Reproductive organs are essential not only for the life of an individual but also for the survival and development of the species. The response of reproductive organs to toxic substances differs from that of other target organs, and they may serve as an ideal “barometer” for the deleterious effects of environmental pollution on animal and human health. The incidence of infertility, cancers, and associated maladies has increased in the last fifty years or more, while various anthropogenic activities have released into the environment numerous toxic substances, including cadmium, lead, and mercury. Data from epidemiological studies suggested that environmental exposure to cadmium, lead, and mercury may have produced reproductive and developmental toxicity. The present review focused on experimental studies using rats, mice, avian, and rabbits to demonstrate unambiguously effects of cadmium, lead, or mercury on the structure and function of reproductive organs. In addition, relevant human studies are discussed. The experimental studies reviewed have indicated that the testis and ovary are particularly sensitive to cadmium, lead, and mercury because these organs are distinguished by an intense cellular activity, where vital processes of spermatogenesis, oogenesis, and folliculogenesis occur. In ovaries, manifestation of toxicity induced by cadmium, lead, or mercury included decreased follicular growth, occurrence of follicular atresia, degeneration of the corpus luteum, and alterations in cycle. In testes, toxic effects following exposure to cadmium, lead, or mercury included alterations of seminiferous tubules, testicular stroma, and decrease of spermatozoa count, motility and viability, and aberrant spermatozoa morphology.

Various studies have shown that the reproductive organs are highly sensitive to toxic elements found in the environment. Due to technological progress, the use of nanoparticles has become more common nowadays. Nanoparticles are used for drug delivery because their dimensions allow them to circulate throughout the body and enter directly into the cell. Antimicrobial properties are increasingly used in the manufacture of medical devices, textiles, food packaging, cosmetics, and other consumer products. Nanoparticles provide several benefits, but aspects related to their effects on living organisms and the environment are not well known. This review summarizes current in vivo, and in vitro animal studies focused on the evaluation of toxicity of selected metal nanoparticles (Ag, ZnO, TiO₂) on male and female reproductive health. It can be concluded that higher concentrations of metal nanoparticles in the male reproductive system can cause a decrease in spermatozoa motility, viability and disruption of membrane integrity. Histopathological changes of the testicular epithelium, infiltration of inflammatory cells in the epididymis, and prostatic hyperplasia have been observed. Nanoparticles in the female reproductive system caused their accumulation in the ovaries and uterus. Metal nanoparticles most likely induce polycystic ovary syndrome and follicular atresia, inflammation, apoptosis, and necrosis also occurred.

The performance of sport horses is conditioned not only by the quality of its gene pool, but also by a large number of external factors. The most dominant being nutrition, quality of breeding, level of zootechnical care and the quality of the sports rider and coach. Important factor is the process of individuals’ adaptation to the training load occurring during the training itself. This study was focused on the analysis of salivary cortisol levels as well as hematological and biochemical blood parameters in relation to load to which the tested horses were subjected. In the study 14 horses of sport breeds were analyzed a all tested horses were in the same (medium) level of training load. Tested horses underwent following stages of workload – transportation, jumping training, parkour competition, treadmill training, riding training, shoeing and lunging of various intensity. Saliva samples were obtained using a tampon on a string which was inserted into horse's oral cavity, chewed by the horse and placed in a sterile tube with a closable lid. Afterwards, the samples were then stored in deep-freezing boxes at temperature of −80 °C. The EIA cortisol kit was used in this study. The absorbance was read at the wavelength of 450 nm against a reference wavelength of 620–630 nm or a blank sample. Blood samples were obtained at the beginning of the experiment, after half a year of running the experiment and at the end of the experiment from v. jugularis. Hematological analysis were carried out using automatic hematologic analyser and multiple parameters were observed. Analysis of biochemical parameters in blood serum were realized using commercial DiaSys kits and semiautomatic biochemical spectrophotometer. Sodium, potassium and chlorides were measured using automatic analyzer EasyLytePlus. In all monitored forms of exercise (transportation, jumping training, parkour competition, treadmill training, riding training, horse shoeing, lunging), an increase in cortisol concentrations immediately after the exercise was recorded, but only spotted statistically significant differences were found during the transportation of monitored horses. The levels of blood parameters were within the reference range during the experiment period. From a comprehensive evaluation of the results, it can be stated that there were no visible health changes to the horses that underwent the experimental load and that manipulation with horses is an important factor that has effect on horses’ stress response. In general, the results of this study show no visible impact of training and/or load on the health status of horses over entire 12-month duration of the experiment.

