RhoA/ROCK signaling antagonizes bovine trophoblast stem cell self-renewal and regulates preimplantation embryo size and differentiation.

Exponential proliferation of trophoblast stem cells (TSC) is crucial in Ruminantia to maximize numerical access to caruncles, the restricted uterine sites that permit implantation. When translating systems biology of the undifferentiated bovine trophectoderm, we uncovered that inhibition of RhoA/Rock promoted self-renewing proliferation and substantially increased blastocyst size. Analysis of transcripts suppressed by Rock inhibition revealed transforming growth factor ß1 (TGFß1) as a primary upstream effector. TGFß1 treatment induced changes consistent with differentiation in bTSCs, a response that could be replicated by induced expression of the bovine ROCK2 transgene. Rocki could partially antagonize TGFß1 effects, and TGFß receptor inhibition promoted proliferation identical to Rocki, indicating an all-encompassing upstream regulation. Morphological differentiation included formation of binucleate cells and infrequent multinucleate syncytia, features we also localize in the in vivo bovine placenta. Collectively, we demonstrate a central role for TGFß1, RhoA and Rock in inducing bTSC differentiation, attenuation of which is sufficient to sustain self-renewal and proliferation linked to blastocyst size and preimplantation development. Unraveling these mechanisms augments evolutionary/comparative physiology of the trophoblast cell lineage and placental development in eutherians.

The uterine secretory cycle: recurring physiology of endometrial outputs that setup the uterine luminal microenvironment.

Conserved in female reproduction across all mammalian species is the estrous cycle and its regulation by the hypothalamic-pituitary-gonadal (HPG) axis, a collective of intersected hormonal events that are crucial for ensuring uterine fertility. Nonetheless, knowledge of the direct mediators that synchronously shape the uterine microenvironment for successive yet distinct events, such as the transit of sperm and support for progressive stages of preimplantation embryo development, remain principally deficient. Toward understanding the timed endometrial outputs that permit luminal events as directed by the estrous cycle, we used Bovidae as a model system to uniquely surface sample and study temporal shifts to in vivo endometrial transcripts that encode for proteins destined to be secreted. The results revealed the full quantitative profile of endometrial components that shape the uterine luminal microenvironment at distinct phases of the estrous cycle (estrus, metestrus, diestrus, and proestrus). In interpreting this comprehensive log of stage-specific endometrial secretions, we define the "uterine secretory cycle" and extract a predictive understanding of recurring physiological actions regulated within the uterine lumen in anticipation of sperm and preimplantation embryonic stages. This repetitive microenvironmental preparedness to sequentially provide operative support was a stable intrinsic framework, with only limited responses to sperm or embryos if encountered in the lumen within the cyclic time period. In uncovering the secretory cycle and unraveling realistic biological processes, we present novel foundational knowledge of terminal effectors controlled by the HPG axis to direct a recurring sequence of vital functions within the uterine lumen.NEW & NOTEWORTHY This study unravels the recurring sequence of changes within the uterus that supports vital functions (sperm transit and development of preimplantation embryonic stages) during the reproductive cycle in female Ruminantia. These data present new systems knowledge in uterine reproductive physiology crucial for setting up in vitro biomimicry and artificial environments for assisted reproduction technologies for a range of mammalian species.

First Kiso pony foal produced via transfer of long-distance shipped fresh embryo to Hokkaido native pony.

Japanese native horses, which consists of 8 breeds, are threatened with extinction. Embryo transfer (ET) is used to reproduce endangered animals in various mammalian species. We aimed to perform ET using native ponies from Kiso and Hokkaido as donors and recipients, respectively. ET operation included long-distance transport of non-cryopreserved embryos from Nagano Prefecture to Hokkaido. Embryos were transported 1500 km over 9 h in a container maintained at 22°C. After transferring two embryos to two recipients, one mare delivered a healthy live foal. These results demonstrated that reciprocal ET with long-distance transportation of fresh embryos between the isolated breeds may allow for the proliferation of Japanese native horses.

Canine intrahepatic portosystemic shunts: Interlobar and intralobar classifications.

