Help Advance Neonatal Foal Care – Share Your Experience with the Madigan Squeeze Technique

(c) Pfluegler | Dreamstime.com

 Have you used the Madigan Squeeze Technique on neonatal foals? Dr. Monica Aleman and Dr John Madigan of UC Davis are inviting veterinarians, breeders, farm managers, and horse owners to share their experiences as part of a vital study aimed at improving outcomes for foals with Neonatal Maladjustment Syndrome (“dummy foal”).

Neonatal Maladjustment Syndrome (NMS) is a condition seen in newborn foals that affects their behaviour and awareness. Foals with NMS may not recognise or bond with their mother, may not suckle normally, and can seem disoriented. More seriously affected foals may develop seizures. NMS was once thought to be caused by lack of oxygen during birth, but recent research suggests it may also be linked to high levels of calming hormones (neurosteroids) that usually decrease after birth but sometimes remain too high.

 

The Madigan Squeeze Technique, developed by Dr. Madigan, involves applying steady pressure using soft ropes wrapped in 3–4 loops around the foal’s chest and rib cage for approximately 20 minutes. This mimics the natural birth process and is believed to reduce neurosteroid levels that keep foals in a subdued, sleep-like state in utero. The foal typically lies down and enters a calm, trance-like state, then awakens more alert—often with improved responsiveness.

 

Drs. Aleman and Madigan are collecting real-world data on the technique’s effectiveness and application. Whether you’ve experienced remarkable recoveries, faced challenges, or simply observed how the technique worked, your insights are essential.

 

“Your experiences - whether as a veterinarian, breeder, farm manager, or horse owner - are invaluable in helping us assess how widely the technique is used and how effective it has been,” they note.

 

By contributing, you'll help shape a forthcoming report on neonatal foal care that will be shared with the broader equine community - advancing research and potentially improving foal survival rates worldwide.

 

 

Take the survey here:

 

 https://www.surveymonkey.com/r/M3J2P32 

Updated HBLB Codes of practice now available

The Horserace Betting Levy Board (HBLB) Codes of Practice, first introduced in 1977, were developed in response to the growing threat of Contagious Equine Metritis (CEM) and the lack of standardised biosecurity measures in the equine industry. CEM outbreaks were causing significant reproductive issues in mares and financial losses for breeders. The introduction of the Codes aimed to establish uniform disease prevention and control protocols, helping to safeguard equine health and protect the breeding industry.

The HBLB Codes of Practice outline voluntary, yet highly recommended, guidelines designed to assist breeders and their veterinary surgeons in the prevention, management, and control of specific infectious diseases in all breeds of horses and ponies.

While the Codes were originally intended for breeding enterprises and stud farms, their value extends beyond this sector. They have become a comprehensive resource on infectious disease control, biosecurity, and equine health management, making them relevant to:

• Horse owners aiming to prevent disease outbreaks in their yards.
• Riders and trainers seeking to maintain healthy horses and implement sound biosecurity practices.
• Veterinarians using the Codes as a reference for best practices in disease diagnosis, treatment, and prevention.

Since their introduction, the HBLB Codes of Practice have been regularly updated and expanded to include recommendations for controlling other significant equine diseases, such as:

• Equine Herpesvirus (EHV) – which can cause respiratory disease, abortion, and neurological symptoms.
• Equine Influenza (EI) – a highly contagious respiratory infection that can spread rapidly.
• Strangles – a bacterial infection caused by Streptococcus equi, known for its painful abscesses and potential complications.
• Equine Viral Arteritis (EVA) and Equine Infectious Anaemia (EIA) – both serious infectious diseases that threaten equine health.

As a result, the Codes have evolved into an essential reference not only for breeding establishments but also for all equine professionals, owners, and riders, offering a wealth of practical information on biosecurity, vaccination, and disease management. They are an invaluable resource for anyone involved in equine care and management, providing evidence-based guidance on reducing the risk of infectious disease outbreaks and promoting the overall health and welfare of horses.

