Hormone-responsive organoids from domestic mare and endangered Przewalski's horse endometrium.

The endometrium, the inner uterine lining, is composed of cell layers that come in direct contact with an embryo during early pregnancy and later with the fetal placenta. The endometrium is responsible for signals associated with normal reproductive cyclicity as well as maintenance of pregnancy. In the mare, functionally competent in vitro models of the endometrium have not been successful. Furthermore, the ability to study various reproductive processes in vitro may allow critical evaluation of signaling pathways involved in the reproductive diseases of animals that cannot be handled frequently, such as various wildlife species. Here we report the establishment of organoids, 3D structures, derived from fresh and frozen-thawed equine endometrium (Equus ferus caballus and E. f. przewalskii). Although organoids from domestic mares responded to exogenous hormonal stimuli, organoids from Przewalski's horse failed to respond to exogenous hormones. The present study represents a 'first' for any large animal model or endangered species. These physiologically functional organoids may facilitate improved understanding of normal reproductive mechanisms, uterine pathologies, and signaling mechanisms between the conceptus and endometrium and may lead to the development of novel bioassays for drug discovery.

A review of in vivo and in vitro studies of the mare endometrium.

The inner layer of the uterus, the endometrium, is responsible and necessary for many reproductive functions. Normal reproductive cyclicity, maternal recognition of pregnancy, maternal interaction with the embryo, and interaction of the reproductive tract with pathogens are dependent on the endometrium. Although most studies have been conducted in vivo using live animals, recent advances in in vitro approaches could facilitate future research in a laboratory setting with minimal effect on animals. Many reproductive studies have been performed in vivo and in vitro in equids, but new in vitro methods to study the endometrium of mares remain unexplored. In this review, there is a description of the normal anatomy and physiology of the mare endometrium in vivo, in vitro endometrial cell culture techniques that have been previously described for the mare, and opportunities for future reproductive research using in vitro methods.

Effect of oral meloxicam administration on growth performance and behavior of pre-weaning age calves following band castration.

The objective of this study was to determine if oral meloxicam (M; a nonsteroidal anti-inflammatory drug) administered at castration to pre-weaning age calves affected average daily gain (ADG) or behavior. Prior to castration (d -14), Angus bulls were weighed and randomly assigned to be band castrated (BAN; n = 8; age = 90.2 ± 6.5 d; BW = 146.3 ± 11.4 kg; scrotal circumference = 16.0 ± 0.5 cm) or castrated with M (BAN + M; n = 9; age = 102.1 ± 6.2 d; BW = 146.0 ± 7.7 kg; scrotal circumference = 16.1 ± 0.3 cm). Six bulls selected to remain bulls based on pedigree and phenotype were maintained in the same pasture (BULL; age = 104.2 ± 6.1 d; BW = 172.1 ± 8.7 kg; scrotal circumference = 17.5 ± 0.4 cm). On d 0, BAN and BAN + M had a rubber band applied tightly around the scrotum, and BAN + M also received oral M (2 mg/kg BW). On d 1, 14, and 28, animals were weighed and a blood sample was collected to determine circulating concentrations of haptoglobin and fibrinogen. Data loggers were affixed to the legs of calves immediately prior to castration (d 0) to record behaviors [mean lying time (h/d), mean lying bouts (n/d), and steps (n/d)] at 1-min intervals and removed on d 28. Behavior and plasma data were tested for effect of treatment, day, and treatment × day interaction, and ADG data were tested for effect of treatment, period (d -14 to 1, d 1 to 14, and d 14 to 28), and treatment × period interaction using JMP procedures for repeated measures (SAS Inst. Inc., Cary, NC). BULL in period d 0 to 14 had greater ADG than all other treatment period combinations, and BULL had greater ADG than BAN or BAN + M overall (P < 0.05). There was no effect of M treatment on circulating concentrations of fibrinogen or haptoglobin (P > 0.05). On d 7 and 15, BAN took more steps than BAN + M (P < 0.05). BAN + M had more lying bouts than BAN on d 13 and 14 (P < 0.05). Overall, M administration had no effect on ADG post-castration and only had minor impacts on behavior in calves band castrated pre-weaning.

Persian onager (Equus hemionus onager) endometrial explant cryopreservation and in vitro culture.

