Social and locomotor play behavior of dairy calves kept with the dam either full time or half time in straw-bedded pens.

This study investigated play behavior of dairy calves kept with the cow either full time or half time in groups of 4 dam-calf pairs in 68-m2 straw-bedded pens. Twenty-four of 48 calves entering the experiment (2 calves in each of 12 pens) were observed during 24 h at 3 and 7 wk of age. The total duration of locomotor play did not differ between the 2 treatments, but full-time calves performed less frontal pushing (social play). Irrespective of treatment, calves performed less parallel locomotor play and more frontal pushing at 7 wk than 3 wk of age. Analyzing the intensity of play behavior during milking times (morning and afternoon, respectively), during the night and between morning and afternoon milking, showed that calves performed locomotor play more intensively after the cows had left the pen for milking than during other periods. The results illustrate the importance of space and external stimulation for the performance of play behavior.

Retrospective review of 27 European cases of fatal elephant endotheliotropic herpesvirus-haemorrhagic disease reveals evidence of disseminated intravascular coagulation.

Elephant endotheliotropic herpesvirus haemorrhagic disease (EEHV-HD) is widely acknowledged as the most common cause of mortality in young Asian elephants (Elephas maximus) in captivity. The objective of the current study was to perform a blinded, retrospective pathology review of European EEHV-HD fatalities, constituting the largest systematic assessment of EEHV-HD pathology to date. Findings between viral genotypes were compared with the aim to investigate if disseminated intravascular coagulation (DIC) could be substantiated as a significant complicating factor, thereby increasing the understanding of disease pathophysiology. Immunohistochemical staining confirmed endothelial cell (EC) damage and the presence of EC intranuclear inclusion bodies, demonstrating a direct viral cytopathic effect. Microthrombi were observed in 63% of cases in several organs, including lungs, which, together with widespread haemorrhage and thrombocytopenia reported in EEHV-HD case reports, supports the presence of overt DIC as a serious haemostatic complication of active EEHV infection. Death was attributed to widespread vascular damage with multi-organ dysfunction, including severe acute myocardial haemorrhage and subsequent cardiac failure. Systemic inflammation observed in the absence of bacterial infection may be caused by cytokine release syndrome. Findings reinforce the necessity to investigate cytokine responses and haemostatic status during symptomatic and asymptomatic EEHV viraemia, to potentially support the use of anti-inflammatory treatment in conjunction with anti-viral therapy and cardiovascular support.

Signalling of multiple interleukin (IL)-17 family cytokines via IL-17 receptor A drives psoriasis-related inflammatory pathways.

BACKGROUND: The interleukin (IL)-23/IL-17 immune axis is of central importance in psoriasis. However, the impact of IL-17 family cytokines other than IL-17A in psoriasis has not been fully established. OBJECTIVES: To elucidate the contribution of IL-17 family cytokines in psoriasis. METHODS: To address the expression and localization of IL-17 family cytokines, lesional and nonlesional skin samples from patients with psoriasis were analysed by several complementary methods, including quantitative polymerase chain reaction, immunoassays, in situ hybridization and immunohistochemistry. Mechanistic studies assessing the functional activity of IL-17 family cytokines were performed using ex vivo cultured human skin biopsies and primary human keratinocytes. RESULTS: We demonstrated that IL-17A, IL-17F, IL-17A/F and IL-17C are expressed at increased levels in psoriasis lesional skin and induce overlapping gene expression responses in ex vivo cultured human skin that correlate with the transcriptomic signature of psoriasis skin. Furthermore, we showed that brodalumab, in contrast to ixekizumab, normalizes gene expression responses induced by the combination of IL-17A, IL-17F, IL-17A/F and IL-17C in human keratinocytes. CONCLUSIONS: Several IL-17 ligands signalling through IL-17RA are overexpressed in psoriasis skin and induce similar psoriasis-related inflammatory pathways demonstrating their relevance in relation to therapeutic intervention in psoriasis.

Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors.

We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La_{2}CuO_{4+y}. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La_{2-x}Sr_{x}CuO_{4} (x=0.07) and La_{2-x}Ba_{x}CuO_{4} (x=0.095).