 

The HBLB Codes of Practice are freely available online and can be accessed at:

https://codes.hblb.org.uk

 

Enhancing welfare in horse breeding

(c) Zuzana Tillerová. Dreamstime.com

 Researchers at Hartpury University are working with the World Breeding Federation for Sport
Horses (WBFSH) on a research project to improve equine welfare in horse breeding.

WBFSH, which represents 86 studbooks across 36 countries, serves as the key link between sport horse breeding and international equestrian sport. As the only global federation of studbooks for sport horses, WBFSH collaborates closely with the Fédération Equestre Internationale (FEI) to support breeders and advance sport horse development.

This research aims to provide fact-based recommendations and achieve measurable improvements in the welfare of sport horses worldwide.

The project, led by Hartpury University’s Head of Research, Prof. Jane Williams, followed a three-stage approach, combining industry consultation with a review of existing research.

First, interviews with 17 WBFSH members identified key welfare concerns in horse breeding. Next, a systematic review of scientific literature explored breeding practices, conditions, and interventions affecting horse welfare. Finally, focus groups were held with industry experts and leading academics in equine welfare.

The interviews highlighted three main welfare areas across the breeding cycle: selection of breeding stock, management of breeding stock, and care of foals and young horses. The literature review revealed that existing research often fails to take a holistic view of horse welfare needs.

Prof. Williams commented: ​ “Our research has demonstrated that welfare in horse breeding practices is still under-researched. ​ Our systematic review of the existing literature has highlighted areas where further work is needed. ​ We also found that to translate our findings into improving horse welfare in practice, we need to support a strong implementation strategy that is accessible and achievable.”

She added: “​ We are grateful for the support from the WBFSH not only in funding this research project, but also in their unwavering commitment to ensuring its findings lead to real improvements in horse welfare worldwide.”

The next step is for WBFSH to work with its member studbooks to implement the project’s findings. This includes incorporating a welfare statement into its statutes and promoting the consideration of behaviour, health, and longevity in breeding strategies. WBFSH states that it will also continue working with industry partners to prioritise equine welfare and support breeders through clear communication, resources, and webinars.

Green alternatives in equine reproduction

 The overreliance on plastic materials in all areas of modern life, including veterinary practice, poses a significant environmental challenge due to the pollution it generates.

Artificial insemination, a common technique in equine breeding programs, is a good example of the widespread nature of plastics in veterinary work. The procedure typically relies on disposable plastic items, such as insemination catheters and semen straws, which are essential for the collection, storage, and transfer of genetic material. However, their single-use nature contributes heavily to plastic waste. 

As part of the search for sustainable solutions, Noelia González and colleagues conducted a study to explore sustainable alternatives to conventional plastic semen straws. The study evaluated various biodegradable materials, including bamboo, avocado, grass, paper, Kraft paper, wheat, and rice, focusing on their suitability for preserving refrigerated, extended equine semen.

Among the materials tested, bamboo and avocado emerged as the most promising options. Bamboo displayed strong structural integrity, making it a durable and reliable container, However, avocado-based straws were particularly effective in maintaining sperm quality parameters, such as motility and movement kinetics, without introducing contaminants.

The research team conducted detailed assessments of the straws’ structural integrity and their ability to preserve semen quality after 24 and 96 hours of refrigeration. Both bamboo and avocado straws performed within acceptable ranges, but avocado straws yielded superior results. Additionally, microbiological control tests confirmed the absence of bacterial growth in both straw types, further supporting their potential as safe alternatives to plastic.

The findings suggest that avocado-based straws could serve as a viable alternative to plastic straws in artificial insemination procedures, offering an environmentally friendly solution without compromising the success of reproductive practices.

 

For more details, see:

 

González N, Peñalosa A, de Blas I, Gil L. 

Sustainable Alternatives to the Reduction of Plastic Straws Used with Chilled Equine Semen. 