Assisted reproduction of endangered equids, such as Persian onagers (Equus hemionus onager), is vital for species conservation. Little is known about Persian onager reproductive functions, including functions of the uterine endometrium. Recently, successful cryopreservation of the domestic mare endometrium was reported, but there is no information on cryo-sensitivity or in vitro culture of endometrial tissues of any non-domestic equid. In the present study, endometrial explants from Persian onagers were cryopreserved and cultured in vitro for 5 days. There was no difference between endometrial explants when 10% and 20% dimethyl sulfoxide (DMSO) was used for cryopreservation. Cell viability and structural integrity were comparable to fresh tissue. Abundance of estrogen receptor-α (ESR1) and progesterone receptor (PGR) mRNA transcript in endometrial explants was less in most treatment groups compared to the fresh tissue control. There was variation in E-cadherin mRNA abundance in endometrial explants among treatment groups with some treatment groups having a lesser abundance compared to the control group. The abundance of Ki67 mRNA transcript of endometrial explants was not different among treatment groups compared to the control group. Results indicate that DMSO is a suitable cryoprotectant for the Persian onager endometrium, and in vitro culture in a liquid-gas interface can maintain Persian onager endometrial explants for as long as 5 days. Findings allow for a greater understanding of reproductive mechanisms in vitro for this endangered species and other domestic equids including donkeys.

Trimming and Re-shoeing Results in More Steps per Day and More Time Spent Lying per Day.

To examine the impact of trimming and re-shoeing on behavior, light horse geldings (3-21 year-old Quarter Horse, Dutch Warmblood, or Thoroughbred) were fitted with three-axis accelerometers (IceTag, Ice Robotics, Edinburgh, Scotland) on the left rear limb. Boots were placed under the accelerometer, and both were removed daily for approximately 1 hour while horses were stalled for morning feeding to examine the horses' limb. After a two-day adaptation period and five days of activity tracking, horses were treated by having shoes removed, feet trimmed, and new shoes fitted (re-shod; n = 3) or being handled but not trimmed or fitted with new shoes (sham; n = 4). Horse activity was monitored for five days after treatment. Steps per day, time spent lying per day, and the number of lying bouts were tested for effects of treatment, time (before or after treatment), and interaction of treatment by time using procedures for repeated measures with JMP Software (version 7, SAS Inst. Inc, Cary, NC). Means separation was performed using the Student's t-test. There was a treatment by time interaction on time spent lying per day (P = .0447) and steps per day (P = .0501). Re-shod spent more time lying after treatment than before (121.4 ± 22.8 vs 66.8 ± 22.8 minutes per day, respectively). After treatment, re-shod also took more steps than sham (3499 ± 527 vs 3056 ± 456 steps per day, respectively). These results may indicate increased mental and physical comfort following trimming and re-shoeing in horses.

Uterine Torsion Dystocia Complicated by Perosomus Elumbis in an Angus Calf Associated with a Consanguineous Mating.

A six-year-old multiparous Angus cow was presented for dystocia. Vaginal and rectal examinations revealed an approximately 360° counterclockwise uterine torsion. The torsion was corrected by rolling the cow counterclockwise (three episodes) with the aid of a plank coupled with manual detorsion via the vagina. The placement of obstetric chains followed by manual traction ultimately delivered a stillborn male calf with evidence of vertebral aplasia, arthrogryposis, and abdominal organ herniation. Patient history and subsequent parentage verification revealed that the calf was the result of a consanguineous (mother to son) mating. Tissue samples from the affected calf and blood samples from the dam, sire, and ten half siblings were collected for genetic testing and parentage verification. Necropsy, radiographic, and computed tomography examinations all supported a diagnosis of perosomus elumbis. Perosomus elumbis is a congenital abnormality of unknown origin(s), and this is the first report of a case associated with a consanguineous mating.

Intravenous infusion of kisspeptin increased serum luteinizing hormone acutely and decreased serum follicle stimulating hormone chronically in prepubertal bull calves.