Review: Factors affecting fouling in conventional pens for slaughter pigs.

This review assesses factors affecting fouling in conventional pens for slaughter pigs. Fouling of the pen happens when pigs change their excretory behaviour from occurring in the designated dunging area to the lying area. This can result in a lower hygiene, bad air quality, extra work for the farmer, disturbance of the pigs' resting behaviour and an increase in agonistic interactions. A systematic search was conducted and results narrowed down to 21 articles. Four factors were found to affect fouling directly: insufficient space allowance, the flooring design of the pen, the thermal climate and pigs' earlier experience. Further, these primary factors are affected by secondary factors such as the shape of the pen, the weight of the pigs and especially the heat balance of the pigs, which is affected by several tertiary factors including, for example, temperature, humidity and draught. Results indicate that the most important factor to control when trying to prevent fouling of a pen is the pen climate. An appropriate climate may be accomplished through floor cooling in the designated lying area, sprinklers above the designated dunging area and by ensuring a more optimal ambient temperature curve that also fits the weight of the pigs in different stages of the production. All in all, fouling of the pen in conventional slaughter pigs is a multifactorial problem, but it is important to focus on increasing the comfortability, and especially the climate, of the designated lying area.

Living on the edge: Daily, seasonal and annual body temperature patterns of Arabian oryx in Saudi Arabia.

Heterothermy, the ability to allow body temperature (Tb) to fluctuate, has been proposed as an adaptive mechanism that enables large ungulates to cope with the high environmental temperatures and lack of free water experienced in arid environments. By storing heat during the daytime and dissipating it during the night, arid-adapted ungulates may reduce evaporative water loss and conserve water. Adaptive heterothermy in large ungulates should be particularly pronounced in hot environments with severely limited access to free water. In the current study we investigated the effects of environmental temperature (ambient, Ta and soil, Ts) and water stress on the Tb of wild, free-ranging Arabian oryx (Oryx leucoryx) in two different sites in Saudi Arabia, Mahazat as-Sayd (MS) and Uruq Bani Ma'arid (UBM). Using implanted data loggers wet took continuous Tb readings every 10 minutes for an entire calendar year and determined the Tb amplitude as well as the heterothermy index (HI). Both differed significantly between sites but contrary to our expectations they were greater in MS despite its lower environmental temperatures and higher rainfall. This may be partially attributable to a higher activity in an unfamiliar environment for translocated animals in UBM. As expected Tb amplitude and HI were greatest during summer. Only minor sex differences were apparent that may be attributable to sex-specific investment into reproduction (e.g. male-male competition) during rut. Our results suggest that the degree of heterothermy is not only driven by extrinsic factors (e.g. environmental temperatures and water availability), but may also be affected by intrinsic factors (e.g. sex and/or behaviour).

A framework for the etiology of running-related injuries.

The etiology of running-related injury is important to consider as the effectiveness of a given running-related injury prevention intervention is dependent on whether etiologic factors are readily modifiable and consistent with a biologically plausible causal mechanism. Therefore, the purpose of the present article was to present an evidence-informed conceptual framework outlining the multifactorial nature of running-related injury etiology. In the framework, four mutually exclusive parts are presented: (a) Structure-specific capacity when entering a running session; (b) structure-specific cumulative load per running session; (c) reduction in the structure-specific capacity during a running session; and (d) exceeding the structure-specific capacity. The framework can then be used to inform the design of future running-related injury prevention studies, including the formation of research questions and hypotheses, as well as the monitoring of participation-related and non-participation-related exposures. In addition, future research applications should focus on addressing how changes in one or more exposures influence the risk of running-related injury. This necessitates the investigation of how different factors affect the structure-specific load and/or the load capacity, and the dose-response relationship between running participation and injury risk. Ultimately, this direction allows researchers to move beyond traditional risk factor identification to produce research findings that are not only reliably reported in terms of the observed cause-effect association, but also translatable in practice.

Prevalence of Taxa of Pasteurellaceae Among Populations of Healthy Captive Psittacine Birds.