Animals. (2024); 14(23):3388. 

https://doi.org/10.3390/ani14233388

Navigating the Equine Breeding Season: Mares Webinar

Are you new to horse breeding or looking to expand your knowledge? Join the American Association of Equine Practitioners (AAEP) for a free, informative webinar on the equine breeding season.

The webinar is directed toward horse owners/managers either new to breeding horses or those with limited experience. It will cover the basics of reproductive biology of the horse, logistics of the breeding season and what to expect when breeding your mare. 

The presenter is Dr. Dale Kelley, board-certified reproduction specialist at Oklahoma State University, College of Veterinary Medicine.

 

Access is free, but registration is required.

 

Details:

• Date and time : 

 

(USA) Wednesday, Oct. 30, 8:00 p.m. ET

(UK) Thursday, Oct. 31, midnight (00:00) GMT

 

• To register go to:

https://aaep-org.zoom.us/webinar/register/WN_CHkvKjmpTlGOiPMbwhEtBA#/registration

 

• Submit questions in advance through the registration form.

 

If you miss the live event, a recording will be available.

Adverse effect of bute on assisted reproduction in mares

(c) Zuzana Tillerova Dreamstime.com

 Phenylbutazone (“bute”) may not be as harmless for breeding animals as previously thought.

 Recent research from the USA indicates that bute can interfere with oocyte maturation and development after fertilization when assisted reproduction techniques are used.

 

While Thoroughbred mares often start breeding young, many other mares only begin breeding after a long working life. Many of these mares retire from work or start breeding due to orthopaedic problems that limit their performance and require regular NSAID treatment.

 

Researchers at the Texas A&M School of Veterinary Medicine & Biomedical Sciences (VMBS) have found that phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID) commonly prescribed in horses, can affect a mare’s egg cells (oocytes), hindering their ability to mature into viable embryos, which is crucial for assisted reproduction.

 

The study, led by Dr Luisa Ramírez-Agámez and colleagues, looked at the effect of bute on the developmental competence of in vitro-matured equine oocytes subjected to Intracytoplasmic Sperm Injection (ICSI). Their findings are published in the journal Theriogenology.

 

In a press release, Ramírez-Agámez explained: “Mare’s oocytes need approximately 30 hours to mature in the laboratory once they have been collected before they can be fertilized. Then, we have to inject the eggs with sperm to induce fertilization, a process known as Intracytoplasmic Sperm Injection (ICSI).

 

“We discovered that phenylbutazone, commonly known as bute, can affect both the ability of a mare’s eggs to mature correctly when cultured and whether the fertilized eggs will develop into a viable embryo. In either of those cases, the eggs affected by bute cannot be used in assisted reproduction.”

 

In a preliminary study, the research team compared cumulus-oocyte-complexes (COCs) harvested from two mares treated with bute for 10 days before collection with those from four untreated mares. (The term "cumulus-oocyte complex" (COC) refers to an oocyte and the surrounding cumulus cells within the follicle. The cumulus cells are essential for the oocyte's development and maturation, providing nutrients and signals, and aiding in fertilization and embryo development.)

 

They found that oocyte in vitro maturation and blastocyst rates were lower in bute-treated mares compared to the control mares.

 

In the main experiment, nine healthy mares received a daily dose of bute (4.4 mg/kg, orally, once a day) for 10 days, while ten control mares received a placebo.

 

The researchers performed ultrasound-guided transvaginal oocyte aspiration (TVA) on days 3, 33, and 77 following the last dose of bute. The COCs recovered from both groups were matured in vitro and subjected to ICSI.

 

They observed that while the in vitro oocyte maturation rate was similar between the bute and control groups, oocyte recovery, cleavage, and blastocyst rates were significantly lower in the bute-treated group. However, these effects were short-lived, as by 33 and 77 days post-treatment, in vitro maturation, cleavage, and blastocyst rates were similar between the two groups.

 

“In a future study, we hope to determine an alternative to bute that supplies the same level of pain management but does not interfere with reproduction,” she added. “The good news is that bute’s effect on equine oocytes appears to wear off within a few weeks.

