Characteristics of reproductive organs and reproductive potential in Scandinavian female grey wolves (Canis lupus).

The Swedish wolf population is closely monitored and managed to keep the population at a sustainable level while avoiding conflicts. Detailed knowledge about reproduction is crucial for estimates of population size and the reproductive potential of a population. Post-mortem evaluation of reproductive organs can be used as a complementary tool to field monitoring for evaluation of cyclicity and previous pregnancy, including litter size. Therefore, we evaluated reproductive organs from 154 female wolves that were necropsied during the period 2007-2018. The reproductive organs were weighed, measured, and inspected according to a standardised protocol. Presence of placental scars was evaluated for estimates of previous pregnancy and litter size. Data about individual wolves were also obtained from national carnivore databases. Body weight increased during the first year of life before levelling out. There was evidence of cyclicity the first season after birth in 16.3 % of the 1-year-old females. No females < 2 years had evidence of a previous pregnancy. Pregnancy rates were significantly lower in 2- and 3-year old females than in older females. Mean uterine litter size was 4.9 ± 2.3, and did not differ significantly between age groups. Our data supports earlier field data that female wolves usually start to reproduce at the earliest at 2-years of age but that they occasionally start to cycle one season earlier. All females ≥ 4 years of age had reproduced. Pathological findings of the reproductive organs were rare, indicating that reproductive health of female wolves is not a limiting factor for population growth.

Atypical porcine pestivirus-A widespread virus in the Swedish wild boar population.

The recently identified causative agent of congenital tremor in domestic piglets, atypical porcine pestivirus (APPV), was detected in serum from Swedish wild boar. A previous study from Sweden described APPV in domestic piglets suffering from congenital tremor, but the APPV situation in the wild boar population was unknown. In this study, 595 serum samples from wild boar originating from 13 counties in the south and central parts of Sweden, collected between 2000 and 2018, were analysed for the presence of the APPV-genome and for antibodies against the APPV-glycoprotein Erns . The results revealed that APPV is highly abundant in the Swedish wild boar population; 12% (73/595) were APPV-genome positive in serum and 72% (433/595) of the tested wild boars displayed APPV-specific antibodies. The present study also shows that APPV has been present in the Swedish wild boar population since at least the year 2000. The viral sequences obtained from the wild boars were highly similar to those obtained from Swedish domestic pigs positive for APPV and suffering from congenital tremor, suggesting a viral exchange between wild boars and domestic pigs. The high proportion of viraemic and seropositive wild boar is indicative of wild boar being an important reservoir for APPV.

Expression of IL-23 in gilt endometrium and oviduct after insemination with seminal plasma, spermatozoa or semen extender.

OBJECTIVE: Insemination with spermatozoa, seminal plasma and extender, cause a rapid inflammatory response in pig endometrium, characterized by an influx of neutrophils into the uterus. The transient inflammatory response to semen involves cytokine induction. Potential functions for Interleukin-23 (IL-23) in the inflammatory response to different insemination treatments were examined by studying mRNA expression and immunostaining in gilt oviduct and endometrium 35-40 h after insemination. Insemination was performed with seminal plasma (SP), spermatozoa (SPZ) without SP in the extender Beltsville thawing solution (BTS), or BTS alone. In control gilts an insemination catheter was inserted without anything being inseminated. RESULTS: Results showed that IL-23 mRNA was expressed in oviduct and endometrium after insemination regardless of treatment. There was an approximate two- to fourfold increase in expression of IL-23 mRNA in catheter-insertion control compared with SPZ, SP and BTS treatment groups. IL-23 immunolabelling was detected in a small number of separate cells and in the sub-epithelial connective tissue of the endometrium, the endosalpinx of isthmus and infundibulum. CONCLUSION: In conclusion, insemination with SP, SPZ in BTS, and BTS alone decreased the expression of IL-23 mRNA in the endometrium compared to catheter-insertion control, indicating a possible role for IL-23 in the inflammatory response after insemination in gilts.

Characteristics of reproductive organs and estimates of reproductive potential in Scandinavian male grey wolves (Canis lupus).