This two-part study design showed that a canine congenital intrahepatic portosystemic shunt (IPSS) may be classified by its location within a liver fissure (interlobar) or lobe (intralobar). A prospective anatomic study reviewed normal canine liver morphology and showed the CT angiography (CTA) appearance of the normal canine ductus venosus (DV), which was confirmed via dissection and literature review to be between the papillary process and left-lateral liver lobe (in the fissure for ligamentum venosum). A retrospective multi-institutional case series documented the frequency of imaging findings in 56 dogs with a single IPSS that underwent portal CTA at Cornell University or the Schwarzman Animal Medical Center between June 2008 and August 2022. An interlobar IPSS was seen in 24 of 56 (43%) dogs, all arose from the left portal branch except one. These shunts were typically near the median plane, remained interlobar throughout the course, and were nearly always (96%) craniodorsal to the porta hepatis. Four types were distinguished: patent DV (11 dogs), left interlobar (11 dogs), right interlobar (1 dog), and ventral interlobar (1 dog). Only about half (46%) were in the fissure for ligamentum venosum and therefore classified as a patent DV. An intralobar IPSS was seen in 32 of 56 (57%) dogs, most (88%) originated from the right portal branch and were in the right-lateral liver lobe (21 dogs) or caudate process (7 dogs). During canine portal CTA, documenting the interlobar or intralobar location of an IPSS might increase the consistency and validity of IPSS description.

Rheotaxis-based separation of sperm with progressive motility using a microfluidic corral system.

The separation of motile sperm from semen samples is sought after for medical infertility treatments. In this work, we demonstrate a high-throughput microfluidic device that can passively isolate motile sperm within corrals inside a fluid channel, separating them from the rest of the diluted sample. Using finite element method simulations and proposing a model for sperm motion, we investigated how flow rate can provide a rheotaxis zone in front of the corral for sperm to move upstream/downstream depending on their motility. Using three different flow rates that provided shear rates above the minimum value within the rheotaxis zone, we experimentally tested the device with human and bovine semen. By taking advantage of the rheotactic behavior of sperm, this microfluidic device is able to corral motile sperm with progressive velocities in the range of 48-93 µm⋅s-1 and 51-82 µm⋅s-1 for bovine and human samples, respectively. More importantly, we demonstrate that the separated fractions of both human and bovine samples feature 100% normal progressive motility. Furthermore, by extracting the sperm swimming distribution within the rheotaxis zone and sperm velocity distribution inside the corral, we show that the minimum velocity of the corralled sperm can be adjusted by changing the flow rate; that is, we are able to control the motility of the separated sample. This microfluidic device is simple to use, is robust, and has a high throughput compared with traditional methods of motile sperm separation, fulfilling the needs for sperm sample preparation for medical treatments, clinical applications, and fundamental studies.

Evaluating the use of piezo manipulator, laser or their combination for blastocoel cavity puncture to improve cryopreservation outcomes of large equine embryos.

The main difficulty of large equine embryo cryopreservation is the replacement of blastocoel fluid with cryoprotectant solution. The objective of this study was to improve the cryopreservation of large equine embryos with PMAP and/or LAP. Embryos were collected via the non-surgical transcervical procedure and divided into three groups based on their size (A ≤ 300 µm, 300 µm300 µm). However, more research is required to find the best method for embryos ≥700 µm.

Birth of first foals through embryo transfer after artificial insemination using frozen semen in Japan.