 

“We found that eggs collected three days after administration of bute were not able to produce embryos, but those collected at 33 days were successful. We hope to find a more exact answer in terms of how bute affects egg cell quality in a future study.”

 

 

For more details, see:

 

Ramírez-Agámez L, Hernández-Avilés C, Whitfield-Cargile CM, Coleman MC, Love CC. 

Treatment of mares with the non-steroidal anti-inflammatory drug (NSAID) phenylbutazone transiently affects in vitro maturation of equine oocytes and blastocyst development after Intracytoplasmic Sperm Injection (ICSI). 

Theriogenology (2024) 223:53-58.

https://doi.org/10.1016/j.theriogenology.2024.04.017

Lyophilized colostrum: a viable alternative for foals?

 Colostrum is essential for a foal to have a good start in life. The first milk produced by mammals
after giving birth, colostrum is rich in antibodies, growth factors, and nutrients essential for newborn development. Foals require good quality colostrum in the first hours of life to ensure an adequate transfer of passive immunity.

Stud farms often maintain a supply of high-quality colostrum by collecting and freezing some from donor mares.

However, individual mare owners have more limited options. Commercial products like dried colostrum powder, usually made from processed cow colostrum, can provide some level of IgG to foals, but are generally not considered equivalent to mare colostrum in terms of quality and effectiveness.

 

Further research and development of equine-specific colostrum products, including lyophilized (freeze-dried) mare colostrum, may offer better alternatives for ensuring foal health and immunity.

 

Research by Thatyane Carla de Lima and colleagues, in Brazil, compared the quality of equine colostrum after freezing and lyophilisation, evaluating IgG concentration (using Simple Radial Immunodiffusion, SRID, and Brix refractometry) and the physicochemical characteristics of equine colostrum post-freezing and lyophilization. A report of their work is published in the Journal of Equine Veterinary Science

 

Thirty-one pregnant Quarter Horse mares participated in the study. Colostrum collected from these mares was divided into two samples: one for freezing and one for lyophilization. 

 

The research team measured the IgG concentration of both frozen and lyophilized colostrum by SRID, (the reference standard test), and Brix refractometry (a technique widely used for estimating colostrum quality in cattle.)   

 

Additionally, they evaluated properties such as pH, total protein (TP), fat, lactose, salts, total solids (TS), and density. They also tested the effect of reconstitution on the lyophilized colostrum.

 

They found no significant differences (P > 0.05) in IgG, fat, lactose, salts, TS, density, and pH between colostrum samples before and after lyophilization. Lyophilization resulted in a minor reduction (6.55%) in IgG concentration as measured by SRID.

 

 However, they did find a significant difference in the average Brix score and total protein, indicating that lyophilization alters some colostrum characteristics.

 

The results suggest lyophilization as a viable method for mare colostrum conservation, to ensure foals receive the essential nutrients and antibodies for a healthy start. It offers practical benefits, including long-term storage without refrigeration and easy transportation.

 

The authors suggest that further research, such as in vivo studies to evaluate the product's acceptance and the absorption of immunoglobulins, is recommended. 

 

For more details, see:

de Lima TC, de Sobral GG, de França Queiroz AES, et al.

Characterization of lyophilized equine colostrum. 

J Equine Vet Sci. 2024;132:104975. 

https://doi.org/10.1016/j.jevs.2023.104975

Role of in-breeding in pregnancy loss

 A recent study conducted by the Royal Veterinary College (RVC) in collaboration with Cornell University sheds light on the role of inbreeding in mid and late-term pregnancy loss (MLPL) among UK Thoroughbreds. Interestingly, while inbreeding does impact MLPL, it has little effect on early pregnancy loss (EPL).

The research specifically explores the influence of genomic inbreeding levels on late-term pregnancy loss in horses. These findings provide valuable insights for breeding practices, which can help inform mating decisions to reduce the risk of miscarriages in Thoroughbreds.