Sixty-two strains of Pasteurellaceae-like bacteria were isolated from the tracheas of 87 clinically healthy psittacine birds in two Danish zoos. The isolates were identified by a combination of rpoB and 16S rRNA gene sequencing and by matrix-assisted laser desorption-ionization time of flight. Twenty-eight strains belonged to the genus Volucribacter or were related to this genus and to the unnamed taxon 34 of Bisgaard, and 28 strains were related to the unnamed taxon 44 of Bisgaard. Four strains were identified as Pasteurella multocida , two isolates were classified with the related taxon 45 of Bisgaard, and a single isolate was classified as Pasteurella sp. The investigation documented an unrecognized reservoir of rarely reported and unclassified or unnamed species of Pasteurellaceae-like bacteria in psittacine birds. The results were in accordance with a recent report on isolation of Pasteurellaceae from diseased psittacine birds, and the investigation documented that the same taxa of Pasteurellaceae-like bacteria can be isolated from apparently healthy birds as well as from diseased birds.

Quantitative Macroscopic Anatomy of the Giraffe (Giraffa camelopardalis) Digestive Tract.

Quantitative data on digestive anatomy of the world's largest ruminant, the giraffe, are scarce. Data were collected from a total of 25 wild-caught and 13 zoo-housed giraffes. Anatomical measures were quantified by dimension, area or weight and analysed by allometric regression. The majority of measures scaled positively and isometrically to body mass. Giraffes had lower tissue weight of all stomach compartments and longer large intestinal length than cattle. When compared to other ruminants, the giraffe digestive tract showed many of the convergent morphological adaptations attributed to browsing ruminants, for example lower reticular crests, thinner ruminal pillars and smaller surface area of the omasal laminae. Salivary gland weight of the giraffe, however, resembled that of grazing ruminants. This matches a previous finding of similarly small salivary glands in the other extant giraffid, the okapi (Okapia johnstoni), suggesting that not all convergent characteristics need be expressed in all species and that morphological variation between species is a combination of phylogenetic and adaptational signals.

Risk of depressive disorder following disasters and military deployment: systematic review with meta-analysis.

BACKGROUND: Numerous studies describe the occurrence of post-traumatic stress disorder following disasters, but less is known about the risk of major depression. AIMS: To review the risk of depressive disorder in people surviving disasters and in soldiers returning from military deployment. METHOD: A systematic literature search combined with reference screening identified 23 controlled epidemiological studies. We used random effects models to compute pooled odds ratios (ORs). RESULTS: The average OR was significantly elevated following all types of exposures: natural disaster OR = 2.28 (95% CI 1.30-3.98), technological disaster OR = 1.44 (95% CI 1.21-1.70), terrorist acts OR = 1.80 (95% CI 1.38-2.34) and military combat OR = 1.60 (95% CI 1.09-2.35). In a subset of ten high-quality studies OR was 1.41 (95% CI 1.06-1.87). CONCLUSIONS: Disasters and combat experience substantially increase the risk of depression. Whether psychological trauma per se or bereavement is on the causal path is unresolved.

Pasteurellaceae bacteria from the oral cavity of Tasmanian devils (Sarcophilus Harrisii) show high minimum inhibitory concentration values towards aminoglycosides and clindamycin.

UNLABELLED: Threatened by Devil Facial Tumor Disease, the Tasmanian devil populations are vulnerable and decreasing. Additionally, the devils' biting behaviour elevates their risk of acquiring bite wound infections caused by members of the bacterial Pasteurellaceae family that are natural inhabitants of the oral microbiota. In medical management of such bite wounds, antimicrobial susceptibility profiles are crucial. Prior to this investigation, no available data on minimal inhibitory concentration (MIC) values existed. A total of 26 isolates obtained from the oral cavity of 26 healthy Tasmanian devils were tested for their antimicrobial susceptibility by broth micro dilution. Most prominently, high MIC values for clindamycin (≥4 µg ml(-1) ), gentamicin (≥8 µg ml(-1) ) and amikacin (≥32 µg ml(-1) ), were observed for 92, 77 and 73% of the strains tested respectively. This study may be used as a guideline for antimicrobial therapy against bite wound infections caused by Pasteurellaceae originating from the oral cavity of Tasmanian devils. SIGNIFICANCE AND IMPACT OF THE STUDY: Tasmanian devils' aggressive behaviour makes bite wounds in fellow devils and human caretakers a common entity. Pasteurellaceae bacteria are common inhabitants of the oral microbiota of Tasmanian devils and a likely cause of bite wound infections. Here, for the first time, we report antimicrobial sensitivity profiles from a broad collection of Pasteurellaceae isolates obtained from the oral cavity of Tasmanian devils. Low MIC values were observed for the majority of the 22 antimicrobial agents included, yet nearly all strains were tolerant to clindamycin and the aminoglycosides. The work can serve as a guide for clinicians involved in treatment of bite wounds inflicted by devils in animals and humans.