Until now, there have been no reports of foals born through embryo transfer after artificial insemination using frozen semen in Japan. The aims of this study were to develop a riding crossbred horse and evaluate the prospects of embryo transfer technology in multiplying horse population. In both donor and recipient mares, luteolysis was induced by the administration of 0.1 mg Cloprostenol to synchronize the onset of estrus, and ovulation was induced by administering 2000 IU human chorionic gonadotropin (hCG) or 0.75 mg Deslorelin. Frozen semen from an Irish Connemara pony stallion was used to breed a Hokkaido native pony mare by deep-horn artificial insemination (dose, 400 × 106 sperm). A non-surgical technique was used to collect embryos from the donor mare at day 7 post-ovulation and transfer them transcervically into the uterus of recipient mares (n = 4) immediately after collection. Weekly blood samples were collected from the recipients throughout pregnancy. A total of four embryos were recovered from seven collection attempts (57% recovery) from a donor mare in a single breeding season. Three of the four transferred embryos maintained successful pregnancy and delivered a healthy live foal (75% birth). A normal progesterone profile was observed throughout gestation in recipient mares. In conclusion, for the first time, to the best of our knowledge, this study describes the birth of foals through non-surgical transcervical embryo transfer in Japan after artificial insemination using frozen semen. We expect that this new crossbreed (Connemara pony × Hokkaido native pony) will be a good riding breed.

Uterine perforation secondary to metritis and placenta percreta in a postpartum bitch.

A 3-year-old intact female Labradoodle bitch was referred due to fever and lethargy 4 days postpartum. The dog was reported to have had prolonged labor that required assistance and fetal membranes were retained. Physical examination and diagnostics led to a suspicion of metritis and uterine perforation. Ovariohysterectomy was performed. Gross and histopathology findings revealed multifocal uterine perforation, necrosuppurative metritis, and placenta percreta. Post-operative antibiotic therapy and supportive care resulted in an uneventful clinical recovery. This is the first reported case of placenta percreta in a bitch. It is presumed that this pathology was paramount in the patient's development of metritis and subsequent uterine rupture. Key clinical message: Placenta percreta may lead to more severe clinical consequences of metritis, including uterine rupture.

Perforation utérine secondaire à une métrite et un placenta percreta chez une chienne en période post-partum. Une femelle Labradoodle intacte âgée de 3 ans fut référée pour cause de fièvre et léthargie 4 jours post-partum. Il fut rapporté que la chienne avait eu un travail long qui demanda de l'assistance et qu'il y avait eu rétention des membranes foetales. L'examen physique et le diagnostic mena à un doute de métrite et de perforation utérine. Une ovario-hystérectomie fut réalisée. Les trouvailles de pathologie macroscopique et d'histopathologie révélèrent des perforations utérines multifocales, une métrite nécro-suppurative et un placenta percreta. Une antibiothérapie post-opératoire et des soins de support ont résulté en une guérison clinique sans conséquence. Ceci représente le premier cas rapporté de placenta percreta chez une chienne. Il est présumé que chez cette chienne cette pathologie était vitale dans le développement de la métrite et de la rupture utérine subséquente.Message clinique clé :Un placenta percreta peut mener à des conséquences cliniques plus sévères de métrite, incluant la rupture utérine.(Traduit par Dr Serge Messier).

Colostral and foal serum immunoglobulin G levels and associations with perinatal abnormalities in heavy draft horses in Japan.

The purpose of this study was to elucidate the colostral and foal serum immunoglobulin G (IgG) concentration values in heavy draft horses in Japan and to examine the effects of peripartum mare condition on colostral immunity. Colostrum was obtained 1 hr after foaling (pre-suckling; n=178). Blood was collected from the jugular vein of the foals (n=147) at 24 to 48 hr after birth. The foaling statuses of 73 mares were recorded. The average colostral IgG concentration was 10,540 ± 3,190 mg/dl (median=10,928; range 1,434-17,514 mg/dl). The average serum IgG concentration obtained from neonatal foals 24 to 48 hr after birth was 1,750 ± 919 mg/dl (median=1,890; range 0-3,510 mg/dl). Although colostral IgG did not differ between the normal foaling mare (n=59) and dystocial mare (n=14), foal serum IgG was lower in foals born in dystocia than in foals in normal foaling (P<0.05). This study demonstrates reference values for colostral and foal serum IgG specific to heavy draft horses in Japan and suggests that dystocia may interfere with the acquisition of colostral immunity in neonatal foals.

A retrospective analysis of the epidural use of bupivacaine 0.0625-0.125% with opioids in bitches undergoing cesarean section.

