Elevated luteinizing hormone receptor signaling or selenium treatment leads to comparable changes in adrenal cortex histology and androgen-AR/ZIP9 signaling.

The importance and regulation of adrenal androgen production and signaling are not completely understood and are scarcely studied. In addition, there is still a search for appropriate animal models and experimental systems for the investigation of adrenal physiology and disease. Therefore, the main objective of the study was to evaluate the effect of luteinizing hormone (LH) signaling and selenium (Se2+) exposure on androgen adrenal signaling via canonical androgen receptor (AR), and membrane androgen receptor acting as zinc transporter (zinc- and iron-like protein 9; ZIP9). For herein evaluations, adrenals isolated from transgenic mice with elevated LH receptor signaling (KiLHRD582G) and adrenals obtained from rabbits used for ex vivo adenal cortex culture and exposure to Se2+ were utilized. Tissues were assessed for morphological, morphometric, and Western blot analyses and testosterone and zinc level measurements.Comparison of adrenal cortex histology and morphometric analysis in KiLHRD582G mice and Se2+-treated rabbits revealed cell hypertrophy. No changes in the expression of proliferating cell nuclear antigen (PCNA) were found. In addition, AR expression was decreased (p < 0.001) in both KiLHRD582G mouse and Se2+-treated rabbit adrenal cortex while expression of ZIP9 showed diverse changes. Its expression was increased (P < 0.001) in KiLHRD582G mice and decreased (P < 0.001) in Se2+-treated rabbits but only at the dose 10 ug/100 mg/ tissue. Moreover, increased testosterone levels (P < 0.05) and zinc levels were detected in the adrenal cortex of KiLHRD582G mice whereas in rabbit adrenal cortex treated with Se2+, the effect was the opposite (P < 0.001).

The effects of age, size, and cage complexity on the behaviour of farmed female chinchillas (Chinchilla lanigera).

Even though chinchillas have been farmed for a century, there are not many studies concerning their behaviour in captivity or their optimal housing conditions, both of which are important factors in the assessment of their welfare. This study aimed to evaluate the effect of different cage types on chinchillas' behaviour and their reactions towards humans. Female chinchillas (n = 12) were kept in three types of cages: standard with a wire floor (S); standard with a deep litter floor of shavings (SR); and enlarged with a deep litter floor of shavings (LR). Animals spent 11 weeks in each type of cage. The chinchillas' reactions toward humans were observed via intruder test. Ethograms were prepared based on round-the-clock video recordings. The activity of the chinchillas was compared, taking into account the different cage types and the animals' varying responses to the hand test. The generalized ordered logistic regression model was used to ascertain whether cage type has an effect on a chinchilla's behaviour towards humans. To compare the time distribution of various activity between chinchillas, the non-parametric Scheirer-Ray-Hare test was used. Animals kept in LR cages presented significantly less timid reactions in comparison to those kept in S and SR cages. The chinchillas spent most of their time resting (68% of the day), in locomotion (23%), and eating or drinking (8%); they spent only 1% on grooming behaviour. Cage enrichment generally reduced the fear of humans. However, the average chinchilla response to the hand test was classified in each type of cage as "cautious". Analyses of the ethograms indicated that the chinchillas were active mostly during the dark stage of the day. In conclusion, the larger cage size and its enrichment (particularly litter) reduced the fearfulness and passivity of the animals, which could be evidence of better welfare conditions.

Senescent cells in rabbit, nutria and chinchilla testes-Results from histochemical and immunohistochemical studies.

Rabbit, nutria and chinchilla testes were evaluated to compare testicular cellular senescence. There were no major species-specific differences in structure of either seminiferous tubules or interstitial tissue. There, however, were occasional abnormalities in seminiferous tubule structure with there being multinucleated and exfoliated cells present in rabbit testes. Furthermore, there were seminiferous tubules without a lumen that were filled with premeiotic/meiotic cells in nutria; and tubules with vacuolization with there being no post-meiotic cells in chinchillas. There were no differences in distribution or content of acids, total proteins and polysaccharides in the testis of any of the three species. Results using comparative immunohistochemistry procedures indicated the testes contained a few senescent cells in seminiferous tubules with typical morphology and there was a large number of senescent cells in seminiferous tubules of nutrias and chinchillas that had an abnormal structure (P <0.001). Compared to rabbit testes, in which there was the least number of senescent cells in seminiferous tubules, there was a greater abundance of senescence markers in both nutria and chinchilla testes (P < 0.05; P < 0.001, respectively). Furthermore, there were small abundances of caspase 3 and LC3 in the testes of all species. In chinchilla testes, there was a lesser concentration of cholesterol (P < 0.001) and testosterone compared with the other species. Cellular senescence in testes, therefore, can be assessed by detection of morpho-functional disorders of the testis of the three species evaluated in the present study.

Evaluation of sperm morphometry of rabbits (Oryctolagus cuniculus f. domesticus).