Improved knowledge about reproductive patterns and potential in male wolves (i.e., testicular development and size relative to age, pubertal age, and seasonal effects) is needed for evaluation and monitoring of reproductive outcomes in populations. Reproductive organs from 215 male wolves, culled as a result of licensed hunting, protective culling or from carcasses found were examined. The testes and epididymis were weighed and measured. There were biopsy samples collected from the testes and the cauda epididymis for histological determinations if there were spermatozoa in tissues collected. There were reproductive tissue analyses of 197 males while there were separate evaluations of tissues from ten cryptorchid animals. Juvenile wolves (< 1 year, n = 47) had a lesser body mass and mean testes mass than subadult (1-2 years, n = 71) and adult (>2 years, n = 79) males. Season also affected testicular characteristics of structures evaluated with subadult and adult males having a lesser mass during summer months (May-August). Of the 197 males, 70 % had spermatozoa in the seminiferous tubules and the cauda epididymis and were classified as being 'potentially fertile' when tissues were collected, while 22 % were classified as being non-fertile (no spermatozoa, including males that were pre-pubertal) and tissues of 8% could not be evaluated. When testes mass was greater, there was a greater likelihood that spermatozoa were present. There were seven of the ten cryptorchid males of the unilateral type. These testicular and epididymal findings will be useful for evaluating the reproductive potential and management of wolves in Scandinavia.

Dental disorders in sows from Swedish commercial herds.

Knowledge on dental disorders in commercial sows is limited although such conditions may have important animal welfare implications. In a pilot study, the dental and periodontal health of 58 sows (Landrace*Yorkshire-crosses) from 8 Swedish commercial pig herds, slaughtered at one abattoir, were investigated. The oral cavity was inspected and abnormalities were recorded on a dental chart modified for pigs. Dental abnormalities, absence of teeth, supernumerary teeth, tooth fractures, signs of caries, and malalignment were recorded. The study revealed that 19% of the sows had supernumerary teeth and 59% of the sows missed at least one tooth. Periodontitis, calculus and malalignment were observed in 33%, 45% and 17%, respectively. Tooth wear was very common both in incisors (total 83%) and in premolars/molars (total 84%). One or more tooth fractures (between 1 and 6 per sow) was found in 41%. Signs of caries was found in 9%. In order to assess oral health, three indices were used: calculus index (CI), periodontal index (PDI) and tooth wear index (TWI). Severe periodontitis, tooth wear in incisors and tooth wear in premolars/molars were found in 7%, 34% and 35%, respectively. With respect to animal welfare, the etiology and the effects of the disorders on health, stress and pain need to be investigated.

Vector-Borne Zoonotic Pathogens in Eurasian Moose (Alces alces alces).

Climate change, with warmer temperatures and altered precipitation patterns, has affected the distribution of vectors and vector-borne diseases. In the northern hemisphere, vectors are spreading north, and with them, pathogens of zoonotic and animal health impact. Eurasian moose (Alces alces alces) are physiologically and anatomically adapted for cold climate, and are rarely considered ideal hosts of vectors, apart from deer keds (Lipoptena cervi). To investigate the presence of vector-borne pathogens, spleen samples from 615 moose were collected in southern Sweden from 2008 to 2015. The samples were analyzed with a high-throughput PCR method for 24 bacterial, and 12 parasitic pathogens. Anaplasma (82%), Borrelia (3%), Babesia (3%), and Bartonella (1%) DNA was found, showing that moose are exposed to, and can act as hosts of some of these pathogens, which can have an impact of both animal and human health. These results show that Swedish moose are exposed to pathogens that in some instances are more commonly found in regions with warmer climate, and highlights the importance of also considering moose as sentinels of vector-borne pathogens. Further research is needed to understand the effect of these pathogens on the health of individual moose and to elucidate whether climate change and moose population density interact to create the pattern observed.

Serological survey in wild boar (Sus scrofa) in Switzerland and other European countries: Sarcoptes scabiei may be more widely distributed than previously thought.