 

Inbreeding, the mating of related individuals, is a common practice in the livestock industry and can be beneficial in controlled breeding programs for consolidating desirable traits within a population. However, excessive inbreeding heightens the likelihood of producing offspring with harmful homozygous recessive genotypes. This can lead to genetic disorders, reduced fertility, and decreased overall population fitness.

 

Approximately five to ten percent of equine pregnancies result in early pregnancy loss (EPL), while seven percent are lost between Day 70 of gestation and 24 hours postpartum (MLPL). Despite this, prior to this study, there had been no genomic analysis of the correlation between inbreeding levels and pregnancy loss in horses.

 

Led by Dr. Jessica Lawson, Alborada Trust Research Fellow at the RVC, and Professor de Mestre at the Baker Institute for Animal Health at Cornell University, along with former RVC PhD student Dr. Charlotte Shilton, the research team analysed DNA samples from 189 individuals. These samples included allantochorion and foetal DNA from early pregnancy loss (EPL) cases (n=37, gestation age 14–65 days), mid and late-term pregnancy loss (MLPL) cases (n=94, gestational age 70 days–24 hours post parturition), and hair or blood samples from adult UK Thoroughbred controls (n=58).

 

The study revealed that Thoroughbred pregnancies lost in mid and late gestation (MLPL) had significantly higher inbreeding metrics compared to UK Thoroughbred adult controls. Conversely, pregnancies lost early in gestation (EPLs) showed no significant difference in inbreeding metrics compared to controls.

 

These findings emphasise the importance of informed mating decisions in the Thoroughbred breeding industry. Moreover, they stress the need for further research to identify and characterise genomic changes that may prove detrimental to pregnancy.

 

Dr Jessica Lawson, Alborada Trust Research Fellow at the RVC, said: “This research provides critical evidence showing that mating highly related individuals does have a tangible effect on our breeding operations, as there is a real risk of a mare losing her pregnancy late in gestation and failing to produce a foal at all that season. 

 

“The take home from our work should be to carefully consider breeding choices that involve mating of highly related individuals as, ultimately, this may increase the chance of the foal inheriting mutations which may not be compatible with life. We are already working on the next step, looking to identify these changes so more specific advice can be provided in the future”.

 

This research was funded by the Thoroughbred Breeders Association, Horserace Betting Levy Board, the Alborada Trust, and partial PhD studentship funding from the Royal Veterinary College's Paul Mellon Trust for Equine Research.

 

For more details, see: 

Lawson JM, Shilton CA, Lindsay-McGee V, Psifidi A, Wathes DC, Raudsepp T, de Mestre, AM.

Does inbreeding contribute to pregnancy loss in Thoroughbred horses? 

Equine Vet J. 2024.

https://doi.org/10.1111/evj.14057

 

 

Edited press release. Read the original press release:

https://www.rvc.ac.uk/equine-vet/news/new-rvc-research-finds-inbreeding-is-contributing-factor-to-mid-and-late-term-pregnancy-loss-in-thoroughbreds

Assisted reproduction in Estonian sport horses

Horse embryo Credit Elina Tsopp

 If all goes according to plan, Estonia is on the brink of a pioneering achievement in the realm o
f horse breeding. The imminent birth of the first foal, conceived through a meticulously planned process, marks a significant milestone for the country. 

This innovative method (Ovum Pick-Up and Intracytoplasmic Sperm Injection (OPU-ICSI)) involves extracting an ovum (egg) from one mare, using the OPU procedure, and inseminating it using the Intracytoplasmic Sperm Injection (ICSI) technique, where a single sperm is injected directly into the egg. The embryo is then grown in the laboratory and subsequently transferred to another mare.

Ghent University in Belgium and a few private enterprises already provide an in vitro production service for horse embryos. This service has now been introduced at the University of Life Sciences in collaboration with Luunja Stables and Perila Stables, explained the initiative's leader, Elina Tsopp, a junior researcher in breeding and biotechnology at the University.