Epidural anesthesia, often used during cesarean surgery, can exacerbate hypotension from general anesthesia and delay discharge due to motor block. Decreasing the local anesthetic dose might reduce those complications. Cases of dogs undergoing cesarean section that were anesthetized without epidural (n = 29) (control) and dogs with low-dose epidural bupivacaine with fentanyl or buprenorphine (n = 37) were reviewed. The incidence of hypotension was equal between groups. Intraoperative opioids were administered more to control (93%) than to treated dogs (18%; P < 0.0001). Epidural bupivacaine 0.0625-0.125% combined with an opioid reduced the use of intraoperative opioids and did not exacerbate arterial hypotension during cesarean section in anesthetized dogs.

Analyse rétrospective de l'utilisation de bupivacaine 0,0625­0,125 % avec des opioïdes lors d'épidurale chez des chiennes soumises à une césarienne. L'anesthésie épidurale, souvent utilisée lors d'une césarienne, peut exacerber l'hypotension due à l'anesthésie générale et retarder le congé à cause d'un bloc moteur. Une diminution de la dose d'anesthésique local pourrait réduire ces complications. Une revue fut effectuée des cas de chiennes soumises à une césarienne et anesthésiées sans épidurale (n = 29) (témoin) et des chiennes avec une épidurale en utilisant une faible dose de bupivacaine avec du fentanyl ou de la buprenorphine (n = 37). L'incidence d'hypotension était égale entre les groupes. Des opioïdes intra-opératoires furent administrés plus fréquemment chez les témoins (93 %) que chez les animaux traités (18 %; P < 0,001). De la bupivacaine 0,0625­0,125 % en épidurale combinée à un opioïde réduisit l'utilisation d'opioïdes intra-opératoires et n'a pas exacerbé l'hypotension artérielle durant la césarienne chez des chiennes anesthésiées.(Traduit par Dr Serge Messier).

Bilateral granulosa cell tumor in a cycling mare.

A 16-year-old Oldenburg mare was evaluated for stallion-like behavior. The mare had given birth to 2 foals previously. Transrectal palpation revealed bilaterally enlarged ovaries with no palpable ovulation fossa. Ultrasound examination showed both ovaries to have small follicles giving a honeycomb appearance, concurrent with a single large cystic structure in the left ovary (10.2 cm diameter). Serum Anti-Müllerian hormone (AMH) was elevated (95.7 pmol/L), consistent with granulosa cell tumor (GCT). Both ovaries were removed via flank laparoscopy and were evaluated by histopathology, which confirmed bilateral GCT and concurrent presence of fresh luteal tissue, demonstrating the unusual presentation of bilateral granulosa cell tumor in a cycling mare.

Tumeur bilatérale de la granulosa chez une jument en cycle. Une jument Oldenburg âgée de 16 ans a été évaluée pour un comportement s'apparentant à celui d'un étalon. La jument avait précédemment donné naissance à deux poulains. La palpation transrectale a révélé des ovaires élargis bilatéralement sans fosse d'ovulation palpable. L'échographie a indiqué que les deux ovaires avaient de petits follicules à l'apparence de nid d'abeilles ainsi qu'une seule grande structure cystique dans l'ovaire gauche (diamètre de 10,2 cm). L'hormone antimllérienne (HAM) était élevée (95,7 pmol/L), conformément à une tumeur de la granulosa (TG). Les deux ovaires ont été enlevés par laparascopie du flanc et ils ont été évalués par histopathologie qui a confirmé les TG bilatérales et la présente concomitante de tissu lutéal frais, ce qui démontre la présentation inusitée des tumeurs granulosa bilatérales chez une jument en cycle.(Traduit par Isabelle Vallières).

Successful management of hydrallantois in a Standardbred mare at term resulting in the birth of a live foal.

A 6-year-old Standardbred mare was presented at 339 days of gestation for investigation of abnormal abdominal distension and ventral edema. Transrectal palpation and ultrasound examination revealed the uterus to be enlarged with an excessive volume of fetal fluid, characteristic of hydrops. Gradual transcervical drainage of 55 L of allantoic fluid over 45 minutes, with concurrent intravenous fluid therapy followed by assisted vaginal delivery, resulted in the birth of a live foal with long-term survival. The birth and long-term survival of a foal from a mare with hydrallantois at term has not been previously reported in horses. However, this report demonstrates that successful outcome for both mare and foal may be achieved in a mare at term with hydrallantois.