BACKGROUND: Sarcoptic mange has recently emerged in wild boar in Switzerland, raising the question of the origin of the infection. The main aim of this study was to assess the extent of exposure of the wild boar populations to Sarcoptes scabiei in Switzerland, prior to and after the detection of mange cases, to determine whether the mite has been recently introduced into the populations concerned. We performed a serological survey using a commercially available ELISA and 1056 archived blood samples of free-ranging wild boar from Switzerland. To facilitate the interpretation of the obtained data, we additionally estimated seroprevalence in wild boar populations of four other European countries (1060 samples), both from areas with confirmed clinical cases of mange and from areas without reported cases in wild boar. Lastly, we revised the evaluation of the commercial ELISA when used with wild boar sera. RESULTS: Seropositive reactions were observed for samples from all five countries and from 15 of the 16 study areas. The obtained apparent seroprevalences ranged from 0.0% (0/82; 95% confidence interval [CI]: 0.0-4.4) to 17.4% (8/46; 95% CI: 7.8-31.4). Wild boar from study areas with known clinical cases and those ≤60 kg were four times more likely to be seropositive than wild boar from areas without reported cases and > 60 kg, respectively. Optical density values did not differ between the two types of study areas among seropositive samples but were significantly lower among seronegative samples from areas without than from areas with clinical cases. No difference was observed between the two sampling periods in Switzerland. The revised ELISA specificity was 96.8% (984/1017; 95% CI: 95.5-97.7) when wild boar from areas without history of mange were considered truly negative. CONCLUSIONS: Seropositivity to S. scabiei is more frequent and occurs over a larger geographic range than expected. Data suggest that the parasite is endemic within the wild boar populations of Switzerland and other European countries but that its presence is not necessarily associated with disease occurrence. Extrinsic factors which trigger disease emergence in infected populations remain to be investigated. The applied ELISA represents a promising tool for future studies.

A SEROLOGIC SURVEY OF PATHOGENS IN WILD BOAR ( SUS SCROFA) IN SWEDEN.

The wild boar ( Sus scrofa) population has increased markedly during the last three decades in Sweden and in other parts of Europe. This population growth may lead to increased contact between the wild boar and the domestic pig ( Sus scrofa scrofa), increasing the risk of transmission of pathogens. The objective of our study was to estimate the seroprevalence of selective pathogens, known to be shared between wild boars and domestic pigs in Europe, in three wild boar populations in Sweden. In total, 286 hunter-harvested female wild boars were included in this study. The sera were analyzed for antibodies against nine pathogens using different commercial or in-house enzyme-linked immunosorbent assays. Antibodies were detected against porcine parvovirus (78.0%), porcine circovirus type 2 (99.0%), swine influenza virus (3.8%), Erysipelothrix rhusiopathiae (17.5%), Mycoplasma hyopneumoniae (24.8%), and Toxoplasma gondii (28.6%). No antibodies were detected against porcine respiratory and reproductive syndrome virus, Brucella suis, or Mycobacterium bovis. Our results highlight the potential importance of the wild boar as a reservoir for pathogens potentially transmissible to domestic pigs and which also may affect human health.

The reproductive pattern and potential of free ranging female wild boars (Sus scrofa) in Sweden.

BACKGROUND: The number and spatial distribution of wild boars (Sus scrofa) has increased remarkably in Sweden as well as in other European countries. To understand the population dynamics of the wild boar, knowledge of its reproductive period, oestrus cycle and reproductive success is essential. The aim of this study was therefore to describe the seasonal reproductive pattern and reproductive potential of a wild boar population in Sweden. The study was based on findings from macroscopic examinations of the reproductive organs from 575 hunter-harvested female wild boars (>30 kg body weight). Samples were collected between December 2011 and December 2015 in the southern and middle parts of Sweden. The age of the sampled animals was determined and dressed weight was noted. The stage of the reproductive cycle was defined according to ovarian structures and in relation to the appearance of/and findings in the uterus. The crown-rump length (CRL) of the embryos/foetuses was used to calculate the oestrus/mating month and month for the expected farrowing. RESULTS: The macroscopic examination revealed a seasonal variation of reproductive stages, although cyclic and pregnant females were found in all seasons. Moreover, the estimated oestrus/mating and farrowing months based on the CRL showed that mating and farrowing may occur 'off-season'. The average litter size (no. of embryos or foetuses) per pregnant female was 5.4. Sow weight and age had significant effect on both the reproductive potential (ovulation rate and litter size) and pregnancy rate, respectively. CONCLUSIONS: The reproductive potential in the studied wild boar population was high compared to studies from other countries and farrowing may occur 'off-season'. This suggests that the environmental conditions in Sweden, including supplemental feeding, are favourable for wild boar reproduction.