Kisspeptin (KP) is a hypothalamic neuropeptide that stimulates the secretion of gonadotropin releasing hormone. To determine the acute and chronic effects of KP on serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH), prepubertal bull calves [12 ± 1 (SD) weeks of age; 96.5 ± 14.5 kg BW] were administered one of four treatments [0.0 (control; CON), 0.125 (L-KP), 0.25 (M-KP), or 0.5 (H-KP) µg of KP/kg BW/hour] by intravenous infusion for 76 h. Blood samples were collected every 15 min for the first (acute; 1-6 h; Day 1) and last (chronic; 71-76 h; Day 4) 6 h of the intravenous infusions. Serum concentrations of LH and FSH were determined by radioimmunoassay. For each day, effects of treatment, time, and interactions on LH and FSH concentrations and pulse parameters were analyzed using procedures for repeated measures with JMP Software (SAS Inst. Inc., Cary, NC). There was a treatment effect (P = 0.002) and a treatment × time interaction during Day 1 (P = 0.02) such that LH concentrations were greatest following administration of all doses of KP when compared to CON. However, there was no treatment effect (P = 0.57) or a treatment × time interaction during Day 4 (P = 0.20) on serum LH concentrations. There was a treatment by day interaction (P = 0.02) on mean serum FSH concentrations. Most notably, on Day 4 mean serum FSH concentrations during intravenous infusion of M-KP and H-KP doses were less than that of CON. There was a treatment by day interaction (P = 0.0054) on FSH pulse amplitude concentrations, such that intravenous infusion of all doses of KP on Day 4 decreased FSH pulse amplitudes. In conclusion, acute infusion of KP increased LH concentrations and chronic infusion of KP decreased FSH concentrations. Despite the potential suppression of the hypothalamic-pituitary-gonadal axis with chronic infusion of KP, there are likely applications of KP, KP analogs, or KP receptor agonists to hasten the onset of puberty in livestock.

Tarsocrural joint polymyxin B concentrations achieved following intravenous regional limb perfusion of the drug via a saphenous vein to healthy standing horses.

OBJECTIVE: To determine whether therapeutic concentrations (> 0.5 to 1.0 µg/mL) of polymyxin B (PB) were achieved in the tarsocrural joint of horses when the drug was administered by IV regional limb perfusion (IV-RLP) via a saphenous vein at doses of 25, 50, and 300 mg and to describe any adverse systemic or local effects associated with such administration. ANIMALS: 9 healthy adult horses. PROCEDURES: In the first of 2 experiments, 6 horses each received 25 and 50 mg of PB by IV-RLP via a saphenous vein with at least 2 weeks between treatments. For each treatment, a tourniquet was placed at the midmetatarsus and another was placed midway between the stifle joint and tarsus. Both tourniquets were removed 30 minutes after the assigned dose was administered. Blood and tarsocrural joint fluid samples were collected for determination of PB concentration before and at predetermined times after drug administration. In experiment 2, 4 horses were administered 300 mg of PB by IV-RLP in 1 randomly selected pelvic limb in a manner identical to that used in experiment 1. RESULTS: For all 3 doses, the mean synovial fluid PB concentration was > 10 times the therapeutic concentration and below the level of quantification at 30 and 1,440 minutes after drug administration, respectively. No adverse systemic or local effects were observed following PB administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that IV-RLP of PB might be a viable alternative for treatment of horses with synovial infections caused by gram-negative bacteria.

Effects of central and peripheral administration of an acute-phase protein, α-1-acid-glycoprotein, on feed intake and rectal temperature in sheep.