A genome survey sequencing of the Java mouse deer (Tragulus javanicus) adds new aspects to the evolution of lineage specific retrotransposons in Ruminantia (Cetartiodactyla).

Ruminantia, the ruminating, hoofed mammals (cow, deer, giraffe and allies) are an unranked artiodactylan clade. Around 50-60 million years ago the BovB retrotransposon entered the ancestral ruminantian genome through horizontal gene transfer. A survey genome screen using 454-pyrosequencing of the Java mouse deer (Tragulus javanicus) and the lesser kudu (Tragelaphus imberbis) was done to investigate and to compare the landscape of transposable elements within Ruminantia. The family Tragulidae (mouse deer) is the only representative of Tragulina and phylogenetically important, because it represents the earliest divergence in Ruminantia. The data analyses show that, relative to other ruminantian species, the lesser kudu genome has seen an expansion of BovB Long INterspersed Elements (LINEs) and BovB related Short INterspersed Elements (SINEs) like BOVA2. In comparison the genome of Java mouse deer has fewer BovB elements than other ruminants, especially Bovinae, and has in addition a novel CHR-3 SINE most likely propagated by LINE-1. By contrast the other ruminants have low amounts of CHR SINEs but high numbers of actively propagating BovB-derived and BovB-propagated SINEs. The survey sequencing data suggest that the transposable element landscape in mouse deer (Tragulina) is unique among Ruminantia, suggesting a lineage specific evolutionary trajectory that does not involve BovB mediated retrotransposition. This shows that the genomic landscape of mobile genetic elements can rapidly change in any lineage.

Ophidian Spectaculitis and Spectacular Dysecdysis: A Histologic Description.

The histologic features of abnormal spectacles in 60 snakes from the 5 families of Boidae, Colubridae, Elapidae, Pythonidae, and Viperidae are described in a retrospective study conducted on specimens submitted to a private diagnostic service during a period of 15 years. Fifty-two snakes had inflammatory reactions in the spectacle. The stroma and outer epithelium of the spectacle were the layers most often involved in inflammatory disease. Lesions of the outer epithelium included edema, hyperkeratosis, and granulocyte infiltration occasionally with bacterial colonies and fungal elements. The stroma had infectious agents and inflammatory reactions in vessels and between the collagen fibrils. The inner epithelium had varying degrees of hyperplasia and hypertrophy, but no infectious agents were seen. Infectious agents in these cases included mites, bacterial disease, fungal disease, or a combination of bacterial and fungal disease. Special stains identified the bacteria most commonly involved to be Gram-positive cocci. Thirteen snakes had dysecdysis of the spectacle. Of these, 5 displayed a concurrent inflammatory reaction of the spectacle, while the remaining 8 snakes had extra keratin layers on a spectacle with an otherwise normal appearance. These keratin layers were attached to serocellular crusts located on the inner surface of the periocular scales. The cause for dyskeratotic lesions of the spectacle was not always apparent, and concurrent acariasis, other forms of dermatitis, trauma, suboptimal husbandry, and visceral disease were considered possible contributing factors. It was notable that only 4% of the submitted cases were found to have spectaculitis and/or spectacular dysecdysis.

The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate.

BACKGROUND: The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS: Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined. RESULTS: GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively. CONCLUSION: In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP.

Gender differences in first-episode psychosis at 5-year follow-up--two different courses of disease? Results from the OPUS study at 5-year follow-up.