Post-mortem examination of the reproductive organs of female wild boars (Sus scrofa) in Sweden.

In recent decades, wild boars (Sus scrofa) have increased in numbers and distribution in Europe. Compared to other wild ungulates of similar body size, wild boars have a high reproductive capacity. To increase the knowledge of wild boar reproduction, the objective of this study was to investigate characteristics of reproductive organs, and to provide information on the occurrence of abnormalities in reproductive organs from free-ranging female wild boars. Between December 2011 and December 2015, reproductive organs from female wild boars (>30 kg body weight), were collected during hunting in four Swedish counties at estates where supplementary feeding was applied. The organs were macroscopically examined and measured. The stage of the reproductive cycle was defined according to the ovarian structures and in relation to uterus characteristics. Observed abnormalities were noted. The results from 569 animals that met the requirements to be included in this study showed significant differences in weight and length of the uterus between the various reproductive stages. Sampling region had significant effect on these differences. Abnormalities in the reproductive organs were present in approximately 10% of the examined animals. The prevalence of abnormalities increased significantly with age and was significantly affected by sampling region.

Puberty in female wild boar (Sus scrofa) in Sweden.

BACKGROUND: Since the re-appearance of wild boars in Sweden in the 1970s, the population has increased. Besides having large litter sizes, puberty at an early age is considered as an important factor contributing to the high reproductive potential of wild boar. Although controversial, supplemental feeding is applied to varying extent throughout the wild boar range in Sweden, and its effect on wild boar reproduction is debated. The aim of this study was to investigate the proportion of post-pubertal female wild boar gilts in a population subjected to supplemental feeding, in relation to age, weight, and season. Also, the effect of another definition of puberty (based upon follicular size) on the outcome of the proportion of female wild boar gilts considered to be able to reproduce in a population was illustrated. Between Jan 2013 and Dec 2015 reproductive organs from 592 female wild boars, were collected. Ovaries and uterus were macroscopically examined, and reproductive stage was determined by the presence of ovarian structures and uterus characteristics. Age was estimated using tooth eruption and tooth replacement, and weight was noted. A subset of 175 female wild boars, aged 5-15 months, was included in this study. An animal was considered to be post-pubertal if the ovaries contained one or more corpora lutea (CL) or if the uterus showed signs of previous pregnancy (presence of enlarged blood vessels in the cut surface between the mesometric ligament and the uterus). RESULTS: In total, 29 (16.6 %) animals were classified as post-pubertal. Field dressed weight ranged from 20.6 to 65.3 kg. Season, weight, and age class significantly influenced the variation in proportion of post-pubertal females. Post-pubertal animals were found in autumn, winter, and spring, but not in the summer season. Another definition of puberty, based on follicle size, lead to different result on proportions of animals considered to have passed puberty. CONCLUSIONS: Season, weight, and age significantly influenced the variation in proportion of post-pubertal wild boar females. The proportion of post-pubertal animals increased with age and weight. However, weight is probably a better proxy for puberty than age group is. The proportion of post-pubertal females also increased from summer to spring suggesting a seasonal reproductive pattern. Different definitions of puberty will result in various outcomes, which high-lights the importance of using adequate definition of puberty.

Serologic and Molecular Prevalence of Rickettsia helvetica and Anaplasma phagocytophilum in Wild Cervids and Domestic Mammals in the Central Parts of Sweden.

Both Rickettsia helvetica and Anaplasma phagocytophilum are common in Ixodes ricinus ticks in Sweden. Knowledge is limited regarding different animal species' competence to act as reservoirs for these organism. For this reason, blood samples were collected from wild cervids (roe deer, moose) and domestic mammals (horse, cat, dog) in central Sweden, and sera were tested using immunofluorescence assay to detect antibodies against spotted fever rickettsiae using Rickettsia helvetica as antigen. Sera with a titer ≥1:64 were considered as positive, and 23.1% (104/450) of the animals scored positive. The prevalence of seropositivity was 21.5% (23/107) in roe deer, 23.3% (21/90) in moose, 36.5% (23/63) in horses, 22.1% (19/90) in cats, and 17.0% (17/100) in dogs. PCR analysis of 113 spleen samples from moose and sheep from the corresponding areas were all negative for rickettsial DNA. In roe deer, 85% (91/107) also tested seropositive for A. phagocytophilum with a titer cutoff of 1:128. The findings indicate that the surveyed animal species are commonly exposed to rickettsiae and roe deer also to A. phagocytophilum.