Sperm morphology and morphometry are considered parameters in fertility diagnosis. They are especially important in the case of species for which there is no standard with respect to morphometric sperm parameters. It is then crucial to apply the staining technique that has the least influence on the sperm structure and provides the most detailed image, so as to enable measurements. The aim of the research was to assess the morphometric parameters of rabbit sperm using silver nitrate staining. The staining process revealed a detailed image of the spermatozoon head and tail, thus enabling precise measurements. From these basic morphometric parameters, four additional shape indices characterizing the sperm head were calculated: ellipticity, elongation, roughness and regularity. These parameters more precisely characterize the shape of the sperm head. Silver nitrate staining can be used as an independent technique in assessment of sperm structure or to supplement routine diagnostics.

Determination of cytogenetic markers for biological monitoring in coypu (Myocastor coypu).

Cytogenetic tests are used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping predict possible genetic consequences in animal cells and assess animal resistance. The aim of this study was to examine, using cytogenetic tests, the spontaneous chromosome and DNA damage in coypu lymphocytes. Four tests: fragile site (FS), bleomycin (BLM), micronucleus, (MN) and comet were used for the first time in coypu cells. The averages with standard deviations obtained in the research were as follows: 3.30 ± 0.80 fragile sites/cell; 0.63 ± 0.80 BLM damage/cell; 6.10 ± 0.53% binucleated cells with MN; and 3.24 ± 0.63% DNA in tail. The present analysis showed high interindividual variation in spontaneous chromosomal and DNA damage levels. In the case of micronucleus, fragile sites, and comet assays, the differences between animals were statistically significant. The data suggest that these assays are sensitive enough to detect some effects on an individual animal and can be proposed as tools for coypu biomonitoring.

Comparison of the structure of chinchilla sperm isolated from semen and from the tail of the epididymis.

Sperm cells isolated from the tail of the epididymis and from the semen of the same individuals were analysed. The use of silver nitrate to stain sperm cells isolated from the tail of the epididymis made it possible to identify structures that were not visible in the sperm from semen. Silver nitrate very clearly distinguished the acrosomal and distal parts of the sperm head. Following silver nitrate staining, the sperm isolated from the tail of the epididymis were characterized by dark 'collars' in the distal part of the head. These 'collars' are not visible in the sperm cells isolated from semen. The results of the study indicate differences in the dimensions of sperm isolated from the tail of the epididymis and sperm in semen. Sperm isolated from the tail of the epididymis had smaller heads, despite their longer length, and had longer midpieces and tails than ejaculate sperm. Silver nitrate staining is a simple and fast technique. Silver nitrate makes it possible to identify the acrosome and post-acrosomal region of the sperm head and to clearly identify the midpiece. Therefore, it can be successfully used to supplement routine techniques for evaluating sperm morphology or as an independent technique.

Infrared Thermography as an Indicator of Heat Loss in Fur-Chewing Chinchillas (Chinchilla Lanigera).

Fur-chewing is a common problem in chinchilla (Chinchilla lanigera). It may affect the welfare of animals due to heat loss, thereby possibly impacting food and water intake to maintain body temperature. In this context, infrared thermography seems to be a suitable method of measuring heat emissions from the surface of objects. Sexually mature male domestic chinchillas were divided into two groups: "non-fur chewers", exhibiting normal behaviour (n = 25), and "fur chewers" displaying fur-chewing behaviour (n = 23). Food and water intake (mean ± SD) measured in the control animals amounted to 20.7 ± 4.52 g and 15.9 ± 3.45 mL, while in fur-chewing chinchillas were 25% and 33% higher, respectively. Metabolic energy intake, were calculated 2.2 and 2.8 W for the control and fur-chewing animals, respectively. Heat flux through chewed areas was 6.06 mW cm-2, which is 2.8 times higher than through undamaged chinchilla fur. To sum up, thermal imagingexplicitly shows that fur-chewing causes increased heat loss. Disturbances in the maintenance of thermal homeostasis may be an additional factor that reduces the welfare of these animals.

The Effect of Bromodeoxyuridine on Spontaneous Sister Chromatid Exchange Frequency in Rabbit (Oryctolagus cuniculus) and Coypu (Myocastor coypu) Chromosomes.

The sister chromatid exchange test is regarded as a highly sensitive cytogenetic assay. It measures chromosome sensitivity to particular damage factors and provides information on control and repair mechanism performance. It is instrumental in the early identification of the effects of noxious factors present in the habitat. This investigation was aimed at identifying sister chromatid exchange sites in coypu and rabbit chromosomes, as well as determining the spontaneity of the process by applying different BrdU doses. The chromosomes were obtained from an in vitro culture of blood lymphocytes, supplemented with 4 different BrdU doses: 0.25/0.5/1.0/2.5 µg/ml in order to identify spontaneous sister chromatid exchanges in both animal species. The chromosomes were stained according to the FPG method. Spontaneous SCEs were observed in coypu at a concentration of 1.0 µg/ml, and in rabbits at 0.5 µg/ml. The mean SCE/cell incidence was 1.41±1.15 in coypu, and 2.69±2.14 in rabbits. Differences in SCE incidence were identified between the analysed animal species and the applied BrdU doses.