OBJECTIVE: Gender differences in psychosis have been investigated, and the results have contributed to a better understanding of the disease, but many questions are unanswered. In clinical terms, women and men with psychosis differ in terms of access to social support, tendency of substance abuse, level of functioning and symptom patterns. We aimed to investigate how gender differences at onset of psychosis develop during the first 5years of treatment. METHOD: A total of 578 patients with a first-episode psychosis in the schizophrenia spectrum were included in the Danish OPUS trial--a randomized clinical trial comparing 2 years of intensive early-intervention programme with standard treatment. All patients were assessed with validated instruments at inclusion, and after 2 and 5 years. Data were analysed for significant gender differences. RESULTS: Males have significantly higher levels of negative symptoms at all times, and are more likely to live alone and suffer from substance abuse. Females reach higher levels of social functioning at follow-up, and show a greater tendency to be employed or in education than males. Markedly more women than men live with children. More women than men reach a state of recovery and are more compliant with medication. CONCLUSION: There are significant gender differences at 2- and 5-year follow-up in this large cohort of first-episode psychotic patients. Males and females show different symptomatology and different levels of social functioning.

Change in cannabis use, clinical symptoms and social functioning among patients with first-episode psychosis: a 5-year follow-up study of patients in the OPUS trial.

BACKGROUND: Several studies indicate that cannabis use among patients with psychotic disorders is associated with worse outcome, but only a few studies have controlled for baseline condition and medication. METHOD: At 5-year follow-up, interviews were carried out with 314 first-episode psychosis patients included in the OPUS trial. The patients included were in the age range of 18 to 45 years old and 59% were male. Cannabis use was extracted from the Schedule for Clinical Assessment in Neuropsychiatry. At follow-up, the patients were divided into different groups according to the variable cannabis use: abstainers, stoppers, starters and continuers. Psychotic, negative and disorganized dimensions (ranging from zero to five) were calculated for each of the four groups based on the Schedule for the Assessment of Positive and Negative Symptoms in Schizophrenia. RESULTS: Cannabis users were younger (24.6 years v. 27.4 years, p < 0.001) and had a lower level of education. At the 5-year follow-up, users of cannabis had higher scores on the psychotic dimension [difference 0.97, 95% confidence interval (CI) 0.41-1.53, p = 0.001] and lower levels of the Global Assessment of Functioning (difference 8.26, 95% CI 2.13-14.39, p = 0.01). Those who stopped using cannabis between entry and 5-year follow-up had a significantly lower level of psychotic symptoms at 5-year follow-up even after controlling for baseline level of psychotic symptoms and for insufficient antipsychotic medication (adjusted difference in psychotic dimension -1.04, 95% CI -1.77 to -0.31, p = 0.006). CONCLUSIONS: Continuous cannabis use was associated with higher levels of psychotic symptoms after 5 years, and this association was only partly explained by insufficient antipsychotic medication.

Salmonella prevalence among reptiles in a zoo education setting.

Clinically healthy reptiles may shed Salmonella and therefore act as a potential zoonotic threat. Most people in Northern European countries are rarely exposed to reptiles, but many zoos have education departments where children have direct contact with this group of animals. The objectives of this study were to determine the prevalence and serotype distribution of Salmonella among reptiles in the Education Department (n = 55) at Copenhagen Zoo and compare it to the Zoo's main reptile collection (n = 145) to evaluate the zoonotic risk. Salmonella was isolated from cloacal swabs by selective enrichment, and a single isolate from each positive sample was further identified by biochemical tests and serotyped. The overall prevalence was 35% (69/200) with significant difference between the Education Department (64%, 35/55) and the main reptile collection (23%, 34/145). A total of 28 serotypes were detected. Ten serotypes were isolated from more than one specimen and four from more than one species. Salmonella enterica subsp. enterica serovar Eastbourne was the predominant serotype (32%, 22/69) and was also the serotype isolated from most reptile species (n = 7). Transmission of serotypes from one department to another was very limited indicated by the serotype distribution. Despite the relative high prevalence observed among the reptiles in the Zoo's Education Department compared to the reptiles in the Zoo's main reptile collection, no Salmonella cases have been linked to the Zoo, and Salmonella ser. Eastbourne is very rarely isolated from humans in Denmark. Simple hygienic procedures such as hand washing which is consistently carried out following handling of reptiles at the Education Department may reduce the risk and therefore contribute to this low prevalence.