High prevalence of hepatitis e virus in Swedish moose--a phylogenetic characterization and comparison of the virus from different regions.

BACKGROUND: Hepatitis E virus (HEV) infects a range of species, including humans, pigs, wild boars and deer. Zoonotic transmission may contribute to the high HEV seroprevalence in the human population of many countries. A novel divergent HEV from moose (Alces alces) in Sweden was recently identified by partial genome sequencing. Since only one strain was found, its classification within the HEV family, prevalence in moose and zoonotic potential was unclear. We therefore investigated samples from 231 moose in seven Swedish counties for HEV, and sequenced a near complete moose HEV genome. Phylogenetic analysis to classify this virus within the family Hepeviridae and to explore potential host specific determinants was performed. METHODS AND FINDINGS: The HEV prevalence of moose was determined by PCR (marker for active infection) and serological assays (marker of past infection) of sera and 51 fecal samples from 231 Swedish moose. Markers of active and past infection were found in 67 (29%) animals, while 34 (15%) were positive for HEV RNA, 43 (19%) were seropositive for anti-HEV antibodies, and 10 (4%) had both markers. The number of young individuals positive for HEV RNA was larger than for older individuals, and the number of anti-HEV antibody positive individuals increased with age. The high throughput sequenced moose HEV genome was 35-60% identical to existing HEVs. Partial ORF1 sequences from 13 moose strains showed high similarity among them, forming a distinct monophyletic clade with a common ancestor to HEV genotype 1-6 group, which includes members known for zoonotic transmission. CONCLUSIONS: This study demonstrates a high frequency of HEV in moose in Sweden, with markers of current and past infection demonstrated in 30% of the animals. Moose is thus an important animal reservoir of HEV. The phylogenetic relationship demonstrated that the moose HEV belonged to the genotype 1-6 group, which includes strains that also infect humans, and therefore may signify a potential for zoonotic transmission of this HEV.

Characteristics of spermatozoa and reproductive organs in relation to age and body weight in Swedish moose (Alces alces).

Knowledge of the reproductive biology of game species is vital for sustainable management. In moose (Alces alces), research in reproductive characteristics has focused on the female, whereas there are few studies in male moose. The aim of the present study was to investigate sperm morphology and chromatin integrity (SCSA), and their relationships with testicular and epididymal features, as well as temporal aspects with respect to the hunting season. In total, 143 male moose aged 1.5-11.5 years were sampled from 2008 to 2011. The proportion of normal spermatozoa (PNS) ranged from 1.5% to 82.0%, with a mean of 51%, and the %DFI (DNA fragmentation index) ranged from 2.5% to 36.7% (mean 9.5). PNS decreased temporally, and was positively associated with carcass and testes weight. Body weight and testes weight had positive effect on PNS regardless of age. No effect of any explanatory variables was observed on the DFI. The testis/body weight ratio of moose (0.033%) is among the lowest reported among mammals, indicating a less polygynous mating system than in roe deer and red deer. For reproduction success in moose, a high body weight in males is favorable, as is a balanced sex ratio. Thus, males should not be harvested prior to the time when the majority of females have passed their first oestrus of the season.

Surveys on Coxiella burnetii infections in Swedish cattle, sheep, goats and moose.