In rodents, an acute-phase protein, α-1-acid-glycoprotein (AGP), was shown to provide a link between inflammation and suppression of feed intake by acting as a leptin receptor agonist. The objective of this study was to determine the effects of AGP on feed intake and rectal temperature in sheep. Ewes were ovariectomized, implanted with a cannula into a lateral ventricle of the brain, and kept indoors in individual pens. Feed intake and rectal temperature were determined for sheep in all experiments. In the first experiment, ewes (n = 4) received 1 of 4 treatments [0 (control), 0.012 (low), 0.06 (medium), or 0.30 (high) mg/kg BW AGP] into the lateral ventricle (ICV). All sheep received all treatments in a Latin square design balanced for carryover effects with 10 d between treatments. In the second experiment, ewes (n = 10) received 1 of 2 treatments (0 and 3 mg/kg BW of AGP) intravenously (IV) in a completely randomized design. In the third experiment, ewes (n = 19) received peripheral treatments (IV) of an antipyretic [0 (control) or 2.2 mg/kg BW flunixin meglumine (FLU)] 30 min before receiving central AGP [0 (control) or 0.3 mg/kg BW of AGP] in a completely randomized design. All data were analyzed using a mixed model analysis of variance and tested for effects of treatment, time, and the interaction of treatment and time. Cumulative 48-h feed intake after administration of treatments was also determined. In the first experiment, there was no effect of ICV treatment (P = 0.37) on feed intake rate or on cumulative feed intake (P = 0.31). There was an effect of ICV treatment (P = 0.002) on rectal temperatures, which were greater (P < 0.05) after the high dose of centrally administered AGP. In the second experiment, there was no effect of AGP administration IV on feed intake rate (P = 0.98), on cumulative feed intake (P = 0.41) or on rectal temperature (P = 0.71). In the third experiment, there was an effect of central AGP treatment (P < 0.0001) and an interaction of central AGP and time (P < 0.0001) on rectal temperature, whereas FLU had no effect (P = 0.93), demonstrating that AGP increased rectal temperatures regardless of antipyretic treatment. These results indicate that central AGP increases rectal temperature in sheep by pathways that do not involve prostaglandins. Further research is needed to determine whether AGP may be an important integrator of energy balance and inflammation.

Dimethyl sulfoxide maintains structure and function of cryopreserved equine endometrial explants.

Availability of viable frozen-thawed endometrial tissues could facilitate detailed studies into physiologic and disease processes influencing the endometrium. This study was designed to investigate the cryosurvival of equine endometrial tissue. Previous studies in the human and horse have focused on cryopreservation of dissociated endometrial cells. To our knowledge, there are no studies on cryopreservation of endometrial explants. Our objectives were to 1) determine the influence of differing concentrations of the permeating cryoprotectant dimethyl sulfoxide (Me2SO) on viability, structural integrity, and gene expression of cryopreserved equine endometrial tissues prior to and following a 5-day explant culture in vitro and 2) examine the influence of low (1000 mg/L dextrose) vs high (4500 mg/L dextrose) glucose medium during in vitro culture. Both 10% and 20% (v/v) concentrations of Me2SO maintained viability following cryopreservation and in vitro culture. In addition, gene expression remained unaltered following cryopreservation with either 10% or 20% Me2SO. However, tissue structural integrity was slightly reduced compared to the fresh control. Furthermore, there was no difference in structural integrity, cell viability, or gene expression between low and high glucose medium during in vitro culture. Although E-cadherin and Ki67 gene expression was not different among fresh, 10% Me2SO, and 20% Me2SO treatments prior to or following tissue culture, estrogen receptor-α and progesterone receptor gene expression were reduced in all groups after explant culture. This is the first report of successful cryopreservation of equine endometrial explants.

Factors associated with seroprevalence of bovine anaplasmosis in Mississippi, USA.

Anecdotally, Veterinary Feed Directive prescriptions in the southeastern United States (U.S.) are written most often for treatment and prevention of bovine anaplasmosis (BA) but seroprevalence estimates and factors associated with this disease are currently unavailable in Mississippi (MS). Bovine anaplasmosis, a tick-borne disease of cattle caused by Anaplasma marginale, remains an economically important disease in U.S. The lack of recent seroprevalence of BA throughout the U.S. makes accurate assessment of production losses incurred by the cattle industry in the U.S. difficult, if not impossible to estimate. This study was aimed at determining the seroprevalence of and factors associated with BA in MS. Data were obtained from an active survey of 207 beef cows slaughtered between May 2013 and December, 2014 as well as from reviewing 5182 Veterinary Diagnostic Laboratories (VDLs) records of specimens from MS submitted for BA testing between 2002 and 2018. From the active surveillance, the overall observed apparent seroprevalence of BA in MS with cELISA was 28.99% (95% CI: 23.23 - 35.50%) while the estimated true seroprevalence was 29.02% (22.74 - 36.07%). However, from the laboratory records, the overall apparent period seroprevalence of BA in MS between 2002 and 2018 irrespective of diagnostic assay used was 16.72% (15.73 - 17.76%) and yearly increase in the diagnosis of BA followed a significant trend (P < 0.0001). With cELISA, the apparent seroprevalence of BA was 22.11% (20.78 - 23.49%) and the estimated true seroprevalence was 21.62% (20.18 - 23.11%). However, with CFT, the apparent seroprevalence of BA was 13.50% (10.75 - 16.81%) and the estimated true seroprevalence was 47.90% (36.30 - 61.87%). Factors associated with positive BA results were age, cattle type, and quarter of the year the specimens were submitted. The odds of the outcome were 22 as high in adults, 27 times as high in beef cattle, and 2 times as high between October to December in comparisons to juveniles, dairy cattle, and between April to June, respectively. Cattle population in the counties was not associated with positive BA results. Current records from the VDLs appear to accurately estimate the seroprevalence of BA in MS and thus serves as a reliable surveillance tool BA in the state. Because the burden of BA appears to be distributed throughout the state, future prevention and control measures for BA should focus on the identified putative risk factors and be intensified throughout MS.