Feed additive consisting of polysaccharides from brown seaweeds plus phenolic acid, hydroxycinnamic acids, tannins, and flavonoids from plant extracts, was used as rabbit food supplement. Main aim of the study was to determine the effect of natural mix of marine and freshwater seaweed polyphenols on selected reproductive characteristics of male rabbits during the 90-days experiment. Natural mix was incorporated in feed-pellets for rabbits in two different concentrations – 0.3% (T1 group) and 0.6% (T2 group), compared with a control group (C group). In experimental groups a significant increase of concentration of calcium during first 30 days of supplementation was found. An increase of alanine aminotransferase, glutathione peroxidase and ferric reducing ability of plasma and a decrease in aspartate aminotransferase after 90 days were recorded in the same groups. Except for that we noticed decrease of semen distance of curved line and velocity of curved line after 30 days though only while being supplemented with 0.6% proportion of seaweed polyphenols in feed mixture. Based on the results it can be stated that the natural mix in the tested levels do not show adverse effect on male rabbit reproductive parameters, and an improvement of antioxidant status was observed. The feed additives can have a very important effect on growth, health and development of animals in general as it supplies the with the much-needed minerals, nutritional substances and antioxidants, on which we focused in our study.

Nowadays great deal of research is physiological field is conducted on experimental animals and there is a lot of criticism from the wide public on methods used. Therefore, recently there is a lot of effort focused on the welfare of the animals. Main aim of this study is to determine the effect of experimental sample collection method on the selected parameters of stress. In the experiment two sample collections of rabbit blood from marginal ear vein were realized – first using standard method with one person fixing the animal and other collecting the blood using gently fixating the animal. In the second groups experimental method of inserting the experimental animal into a sack and further collection in dark was realized. During the experiment the levels of cortisol – main stress indicator in organism and other health parameters of animals including mineral profile and haematological parameters were observed. Our results show no significant changes in levels of cortisol but also a decreasing tendency in the sample from the second (dark) collection. Haematological parameters were generally in the reference values and any significant changes except levels of lymphocytes and percent of lymphocytes which shown significant increase in the second collection period were found. Also the levels of mean corpuscular haemoglobin and percent of neutrophils unveiled a significant decrease in values. Values of mineral profile parameters have indicated no significant changes except the levels of phosphorus. Based on the result we can state that the experimental sample collection has no effect on blood parameters of the animals but we spectated a statistically insignificant decrease in the levels of cortisol which can suggest that the dark collection is possibly less stressful to the animals.

Health state of animals undergoing experimental procedures is an important topic nowadays, as even the small changes can influence the outcome of entire outcomes. Main aim of the study was to evaluate the influence of horse training on variety of blood parameters including mineral profile, energy profile, hepatic profile and haematology. In the experiment, the studied group of horses underwent training programme which consisted of transportation, lounging, riding, jumping, racing, treadmill training and shoeing. Blood samples were collected and later evaluated at the beginning, in the middle and at the end of 1-year lasting process. Our results show multiple significant changes in blood parameters, including changes to multiple minerals, such as Ca, K, Na as well as significant changes of total proteins, urea and certain hepatic profile parameters. Haematology results have also been affected in individual sample collections. Based on results of our study we can state that there have been changes to the internal milieu of the horse but also that there have not been any visible changes of the health status of the animals over the duration of the experiment.