BACKGROUND: Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Prevalence data in ruminant species are important to support risk assessments regarding public and animal health. The aim was to investigate the presence of or exposure to C. burnetii in cattle, sheep, goats and moose, and to compare two enzyme-linked immunosorbent assays (ELISAs). National surveys of antibodies against C. burnetii were performed for dairy cattle (n=1537), dairy goats (n=58) and sheep (n=518). Bovine samples consisted of bulk milk, caprine of pooled milk, and ovine of pooled serum. Antibodies were investigated in moose samples (n=99) from three regions. A one-year regional cattle bulk milk survey was performed on the Isle of Gotland (n=119, four occasions). Cattle, sheep and goat samples were analysed with indirect ELISA and moose samples with complement fixation test. For the sheep, goat, and parts of the cattle survey, samples were run in parallel by ELISAs based on antigens from infected ruminants and ticks. Bulk milk samples from the regional cattle survey and vaginal swabs from a subset of the sheep herds (n=80) were analysed for the agent by polymerase chain reaction. Spatial clustering was investigated in the national cattle survey. RESULTS: The prevalence of antibodies in dairy herds was 8.2% with large regional differences. High risk clusters were identified in the southern regions. The prevalence among dairy herds on the Isle of Gotland varied from 55.9% to 64.6% and 46.4% to 58.9.0% for antibodies and agent, respectively, overall agreement between agent and antibodies was 85.2%. The prevalence of antibodies in sheep was 0.6%, the agent was not detected the vaginal swabs. Antibodies were not detected in goats or moose, although parts of the moose samples were collected in an area with high prevalence in cattle. The overall agreement between the two ELISAs was 90.4%. CONCLUSIONS: The prevalence of antibodies against C. burnetii in dairy cattle in Sweden shows large regional differences. The results suggest that C. burnetii is a rare pathogen among Swedish moose, dairy goat and sheep. ELISAs based on ruminant and tick antigen performed in a similar manner under Swedish conditions.

Reproductive failure in moose (Alces alces) due to embryonic mortality and unfertilized oocytes.

Knowledge on reproductive success is vital for successful management of large ungulates and is often measured by means of observing surviving offspring. In harvested ungulates, postmortem investigations of reproductive organs are used to estimate reproductive potential by obtaining ovulation rates and fetus numbers. However, there are differences in numbers of offspring observed, fetal/embryo counts, and ovulation rates. We hypothesize that the discrepancy between estimated reproductive potential and reproductive outcome in large ungulates is not only due to ova loss but also due to embryonic mortality. We investigated reproductive status in early pregnancy by sampling hunter-harvested moose (Alces alces) in southern Sweden from 2007 to 2011. In all, 213 reproductive organs were examined postmortem, and in confirmed pregnant moose (n = 53), 25 % (19 of 76) embryos were nonviable and 6 % of ova was unfertilized. The discrepancy between the ovulation rate of all pregnant moose (1.49) and the number of expected offspring per pregnant female, when embryonic mortality and unfertilized oocytes were accounted for (1.08), was 27.5 %. An association between inflammation of the inner mucous membrane (endometritis) of the moose's uterus and embryonic mortality was observed. This is the first comprehensive report of embryonic mortality and endometritis in moose. The observed discrepancy between ovulation rates and early embryonic development/survival shows that ovulation rates are indicative but not accurate estimates of moose reproductive rate. The use of ovulation rates as a sole estimator of future offspring rates may lead to an overharvest of a managed moose population.

A 25 years experience of group-housed sows-reproduction in animal welfare-friendly systems.

Since January 1 2013, group housing of sows has been compulsory within the European Union (EU) in all pig holdings with more than ten sows. Sows and gilts need to be kept in groups from 4 weeks after service to 1 week before the expected time of farrowing (Article 3(4) of Directive 2008/120/EC on the protection of pigs). The legislation regarding group housing was adopted already in 2001 and a long transitional period was allowed to give member states and producers enough time for adaptation. Even so, group housing of sows still seems to be uncommon in the EU, and is also uncommon in commercial pig farming systems in the rest of the world. In this review we share our experience of the Swedish 25 years of animal welfare legislation stipulating that sows must be loose-housed which de facto means group housed. The two most important concerns related to reproductive function among group-housed sows are the occurrence of lactational oestrus when sows are group-housed during lactation, and the stress that is associated with group housing during mating and gestation. Field and clinical observations in non-lactating, group-housed sows in Sweden suggest that by making basic facts known about the pig reproductive physiology related to mating, we might achieve application of efficient batch-wise breeding without pharmacological interventions. Group housing of lactating sows has some production disadvantages and somewhat lower productivity would likely have to be expected. Recordings of behavioural indicators in different housing systems suggest a lower welfare level in stalled animals compared with group-housed ones. However, there are no consistent effects on the reproductive performance associated with different housing systems. Experimental studies suggest that the most sensitive period, regarding disturbance of reproductive functions by external stressors, is the time around oestrus. We conclude that by keeping sows according to the pig welfare-friendly Directive 2008/120/EC, it is possible to combine group-housing of sows with good reproductive performance and productivity. However, substantially increased research and development is needed to optimize these systems.