Seroprevalence of bovine Anaplasmosis in Georgia.

Anecdotally, Veterinary Feed Directive prescriptions in many states in the southeastern United States (U.S.) are written most often for treatment and prevention of bovine anaplasmosis (BA). This tick-borne disease of cattle caused by Anaplasma marginale remains an economically important disease in U.S. However, there are no prevalence estimates of this disease in Georgia (GA). Thus, this study was aimed at determining the seroprevalence of BA in GA. In an active cull beef cow screening for BA, 293 beef cows were sampled from one cattle auction barn and one slaughterhouse between May 2013 and September 2014. These cows originated from 6 of 159 counties in GA. The top 3 counties sampled were Gordon (241 samples), Carroll (25 samples), and Emanuel (12 samples). Of the 293 sampled beef cows, 13 were positive and 280 were negative for BA. Hence, with competitive ELISA, the overall observed apparent seroprevalence of BA in GA was 4.44% (95% CI: 2.61-7.44%) while the estimated true seroprevalence was 2.62% (95% CI: 5.2-5.87%). The top 2 prevalent counties were Carroll and Gordon with apparent seroprevalence of 8% (95% CI: 2.22-24.97) and 4.78% (95% CI: 2.69-8.36), respectively and estimated true seroprevalence of 6.45% (95% CI: 0-25.37) and 2.99% (95% CI: 0.54-6.89), respectively. Although not significant, counties with specimen submissions for BA testing had a greater cattle population and number of cattle farms than counties without specimen submissions. Nevertheless, future prevention and control measures for BA should out of caution target counties with ≥5000 total cattle heads.

Beta-hydroxybutyrate infusion identifies acutely differentially expressed genes related to metabolism and reproduction in the hypothalamus and pituitary of castrated male sheep.

To identify molecular pathways that couple metabolic imbalances and reproduction, we randomly assigned 10 castrated male sheep to be centrally injected into the lateral ventricle through intracerebroventricular cannulas with 1 ml of ß-hydroxybutyric acid sodium salt solution (BHB; 12,800 µmol/l) or saline solution (CON; 0.9% NaCl). Approximately 2 h postinjection, sheep were humanely euthanized, and hypothalamus and pituitary tissues were harvested for transcriptome characterization by RNA sequencing. RNA was extracted from the hypothalamus and pituitary and sequenced at a high depth (hypothalamus: 468,912,732 reads; pituitary: 515,106,092 reads) with the Illumina Hi-Seq 2500 platform and aligned to Bos taurus and Ovis aries genomes. Of the total raw reads, 87% (hypothalamus) and 90.5% (pituitary) mapped to the reference O. aries genome. Within these read sets, ~56% in hypothalamus and 69% in pituitary mapped to either known or putative protein coding genes. Fragments per kilobase of transcripts per million normalized counts were averaged and ranked to identify the transcript expression level. Gene Ontology analysis (DAVID Bioinformatics Resources) was utilized to identify biological process functions related to genes shared between tissues, as well as functional categories with tissue-specific enrichment. Between CON- and BHB-treated sheep, 11 and 44 genes were differentially expressed (adj. P < 0.05) within the pituitary and hypothalamus, respectively. Functional enrichment analyses revealed BHB altered expression of genes in pathways related to stimulus perception, inflammation, and cell cycle control. The set of genes altered by BHB creates a foundation from which to identify the signaling pathways that impact reproduction during metabolic imbalances.