Gestion réussie de l'hydrallantois chez une jument Standardbred à terme donnant lieu à la naissance d'un poulain vivant. Une jument Standardbred âgée de 6 ans a été présentée à 339 jours de gestation pour investiguer une distension abdominale anormale et un oedème ventral. La palpation transrectale et l'échographie ont révélé que l'utérus était enflé en raison d'un volume excessif de liquide foetal, ce qui est caractéristique de l'hydrops fetalis. Un drainage transcervical graduel de 55 L de liquide allantoïdien pendant plus de 45 minutes et une fluidothérapie par intraveineuse suivis d'une mise bas vaginale assistée ont donné lieu à la naissance d'un poulain vivant avec survie à long terme. La naissance et la survie à long terme d'un poulain provenant d'une jument atteinte de l'hydrallantois à terme n'avaient pas été précédemment signalées chez les chevaux. Cependant, des résultats fructueux pour la jument et le poulain peuvent être obtenus chez une jument atteinte d'hydrallantois à terme.(Traduit par Isabelle Vallières).

Metabolic and Endocrine Differences Between Dairy Cows That Do or Do Not Ovulate First Postpartum Dominant Follicles.

Most dairy cows develop the first dominant follicle postpartum within 2 wk after calving, but only about 40% of these follicles produce sufficient estradiol to stimulate ovulation despite having normal ultrasound appearance and growth. This study aimed to characterize metabolic, endocrine, and follicular fluid profiles of cows in which the first dominant follicle postpartum will become ovulatory and those with nonovulatory follicles. Luteinizing hormone pulse frequency, follicular fluid androstenedione, and follicular fluid estradiol concentrations were lower in nonovulatory cows suggesting that the function of theca cells is impaired. In addition, nonovulatory cows had more severe negative energy balance and greater insulin resistance postpartum. This study describes for the first time the steroid hormone profile of early postpartum follicles and shows that a steroidogenic defect most likely occurs in theca cells limiting the amount of androgen precursor available for estradiol production that impairs their ovulatory outcome.

Massive vulvar edema in 2 prepartum dairy cows.

Two late gestation Holstein cows about to begin the third lactation developed massive vulvar edema. These were the only affected animals in the herd of 500 milking cows. The vulvar edema spontaneously regressed postpartum for both cows. Massive vulvar swelling is seldom observed in dairy cows in advanced pregnancy and is not described in the literature.

Edème vulvaire massif chez deux vaches laitières prépartum. Deux vaches Holstein en fin de gestation s'apprêtant à commencer la troisième lactation ont développé un œdème vulvaire massif. Il s'agissait des seuls animaux touchés dans le troupeau de 500 vaches laitières. L'œdème vulvaire a spontanément régressé postpartum pour les deux vaches. L'enflure vulvaire massive est rarement observée chez les vaches laitières aux stades avancés de la gestation et elle n'est pas décrite dans la littérature.(Traduit par Isabelle Vallières).

Inflammatory markers for differentiation of endometritis in the mare.

