamin A content and replenishment of the organism in cases of their deficiency.

Oxidative stress as a leading factor of male infertility requires correction with modern pharmacological agents, particularly redox-active nanoparticles, to improve sperm quality and hormonal balance. The current experimental study aimed to investigate the effect of orthovanadate nanoparticles of rare earth elements, particularly Gadolinium, with pronounced redox properties on the reproductive function of male rabbits under oxidative stress. A total of 36 mature male Hyla rabbits were divided into three groups of intact control (n = 12) and two experimental groups, including rabbits ubder oxidative stress (n = 12), induced by the introduction of tert-Butyl hydroperoxide, and those under oxidative stress plus hydrosol of gadolinium orthovanadate nanoparticles (NPs, n = 12) intake for 14 days. There were four rabbits per three replicates in each group. Animals of all groups were kept on the same diet and had free access to water. The use of NPs led to an improvement in sperm quality indicators. There was an improvement in motility and ejaculate volume indicators (by 14.6% and 39.2%, respectively), a reduction of the content of morphologically abnormal sperm by 26.7%; normalization of sex hormones, an increase in the level of total testosterone (by 113%) with a decrease in 17-β-estradiol (by 16.5%). This sex hormones improvement led to an increase in the androgen saturation of the rabbit’s body (free androgen index at the end of the experiment was 36.5%). The obtained changes were accompanied by a decrease in the oxidative load, as evidenced by a reduced content of diene conjugates and thio-barbituric acid-reactive compounds in the blood serum of rabbits by 30.4% and 26.8%, compared to the control. At the same time, there was an increase in the antioxidant potential, especially its glutathione link – the activity of glutathione peroxidase and glutathione reductase (by 42.5% and 34.2%, respectively), and the content of reduced glutathione increased by 62.3%, compared to the indicators before the introduction of NPs. The results of the study confirmed the effectiveness of using gadolinium orthovanadate NPs to correct the reproductive function of males under oxidative stress.

Studies have shown that the use of herbal feed additives «Fitopank» by Grey Ukrainian cows 30 days before calving had a positive effect not only on the body of cows-mothers and the quality of their colostrum, but also on the physiological state of the born calves and the growth energy of young animals. Adding of «Fitopank» to the cows diet helped to improve the quality of colostrum and its immunological value. It showed a probable increase of total protein by 10-14 % (P < 0.05) and immunoglobulin level by 23-25 % (P < 0.01). The titratable acidity of both the first and second milk yields was 16 % lower (P < 0.01) than in the control group. The use of this feed additive improved the immunological status of newborn calves. In their blood there was an increase of total protein content by 17 % (P < 0.05), the level of gamma globulins by 18% (p < 0.05), IgG concentrations by 14 % (p < 0.05), Ig M by 13 % and Ig A by 17 % (p<0.05), as well as the growth of T-lymphocytes by 46% and B-lymphocytes by 24 % (p < 0.01), compared with control group. Detected increased growth of the 8-12 months bulls (by 2.3%, p < 0.05) of the experimental group may indicate their tendency for better development of meat qualities. Experiment showed that the absolute live weight increase of young animals up to 18 months was higher than the control by 10.9 kg (p < 0.05). The study of the herbal supplements efficacy for the prevention and treatment of animals immunodeficiency, as well as their impact on the metabolic processes and productive qualities of farm animals will be the focus of our further research.

Different methods for oestrus induction and synchronization in domestic small ruminants have been developed.Seasonality and female's status are important factors for choosing the most appropriate treatment. In the case of females during breeding season, prostaglandins can be used since functional corpus luteum must be present in the ovaries, while during non-breeding season females should be treated with progesterone-based treatments, accompanied by equine chorionic gonadotrophin (eCG), releasing hormones and other compounds. Significant spread of oestrus synchronization during and after the breeding season has been achieved by the use of intravaginal sponges impregnated with synthetic analogues of progesterone. However, the effect of hormonal drugs on the female reproductive system may manifest differently depending on the initial functional state of reproductive organs and the hormonal status, and negative consequences can be observed when drugs are wrongly administered. In addition, insufficient knowledge about the patterns of change in the reactivity of the nervous sexual centers and the corresponding reactions of the body to the administration of hormones reduces their effectiveness, which limits the widespread use. In general, the induction and synchronization of oestrus in small ruminants is an currently important direction of scientific research and an urgent problem of sheep and goat breeding, but the proposed methods require further improvement by reducing the costand increasing biosecurity and predictability of the result.