Activity of ancient RTE retroposons during the evolution of cows, spiral-horned antelopes, and Nilgais (Bovinae).

In the genome of Artiodactyla (cow, sheep, pigs, camels, and whales), a major retroposon group originated from a presumable horizontal transfer of BovB, a retrotransposon-like element retroposon, between 52 and 70 million years ago. Since then, BovB retroposons have proliferated and today occupy a quarter of the cow's genome sequence. The BovB-related short interspersed elements (SINEs) were used for resolving the phylogeny of Bovinae (cows, spiral-horned antelopes, and nilgais) and their relatives. In silico screening of 55,000 intronic retroposon insertions in the cow genome and experimental validation of 126 introns resulted in 29 informative retroposon markers for resolving bovine evolutionary relationships. A transposition-in-transposition analysis identifies three different phases of SINE activity and show how BovB elements have expanded in the cattle genome.

Methane production by red-necked wallabies (Macropus rufogriseus).

The claimed low production of CH(4) by kangaroos and marsupials in general has been questioned because of a lack of data. The extent of their CH(4) production is of interest both from the point of view of discussing meat production of marsupials and as a basis for developing methods to reduce CH(4) production from ruminants. In the present experiment, the CH(4) production of 8 red-necked wallabies (Macropus rufogriseus) was measured of which 4 were fed 2 different diets in an open-circuit respiration chamber. These results were compared with a newly developed, inexpensive, and simple method that does not influence the behavior of the animal, and where the ratio between CH(4) and CO(2) is measured and used together with the calculated CO(2) to quantify the CH(4) production. The experiment demonstrated that the wallabies produce CH(4). However, the amount of CH(4) produced by these wallabies was between 1.6 and 2.5 L/d equivalent to 1.6 and 2.5% of GE or 2.2% and 3.5% of DE intake and 0.22 L/BW, kg(0.75). This is between 25 and 33% of what can be expected from ruminants fed the same diet. Based on the uneven release of CH(4) with time, it is most likely that the CH(4) is excreted through flatulence and not through breathing as is seen in ruminants. The experiments also showed that a reasonably accurate determination of the CH(4) production of a group of animals can be obtained by simply measuring the CH(4)/CO(2) ratio over a limited time span. This may represent the situation in a natural setting better than measurements in a respiration chamber. It was found that the CH(4)/CO(2) ratio in itself represents a reasonable prediction of the proportion of feed GE that is lost as CH(4), and that this method offers new opportunities for CH(4) measurements on a large number of animals.

Preservation of primordial follicles from lions by slow freezing and xenotransplantation of ovarian cortex into an immunodeficient mouse.

Assisted reproductive technology (ART) is considered an important tool in the conservation of endangered species, but often the most limiting factor of ART is the availability of mature oocytes. The aim of the present study was to investigate the feasibility of preserving female germ cells from ovaries of female lions (Panthera leo). Good quality cumulus-oocyte complexes (COCs) were isolated and subjected to in vitro maturation (IVM). In addition, ovarian cortex was obtained and cut into pieces for culture and cryopreservation by slow freezing. The survival of ovarian follicles was assessed by histology. Frozen-thawed samples of ovarian cortex samples were xenotransplanted under the skin of ovariectomized immunodeficient mouse for 28 days. Overall, 178 intact COCs were obtained from 13 lions, but only 28.1% were matured in vitro indicating insufficient IVM conditions. In contrast, almost all follicles within the ovarian cortex survived culture when the original sample was from a young healthy lion collected immediately after euthanasia. Within the xenotransplants, the number of primordial follicles decreased after 28 days by 20%, but the relation between primordial and growing follicles changed in favour of follicular growth. Female gamete rescue from valuable felids may be performed by slow freeze cryopreservation of ovarian cortex. Although the IVM protocol for lions is not yet optimized, mature oocytes may be obtained after long-term xenotransplantation and IVM and could potentially represent one way of salvage of endangered felid species in the future.