The mare, impregnated with an ICSI embryo, is located at Luunja Stables. The embryo transfer was carried out by veterinarian Ulrika Tuppits. “Trials were conducted simultaneously in both stables. The fact that pregnancy was first achieved at Luunja Stable was simply a matter of luck."

 

The trials began two years ago, and according to Tsopp, the easiest way to explain the procedure is that it is very complicated. 

 

"The ovum needs to be injected with one sperm, that is, a single spermatozoon," explained Tsopp. Considering the size of the cells this in itself is already a delicate procedure. But this still does not guarantee the successful fertilization of the ovum. Everything depends on the quality of the cells collected with the OPU procedure, the transport conditions, the quality of the sperm and several other factors, said Tsopp.

The OPU-ICSI technique is in high demand among horse breeders. “Such biotechnology helps to produce offspring from mares involved in top-level sports without disrupting their athletic careers. Furthermore, the OPU-ICSI technique allows obtaining offspring from mares 

that otherwise could not produce offspring or to use the sperm of very valuable stallions more efficiently," explained Tsopp. It's no secret that in equestrian circles, in vitro fertilization is a very hot topic. Nowadays, in addition to selling horses and foals, embryos are also being sold.

Their athletic careers may not give sport horse mares the opportunity for a traditional pregnancy, yet all stables still want to have offspring from the best horses. Now, in addition to embryo transfer, there is also the possibility of obtaining offspring from the best mares through the OPU-ICSI technique: during a quick procedure, oocytes are retrieved from the ovaries, and the horse can go straight back to sport after a rest day. The embryos are taken to the laboratory for fertilization, and the fertilized cells grow in the incubator for 7-10 days until they are ready for transplantation or freezing.

Another significant reason for using biotechnology is the high cost of semen from top stallions. A straw of semen from some stallions can cost 30,000 euros or more. Artificial insemination of a mare often requires two or three straws, and a successful pregnancy is not guaranteed. However, by using the ICSI technique, it is possible to fertilize hundreds of eggs in laboratory conditions with a single straw of semen, providing the best genetic combinations for hundreds of offspring.

Up to 20 eggs can be obtained from one mare at a time using the OPU method, which involves aspirating follicles with a long needle and a vacuum pump. The breeding season for horses falls between spring and autumn, but the OPU method allows for the retrieval of eggs throughout the winter as well. 

 

The first test tube foal in Estonia is due to be born in August 2024.

Detecting onset of foaling

 A device attached to the base of the tail was found to be useful for detecting foaling in a study in Japan.

Although most mares give birth smoothly, complications such as improper positioning of the foal can quickly become serious. Having assistance readily available during this time can be the determining factor between a successful delivery of a healthy foal and a complete disaster.

 

Mares typically exhibit few noticeable signs indicating the imminent birth, prompting stud farms to assign someone to monitor expectant mares constantly. On the other hand, individual mare owners may endure numerous sleepless nights while anxiously awaiting the foaling process.

 

An alarm that reliably indicates the onset of foaling would be extremely valuable.

 

Researchers in Japan have been assessing the value of a device that detects movement and   changes in skin temperature.

 

Takahiro Aoki and fellow workers used a device consisting of a thermistor and a tri-axial accelerometer, which they attached to the base of the pregnant mares’s tails. A comprehensive report detailing their research has been published in the journal PLoS One.

 

During the study, seventeen pregnant mares on two private stud farms were closely monitored. The sensors measured and recorded the surface temperature of the ventral tail base, activity intensity, roll angle, and y-axis acceleration every three minutes.

 

The researchers clarify that the sensors were affixed to the pregnant mares approximately one week before the anticipated foaling date (defined as 335 days from the last mating) and were kept in place until at least one day after the mares gave birth.

 

The tail sensor collected data on skin temperature (ST) within a range of 20 to 45°C, with a resolution of 0.05°C. It also measured activity intensity within a range of 0 to 102.3, with a resolution of 0.2. Additionally, the device recorded roll angle, which represents the rotation of the x- and z-axes around the y-axis, within a range of -3 to +3 rad, with a resolution of 0.05 rad. Finally, y-axis acceleration was measured within a range of -1000 to +1000 mg, with a resolution of 4 mg.