BACKGROUND: Endometrial biopsy is required to diagnose mares with chronic endometritis and endometrial degenerative fibrosis. An increase in understanding of equine reproductive immunology could be utilised to create less-invasive, time-efficient diagnostic tools especially when evaluating mares for chronic endometritis. OBJECTIVES: To evaluate inflammatory cytokine and chemokine concentrations in uterine fluid samples collected by low-volume lavage (LVL) as a potential screening diagnostic biomarker for endometritis. STUDY DESIGN: Prospective cross-sectional clinical study. METHODS: Forty-six mares underwent a LVL and subsequently endometrial biopsy. Mares were split in three groups: healthy, acute endometritis, and chronic endometrial fibrosis (CEF) based on cytological and histological evaluation. A fluorescent bead-based multiplex assay for IFN-γ, IFN-α, IL-1ß, IL-4, IL-10, IL-17, sCD14, TNF-α, CCL2, CCL3, CCL5 and CCL11 were carried out on the LVL fluid. The endometrial biopsy was utilised for histology and qPCR of IFN-γ, IL-1ß, IL-6, IL-8, IL-17, TNF-α, CCL2 and CCL3 genes. Statistical analyses examined differences in inflammatory markers and predictive modelling for diseased endometrium. RESULTS: Secreted concentrations of IFN-γ were lower in LVL fluid from reproductively healthy mares compared with acute endometritis (p = 0.04) and CEF (p = 0.006). Additionally, IL-17, IL-10, IL-1ß, TNF-α, CCL2, CCL3, CCL5 and CCL11 were significantly increased (p ≤ 0.04) in LVL from CEF mares compared with healthy mares. Mares with CCL2 concentrations ≥550 pg/mL (14/14) had 100% probability of having CEF and/or acute endometritis. Healthy mares had lower relative abundance of IL-17 mRNA compared with mares in CEF group [median (interquartile rage) = 14.76 (13.3, 15.3) and 12.4 (10.54, 13.81)], respectively (p = 0.02). MAIN LIMITATIONS: Limited sample size: larger numbers of mares with and without endometritis are required and reference intervals in LVL samples have to be established. CONCLUSIONS: Inflammatory chemokines and cytokines concentrations differed between healthy mares and mares with acute endometritis or CEF in LVL.

Ice formation and its elimination in cryopreservation of oocytes.

Damage from ice and potential toxicity of ice-inhibiting cryoprotective agents (CPAs) are key issues in assisted reproduction of humans, domestic and research animals, and endangered species using cryopreserved oocytes and embryos. The nature of ice formed in bovine oocytes (similar in size to oocytes of humans and most other mammals) after rapid cooling and during rapid warming were examined using synchrotron-based time-resolved x-ray diffraction. Using cooling rates, warming rates and CPA concentrations of current practice, oocytes show no ice after cooling but always develop large ice fractions - consistent with crystallization of most free water - during warming, so most ice-related damage must occur during warming. The detailed behavior of ice at warming depended on the nature of ice formed during cooling. Increasing cooling rates allows oocytes soaked as in current practice to remain essentially ice free during both cooling and warming. Much larger convective warming rates are demonstrated and will allow routine ice-free cryopreservation with smaller CPA concentrations. These results clarify the roles of cooling, warming, and CPA concentration in generating ice in oocytes and establish the structure and grain size of ice formed. Ice formation can be eliminated as a factor affecting post-thaw oocyte viability and development in many species, improving outcomes and allowing other deleterious effects of the cryopreservation cycle to be independently studied.

Faster sperm selected by rheotaxis leads to superior early embryonic development in vitro.

To understand the impact of sperm speed as they swim against the flow on fertilization rates, we created conditions similar to the female reproductive tract (FRT) on a microfluidic platform for sperm selection. Selected sperm were evaluated based on early development of fertilized embryos. Bovine and human spermatozoa were selected at various fluid flow rates within the device. We found that the speed of bovine spermatozoa increases as the flow rate increases and that the amount of DNA fragmentation index is lowered by increasing the flow rate. Bovine spermatozoa selected by our platform at low (150 µL h-1, shear rate 3 s-1), medium (250 µL h-1, shear rate 5 s-1), and high flow rates (350 µL h-1, shear rate 7 s-1) were used for fertilization and compared to sperm sorted by centrifugation. The samples collected at the highest flow rate resulted in the formation of 23% more blastocysts compared to the control. While selecting for higher quality sperm by increasing the flow rate does result in lower sperm yield, quality improvement and yield may be balanced by better embryonic development.

The evolution of centriole degradation in mouse sperm.