Factors associated with seroprevalence of bovine anaplasmosis in Texas.

Bovine anaplasmosis (BA), caused by Anaplasma marginale, is an economically important tick-borne disease of cattle in the United States (U.S.) and worldwide. Anecdotally, Veterinary Feed Directive prescriptions in the southeastern U.S. are written mostly for treatment/prevention of BA. However, there are no recent temporal seroprevalence estimates of BA in Texas (TX). Thus, this study was aimed at determining the seroprevalence of and factors associated with BA in TX. Data were obtained from an active slaughter survey (n = 215) performed between August and December 2014 as well as from reviewing Texas A&M Veterinary Medical Diagnostic Laboratories (TVMDLs) records of specimens submitted for BA testing from January 2002 to June 2012 (n = 15,460). Irrespective of the assay used, the overall apparent seroprevalence of BA in TX between 2002 and 2012 was 15.91% (95% CI: 15.34 - 16.50%) and the yearly increase in seroprevalence followed a significant trend (P < .0001). With cELISA, the apparent seroprevalence of BA was 13.49% (95% CI: 9.56 - 18.7%) and 13.02% (95% CI: 9.74 - 17.18%) for the slaughter survey and TVMDLs records between October and December 2011, respectively. Whereas the estimated true seroprevalence for the same period was 12.35% (95% CI: 8.04 - 18.05%) and 12.78% (95% CI: 9.19 - 17.30%), respectively. Factors associated with positive BA results were age, breed, diagnostic assay used, year and quarter of the year the specimens were submitted. The odds of the outcome were 1.5 times as high when cattle were adults (vs juvenile). In comparison to other breeds, the odds of the outcome were 11.57, 7.16, and 2.5 times higher in Hereford, Angus, and mixed breeds, respectively. When compared to 2003, the odds of the diagnosis of BA was approximately 2 times as high in 2010 but 3 times as high in 2002, 2005, and 2011 and approximately 4 times as high in 2006 and 2007. In comparison to the duration from October to December, the odds of the outcome were approximately 1.5 as high from January to March and from July to September durations. Counties with specimen submissions for BA testing had a significantly greater cattle population (p = .0061) and number of cattle farms (p < .001) than counties without specimen submissions. Subsequent prevention and control measures for BA should target these factors and should prioritize on counties with higher cattle population in the eastern part of TX. Furthermore, TVMDLs records appear sufficient for the surveillance of BA in TX.

Factors associated with Seroprevalence of Anaplasma marginale in Kentucky cattle.

Bovine anaplasmosis (BA) is tick-borne disease of cattle caused by Anaplasma marginale and it remains an economically important disease in the United States (U.S.). We have anecdotal information that Veterinary Feed Directive prescriptions in Kentucky (KY) are written most often for treatment and prevention of BA. However, there are no recent prevalence estimates of this disease in KY. Thus, this study was aimed at determining the seroprevalence of and factors associated with BA in KY. Data were obtained from an active slaughter survey (n = 232) performed between May and July 2013 as well as from reviewing The University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) records of specimens submitted for BA testing from 2002-2012 (n = 2,573). With competitive ELISA, the apparent prevalence of BA in KY was 10.78% (95% CI: 7.41-15.42%) and 11.58% (95% CI: 10.31-12.98%) for the slaughter survey and laboratory records, respectively. Whereas the estimated true prevalence was 9.44% (95% CI: 5.65-14.48%) and 10.3% (95% CI: 8.92-11.8%), respectively. From the laboratory records, factors associated with positive BA results were age, breed, whether specimens were submitted singularly or as a group, year and quarter of the year the specimens were submitted. The odds of the outcome were 5 times as high when cattle were adults (vs juvenile) and almost 4 times as high when specimens were submitted singularly (vs group). In comparison to Holstein breed, the odds of the outcome were 3.5 and 2.5 times higher in Angus and mixed breeds, respectively. The odds of a diagnosis of BA varied in an undulating pattern by year of sample submission. When compared to 2011, the odds of a diagnosis of BA was approximately 3 times as high in 2005, 2008, and 2009 and approximately 5 times as high in 2004, 2006, and 2012. In comparison to the duration from January to March, the odds of the outcome were almost 20 times as high from July to September but 10 times as high from October to December durations. Counties with specimen submissions for BA testing had a significantly greater cattle population and number of cattle farms than counties without specimen submissions. Future prevention and control measures for BA should target these factors and should be weighted more on counties with higher cattle population. Furthermore, current records from the UKVDL appear sufficient for the surveillance of BA in KY.