 

The researchers discovered that three physiological or behavioural indicators exhibited significant changes shortly before a horse gives birth: (1) a decrease in skin temperature below 35.5°C, (2) lying down (LD), and (3) tail raising (TR).

 

They investigated the possibility of foaling occurring within one hour after meeting one or a combination of two or three of these criteria.

 

When considering each criterion individually, they observed a sensitivity of 100% for all three indicators, but the precision was 13.1% for skin temperature drop (LST), 8.1% for lying down (LD), and 2.8% for tail raising (TR).

 

Combining two indicators resulted in a sensitivity of 100% for all combinations. The accuracies were 100% for the combination of LST and LD, 56.7% for LD and TR, and 32.1% for TR and LST. When all three criteria were combined, both the sensitivity and precision were 100%.

 

After fulfilling two or more of the indicators, the average to complete labour was found to be between 20 and 30 minutes.

 

The researchers conclude that the tail-attached multimodal device examined in the study was useful for detecting foaling.  “…the time of birth of the foal can be detected with high sensitivity and precision by combining LST, LD, and TR.”

 

They suggest that the detector may also be useful in detecting when a mare is in season as tail raising is more often seen in mares during the oestrus period.

 

For more details, see:

 

Detection of foaling using a tail-attached device with a thermistor and tri-axial accelerometer in pregnant mares

Takahiro Aoki, Makoto Shibata, Guilherme Violin, Shogo Higaki, Koji Yoshioka 

PLoS ONE (2023) 18(6): e0286807.

https://doi.org/10.1371/journal.pone.0286807

Investigating umbilical cord torsion as a cause of abortion

Approximately 1 in 25 Thoroughbred pregnancies in the UK result in pregnancy loss during mid to late gestation, a statistic that has not shown any significant improvement in the past three decades. 

In the UK, umbilical cord torsion (UCT) is recognised as the primary cause of this phenomenon, accounting for almost half of the cases that are sent for laboratory analysis. 

 

UCT occurs when there is excessive twisting of the umbilical cord, which restricts the blood supply to the foetus and eventually causes its death.

 

Interestingly, in all other countries (except Australia), the proportion of pregnancy loss attributed to UCT is much lower. In North America, the occurrence of UCT is one tenth of that in the UK. The rate of abortion attributed to umbilical torsion varies from 2.4% to 6.0% in studies conducted in the United States, while it reaches 35.7% in the United Kingdom. 

 

Umbilical cords from torsion cases tend to be longer than 85 cm on average. The reasons why certain pregnancies are more prone to develop long or excessively twisted umbilical cords, as well as the dramatic geographic variation in occurrence, are not well understood. 

 

Researchers at the Royal Veterinary College (RVC) are leading a collaboration with colleagues at Cornell University, Rossdales Laboratories and Hagyard Equine Medical Institute to explore the reason why the umbilical cord twists excessively mid-pregnancy. The research, funded by the Alborada Trust, continues the first ever comprehensive study of UCT in the world. Together, the research team hope to establish new ways of detecting the twisting prior to the pregnancy being aborted.

 

They will also characterise subcomponents and key proteins of the umbilical cord in both normal and diseased cords to identify any potential regions of the cord that could be monitored clinically. These areas will then be examined using ultrasonography in mid-gestation to assess the diagnostic potential for mares that are at risk of UCT abortion.

The researchers hope to develop novel diagnostic tools that will enable veterinarians to predict mares at risk of suffering a UCT pregnancy loss and monitor the efficacy of novel treatments for the condition. Ultimately, the findings from this project will push forward the understanding of this cause of equine pregnancy loss, and abortion more widely.    

 

Jessica Roach, Research Fellow at the RVC, said: “The generous funding from The Alborada Trust will allow us to build on our understanding of umbilical cord torsion, which is such a frustrating cause of abortion to breeders and veterinarians alike. This project brings together researchers who are leading their field and I hope that this will allow us to forward our understanding of this condition. Our aim is to develop novel diagnostic tools to identify pregnancies with a torsed umbilical cord, and ultimately prevent or decrease the risk of pregnancy loss.”