Biochemical adaptations to dive-derived hypoxia/reoxygenation in semiaquatic rodents.

To meet the challenges presented by dive-derived hypoxia/reoxygenation transition, the aquatic mammals possess multi-level adaptations. However, the adjustments of the semiaquatic animals as modern analogs of evolutionary intermediates between ancestral terrestrial mammals and their fully aquatic descendants are still not fully elucidated. The aim of this study was to analyze the total lactate dehydrogenase (LDH) activity (in the lactate to pyruvate direction), the LDH patterns and the antioxidant defense in the tissues (heart, kidney, liver, lung, muscle, spleen) of semiaquatic rodents such as Eurasian beaver (Castor fiber), muskrat (Ondatra zibethicus) and nutria (Myocastor coypus). Samples from Wistar rat were used for comparison. Semiaquatic rodents had higher catalase activity compared to rats. The superoxide dismutase activity was higher and the catalase activity was lower in almost all tissues of muskrat than of both beaver and nutria. Comparing beaver and nutria, no significant differences in the antioxidant enzyme activities were found for the heart, kidney and liver. In beaver, most of the examined tissues (heart, kidney, lung and spleen) use lactate as preference to glucose as a substrate but in muskrat the heart, liver and skeletal muscle showed the increased LDH activity. Nutria had the unusual LDH properties that are needed to be further investigated. Our results suggest that beaver, nutria and muskrat have distinct mechanisms of adaptation to diving hypoxia/reoxygenation and support the hypothesis that semiaquatic mammals are the intermediate animals that help to define which potential selection factors and mechanical constraints may have directed the evolution of the aquatic forms.

The Alice - "Follow the White Rabbit" - parasites of farm rabbits based on coproscopy.

The aim of the study, conducted in the years 2011-2013, was to determine the level of gastrointestinal parasites infection in New Zealand White rabbits, kept at the Experimental Station of the University of Agriculture in Krakow. The study showed rabbits protozoan infection with the genus Eimeria, belonging - based on the sporulation method - to the following species: E. magna, E. media, E. perforans, E. stiedae and E. irresidua. The highest prevalence of infection, as well as the intensity of oocysts output (OPG - oocysts per gram of faeces), was noted for E. magna and E. media - respectively 31.4 % (19477.3 OPG), and 40.0 % (14256.07 OPG). The infection of rabbits with Eimeria spp. differed significantly between years. With regard to oocysts output, the level of infection was strongly connected with the age of rabbits, being higher in young animals. However, the range of infection was highest among adults. Among nematodes, Passalurus ambiguus pinworm was regularly found (prevalence reached 21.9%), other species - Trichuris leporis, and Graphidium strigosum were rarely noted. The overall infection with nematodes did not differ between years. Similarly, as in the case of Eimeria older individuals were more often infected by nematodes. We observed some trends in parasite oocysts/eggs output; the protozoan oocysts were recorded more often in faecal samples collected in the evenings, whereas the nematodes eggs occurred frequently in the mornings. This situation may be related to the phenomenon of coprophagy occurring in the mammals of Lagomorpha order. The results of the study indicate that especially coccidiosis constitute permanently throughout the years an important problem in the rabbitry examined.

Influence of Selected Extenders for Liquid Storage at 4 degrees C of Breeding Chinchilla (Chinchilla lanigera) Semen on Sperm DNA Integrity.

The influence of two commercial and two laboratory oriented extenders on survival rate and DNA integrity of chinchilla (Chinchilla lanigera) sperm was determined during liquid storage. Semen was collected using an electroejaculator from 6 adult male chinchillas. Ejaculates (n = 16) were diluted with extenders to obtain a concentration of 40 x 10 (3) sperm/5 µl. After dilution the semen samples were stored at 4"C. The percent motility, progressive motility, and morphology were assessed conventionally, whereas DNA integrity was evaluated by Single Cell Gel Electrophoresis (comet) assay at 0 (just after dilution), 24, 48 and 72 h. Conventional assessment of sperm quality showed that commercial extenders are characterized by the lowest sperm survival parameters out of the investigated extenders. In commercial extenders spermatozoa lost their capacity for progressive motility compared to laboratory extenders. After 24 h storage, from 21.67% to 30% of motile sperms were observed in commercial extender whereas total sperm motility was 63.33% (41.67% with progressive motility) in samples in which stallion semen extender was used. After 72 h storage, 10% of sperm were motile in stallion semen extender while no sperm movement was observed in tubes containing the commercial extender. Furthermore, a lower percentage of damaged spermatozoa in laboratory oriented extenders was demonstrated. It was also stated that along with the extended time of semen storage at 4 degrees C, commercial extenders lost their protective action. An analysis of DNA content in the heads of sperm cells and tail moment (TM) showed that the most useful extender for liquid preservation of chinchilla semen was the extender for stallions.