Adeno-Associated Virus Gene Therapy in a Sheep Model of Tay-Sachs Disease.

Tay-Sachs disease (TSD) is a fatal neurodegenerative disorder caused by a deficiency of the enzyme hexosaminidase A (HexA). TSD also occurs in sheep, the only experimental model of TSD that has clinical signs of disease. The natural history of sheep TSD was characterized using serial neurological evaluations, 7 Tesla magnetic resonance imaging, echocardiograms, electrodiagnostics, and cerebrospinal fluid biomarkers. Intracranial gene therapy was also tested using AAVrh8 monocistronic vectors encoding the α-subunit of Hex (TSD α) or a mixture of two vectors encoding both the α and ß subunits separately (TSD α + ß) injected at high (1.3 × 1013 vector genomes) or low (4.2 × 1012 vector genomes) dose. Delay of symptom onset and/or reduction of acquired symptoms were noted in all adeno-associated virus-treated sheep. Postmortem evaluation showed superior HexA and vector genome distribution in the brain of TSD α + ß sheep compared to TSD α sheep, but spinal cord distribution was low in all groups. Isozyme analysis showed superior HexA formation after treatment with both vectors (TSD α + ß), and ganglioside clearance was most widespread in the TSD α + ß high-dose sheep. Microglial activation and proliferation in TSD sheep-most prominent in the cerebrum-were attenuated after gene therapy. This report demonstrates therapeutic efficacy for TSD in the sheep brain, which is on the same order of magnitude as a child's brain.

Effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses for a five-day period on behavioral and biochemical indicators of pain, stress, and inflammation.

OBJECTIVE To determine the effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses on behavioral and biochemical indicators of pain, stress, and inflamation. ANIMALS 20 Tennessee Walking Horses. PROCEDURES Horses were randomly assigned to 2 treatment groups: keg shoes (control; n = 10) or stacked wedge pads and exercise with chains (10). Ten days before treatment application, an accelerometer was attached at the left metatarsus of each horse to record daily activity. Horses were exercised for 20 minutes daily, beginning on day -7. On day 0, exercise ceased, the forefeet were trimmed, and the assigned treatment was applied. From days 1 through 5, horses were exercised as before. Blood samples for measurement of plasma cortisol, substance P, and fibrinogen concentrations were collected on days -5, 1, and 5 before and after exercise and every 30 minutes thereafter for 6 hours. RESULTS No significant differences in plasma concentrations of cortisol, substance P, and fibrinogen were detected between groups. Although lying behaviors changed after shoes were applied, these behaviors did not differ significantly between groups. Shoeing appeared to have altered behavior to a greater extent than did the type of treatment applied. CONCLUSIONS AND CLINICAL RELEVANCE Application of stacked wedge pads and chains to the forefeet of horses for a 5-day period as performed in this study evoked no acute or subacute stress or nociceptive response as measured. Although these findings should not be extrapolated to the long-term use of such devices in Tennessee Walking Horses performing the running walk, the data should be considered when making evidence-based decisions relating to animal welfare and the use of stacked wedge pads and chains.

Kisspeptin Stimulates Growth Hormone Release by Utilizing Neuropeptide Y Pathways and Is Dependent on the Presence of Ghrelin in the Ewe.