Reproductive characteristics in female Swedish moose (Alces alces), with emphasis on puberty, timing of oestrus, and mating.

BACKGROUND: The moose (Alces alces) is an intensively managed keystone species in Fennoscandia. Several aspects of reproduction in moose have not been fully elucidated, including puberty, timing of mating and oestrus, and the length of the oestrus period. These aspects are relevant for an adaptive management of moose with respect to harvest, population size, demography and environmental conditions. Therefore, an investigation of female moose reproduction was conducted during the moose-hunting period in southern Sweden from 2008 to 2011. RESULTS: A total of 250 reproductive organs and information on carcass weight and age was collected from four different hunting areas (provinces of Öland, Småland, Södermanland, and Västergötland) in southern Sweden. The results showed that puberty in female moose varied with carcass weight, age, and time of season. The period for oestrous/mating lasted from about mid September to the beginning of November. CONCLUSIONS: The oestrus period (predominantly for heifers) is longer than previously reported and was not finished when the hunting period started. Sampling the uterine cervix to detect spermatozoa was a useful method to determine if mating had occurred. To avoid hunting of moose during oestrus, we suggest that the hunting period should be postponed by at least 14 days in southern Sweden.

Stallion spermatozoa selected by single layer centrifugation are capable of fertilization after storage for up to 96 h at 6°C prior to artificial insemination.

BACKGROUND: One of the challenges faced by equine breeders is ensuring delivery of good quality semen doses for artificial insemination when the mare is due to ovulate. Single Layer Centrifugation (SLC) has been shown to select morphologically normal spermatozoa with intact chromatin and good progressive motility from the rest of the ejaculate, and to prolong the life of these selected spermatozoa in vitro. The objective of the present study was a proof of concept, to determine whether fertilizing ability was retained in SLC-selected spermatozoa during prolonged storage. FINDINGS: Sixteen mares were inseminated with SLC-selected sperm doses that had been cooled and stored at 6°C for 48 h, 72 h or 96 h. Embryos were identified in 11 mares by ultrasound examination 16-18 days after presumed ovulation. CONCLUSION: SLC-selected stallion spermatozoa stored for up to 96 h are capable of fertilization.

Steroid hormone receptors ERalpha and PR characterised by immunohistochemistry in the mare adrenal gland.

BACKGROUND: Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function. METHODS: In the present study, immunohistochemistry using two different mouse monoclonal antibodies was employed to determine the presence of oestrogen receptor alpha (ERalpha) and progesterone receptor (PR) in the mare adrenal gland. Adrenal glands from intact (n = 5) and ovariectomised (OVX) (n = 5) mares, as well as uterine tissue (n = 9), were collected after euthanasia. Three of the OVX mares were treated with a single intramuscular injection of oestradiol benzoate (2.5 mg) 18-22 hours prior to euthanasia and tissue collection (OVX+Oe). Uterine tissue was used as a positive control and showed positive staining for both ERalpha and PR. RESULTS: ERalpha staining was detected in the adrenal zona glomerulosa, fasciculata and reticularis of all mare groups. Ovariectomy increased cortical ERalpha staining intensity. In OVX mares and one intact mare, positive ERalpha staining was also detected in adrenal medullary cells. PR staining of weak intensity was present in a low proportion of cells in the zona fasciculata and reticularis of all mare groups. Weak PR staining was also found in a high proportion of adrenal medullary cells. In contrast to staining in the adrenal cortex, which was always located within the cell nuclei, medullary staining for both ERalpha and PR was observed only in the cell cytoplasm. CONCLUSION: The present results show the presence of ERalpha in the adrenal cortex, indicating oestradiol may have a direct effect on mare adrenal function. However, further studies are needed to confirm the presence of PR as staining in the present study was only weak and/or minor. Also, any possible effect of oestradiol treatment on the levels of steroid receptors cannot be determined by the present study, as treatment time was of a too short duration.