Centrioles are subcellular organelles found at the cilia base with an evolutionarily conserved structure and a shock absorber-like function. In sperm, centrioles are found at the flagellum base and are essential for embryo development in basal animals. Yet, sperm centrioles have evolved diverse forms, sometimes acting like a transmission system, as in cattle, and sometimes becoming dispensable, as in house mice. How the essential sperm centriole evolved to become dispensable in some organisms is unclear. Here, we test the hypothesis that this transition occurred through a cascade of evolutionary changes to the proteins, structure, and function of sperm centrioles and was possibly driven by sperm competition. We found that the final steps in this cascade are associated with a change in the primary structure of the centriolar inner scaffold protein FAM161A in rodents. This information provides the first insight into the molecular mechanisms and adaptive evolution underlying a major evolutionary transition within the internal structure of the mammalian sperm neck.

Characterization and cryopreservation of semen from endangered markhor goats (Capra falconeri heptneri) with evaluation of reproductive seasonality.

The aims of this study were to determine the reproductive seasonality of four captive markhor goats (Capra falconeri heptneri), to characterize semen collected by electroejaculation, and to compare extenders and processing techniques for semen cryopreservation. Over the course of 1 yr, mean monthly scrotal circumference, serum testosterone, and fecal testosterone were measured and found to be inversely associated with day length. Maximum scrotal circumference (25.2 +/- 0.9 cm), serum testosterone (521.0 +/- 103.4 ng/dl), and fecal testosterone (382.5 +/- 90.3 ng/g) occurred in November, when day length was short (9.7 +/- 0.1 hr). Once a month for 3 mo (December, January, and February), bucks were anesthetized for electroejaculation and semen evaluation. Semen samples were divided into six aliquots for extension and cryopreservation in soy-based Bioxcell or Tris-based extender with 5 or 15% egg yolk, with and without centrifugation. Samples were then thawed for repeat evaluation 1-3 mo later. Postthaw evaluation revealed no significant differences between centrifuged and noncentrifuged samples. Sperm in Tris 5% and 15% egg yolk displayed higher total motility at 0, 3, and 6 hr postthaw and higher progressive motility postthaw compared with sperm in Bioxcell (P < 0.05). Sperm in Bioxcell displayed higher viability than sperm in both Tris-egg yolk extenders (P < 0.01), more intact acrosomes than sperm in Tris-15% egg yolk (P < 0.05), and a tendency for more intact acrosomes than sperm in Tris-5% egg yolk (P < 0.10). Sperm in Tris-5% egg yolk tended to have a higher percentage of morphologically normal sperm compared with Bioxcell (P < 0.10). This study provides evidence that markhor goats exhibit seasonality in scrotal circumference and testosterone levels and that centrifugation may be eliminated from the processing of markhor semen.

Transient increases in glutamate dehydrogenase (GLDH) activity occur in neonatal foals.

BACKGROUND: Liver analyte measurement is important in the evaluation of sick animals. Liver injury in horses is recognized by increased glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), and aspartate aminotransferase (AST) activities, whereas biliary pathology is identified by increased alkaline phosphatase and γ-glutamyl transferase (GGT) activities or bilirubin concentrations. We have observed high GLDH, but not SDH, activities in neonatal foals admitted for conditions other than liver disease. Only one previous study have evaluated GLDH activity over time in healthy neonatal foals; however, SDH activity was not measured. OBJECTIVE: We aimed to evaluate changes in liver analytes in neonatal foals over time. METHODS: We measured serum liver analytes (GLDH, SDH, GGT, AST, total, direct, and indirect bilirubin) and creatine kinase activity of 11 clinically healthy foals before and at various times after suckling until 46 days of age. Analytes were also measured in colostrum and mare serum. RESULTS: Median GLDH activities increased after birth to peak at 3-4 days of age (106 U/L, reference interval, 0-8 U/L). Median SDH activities had a lower peak at 3-4 days (15 U/L, reference interval, 0-11 U/L) and were frequently discordant with GLDH. There was no association between foal and mare serum or colostral enzyme activities. AST activity plateaued at 5-6 days, whereas GGT activity and total and indirect bilirubin concentrations peaked at 14 and 3-4 days of age, respectively. CONCLUSIONS: Transient increases in GLDH, SDH, and GGT activities and total and indirect bilirubin concentrations occur in clinically healthy neonatal foals and do not necessarily indicate relevant liver disease.