Although kisspeptin is the primary stimulator of gonadotropin-releasing hormone secretion and therefore the hypothalamic-pituitary-gonadal axis, recent findings suggest kisspeptin can also regulate additional neuroendocrine processes including release of growth hormone (GH). Here we show that central delivery of kisspeptin causes a robust rise in plasma GH in fasted but not fed sheep. Kisspeptin-induced GH secretion was similar in animals fasted for 24 hours and those fasted for 72 hours, suggesting that the factors involved in kisspeptin-induced GH secretion are responsive to loss of food availability and not the result of severe negative energy balance. Pretreatment with the neuropeptide Y (NPY) Y1 receptor antagonist, BIBO 3304, blocked the effects of kisspeptin-induced GH release, implicating NPY as an intermediary. Kisspeptin treatment induced c-Fos in NPY and GH-releasing hormone (GHRH) cells of the arcuate nucleus. The same kisspeptin treatment resulted in a reduction in c-Fos in somatostatin (SS) cells in the periventricular nucleus. Finally, blockade of systemic ghrelin release or antagonism of the ghrelin receptor eliminated or reduced the ability of kisspeptin to induce GH release, suggesting the presence of ghrelin is required for kisspeptin-induced GH release in fasted animals. Our findings support the hypothesis that during short-term fasting, systemic ghrelin concentrations and NPY expression in the arcuate nucleus rise. This permits kisspeptin activation of NPY cells. In turn, NPY stimulates GHRH cells and inhibits SS cells, resulting in GH release. We propose a mechanism by which kisspeptin conveys reproductive and hormone status onto the somatotropic axis, resulting in alterations in GH release.

Prevalence of Tritrichomonas foetus in tennessee bulls.

The prevalence of bovine trichomonosis (BT) in TN bulls was estimated through both active screening of bulls and review of previous laboratory records. During the active bull screening, preputial smegma specimens were collected from 458 TN beef bulls at 2 cattle slaughterhouses and 2 stockyards, which serve most beef bulls in TN, between March 2014 and June 2015. Each specimen was cultured for Tritrichomonas foetus (T. foetus) as well as evaluated microscopically every other day for seven days for any protozoa resembling T. foetus. An aliquot of the culture media from each specimen was used for DNA extraction and subsequent qPCR testing. Two specimens were considered suspect on microscopic evaluation, but all specimens were negative for T. foetus on qPCR. This suggests that the 2 specimens were most likely contaminated by fecal trichomonads. Retrospectively, 1979 T. foetus test records from 2 major TN diagnostic laboratories were reviewed between October 2013 and September 2016. True prevalence of BT in TN beef bulls was estimated at <0.01% from the laboratory records, although the county prevalence differed in 2 TN counties (Marshal: 0.09% and Bedford: 0.5%). Overall, the prevalence of BT in TN is low, and the current screening efforts to help control BT disease in TN are acceptable. Future efforts should focus on educating cattle stakeholders on the importance of optimal specimen collection and handling as well as routine testing for BT before cattle movement. In addition, cattle producers should be reminded of leading risk factors associated with BT in cattle.

Comparison of penetrating and nonpenetrating captive bolt methods in horned goats.

OBJECTIVE To use MRI and CT to compare the amount of tissue damage (soft tissue and bone) to the heads of goats after administration of a nonpenetrating or penetrating captive bolt. ANIMALS Cadavers of twelve 1- to 5-year-old mixed-breed goats that had been euthanized with an overdose of pentobarbital as part of an unrelated study. PROCEDURES Cadavers were randomly assigned to receive a nonpenetrating (n = 6) or penetrating (6) captive bolt. The head of 1 cadaver was imaged via CT and MRI. The muzzle of a device designed to administer either a penetrating or nonpenetrating captive bolt was then placed flush on the dorsal midline of each head at the level of the external occipital protuberance (poll) and aimed downward toward the cranialmost portion of the intermandibular space, and the assigned bolt was administered. Heads were removed, and CT and MRI of each head were performed. After imaging, each skull was transected along the sagittal plane to permit gross evaluation of central nervous tissue and obtain digital photographic images. In addition, 1 head that received a nonpenetrating captive bolt was further evaluated via blunt dissection and removal of adnexa from the external surface of the calvarium. RESULTS MRI, CT, and dissection of skulls revealed severe skeletal and soft tissue damage after impact with the penetrating and nonpenetrating captive bolts. CONCLUSIONS AND CLINICAL RELEVANCE The nonpenetrating captive bolt appeared to cause damage similar to that of the penetrating captive bolt in the cranium and soft tissues of the head in caprine cadavers. This damage suggested that administration of a nonpenetrating captive bolt as described here may be an acceptable method of euthanasia in goats.