 

For more information on the study, see : https://www.rvc.ac.uk/research/projects/investigation-of-clinical-predictors-of-equine-umbilical-cord-torsion-and-abortion

Do younger parents breed faster racehorses?

 Recent research shows that increasing parental age at conception has a detrimental effect on race speed.

 When a split-second can separate the horses at the end of the race, the slightest advantage can give the winner the edge. Research from the university of Exeter found that the speed of thoroughbred horses declines as the age of their parents when they were conceived increases. 

 

Dr Patrick Sharman and colleagues at the Centre for Ecology and Conservation, University of Exeter, analysed 906,027 racing performances of 101,257 horses -   the offspring of 41,107 dams and 2887 sires. The study included data from almost 25 years of racing results, from 1996-2019, involving meetings across Great Britain. The work is published in Royal Society Open Science.

 

Dr Patrick Sharman said “The fact that parental age affects racehorse speed should be of interest to the horseracing industry.  More generally, it adds to an increasing body of evidence which points towards parental ‘state’ at the time of conception having an influence on offspring phenotype. This would have implications well beyond racehorses and the horseracing industry” 

 

They found a ‘significant effect’ of maternal age on speed, with each additional year of age at conception decreasing the offspring speed by 0.017 yards per second.  

 

This may not sound very much, but they suggest it could produce a one second difference in a race over a mile between horses born to a five-year old and a 15-year old mother.

 

Also, they found that the paternal age showed a decrease of 0.011 yards per second for every increasing year in stallion age.

 

Sharman added: “It is perhaps not surprising that offspring speed declines with increasing maternal age. It is the dams, after all, who care for the foal, first in utero, and then through to around 6 months of age. 

 

“What I find fascinating, though, is that increasing paternal age also causes a significant decline in racehorse speed. Thoroughbred stallions play no part whatsoever is raising a foal, so what is behind this decline in speed?” 

 

The authors conclude: “Our analysis identified significant negative within-parent effects of advancing maternal and paternal age on offspring speed. While we had expected to find some evidence of parental age effects, their magnitude is notable, particularly that of the previously undocumented influence of paternal age on offspring speed.” 

 

They hope that their findings will prompt research into the mechanisms by which these parental age influences are transmitted to the offspring.

 

For more details, see:

 

Evidence of maternal and paternal age effects on speed in thoroughbred racehorses

Patrick Sharman, Andrew J. Young, Alastair J. Wilson

Royal Society Open Science Vol 9, no 10 (2022)

https://doi.org/10.1098/rsos.220691

 

Is your mare due to foal?

Researchers at the Western College of Veterinary Medicine in Saskatoon, Canada, would like your help.

They are investigating how umbilical cord variations relate to  foal health. In particular, they are interested in the length of the cord, and the number and type of twists present in it. 

In light horses, the umbilical cord is usually between 30 and 80 cm long and may be twisted a few times. Excessively long cords, or those with numerous twists, may limit blood flow and affect the foal’s health.

 

Dr. Madison Ricard, a veterinary anatomic pathology resident, who is leading the study, is looking for owners of pregnant mares to take part in the research. 

 

Participation in the study will involve measuring the length of the umbilical cord after foaling and taking a photo of the umbilical cord. 

 

Information will be recorded about the mare, the foaling process, and the foal’s health at birth. There will be follow up surveys regarding the foal’s health at 7 and 30 days after birth.

 

To participate in the study, or for more details, go to:

https://wcvm-equs.ca

Assisted reproductive techniques: online collection

Assisted reproductive techniques are becoming more common in equine breeding, not least within the sport horse world. The Equine Veterinary Journal (EVJ) is sharing the latest knowledge on assisted reproductive techniques (ARTs) through a special virtual collection that is free to view until 27 December 2021.

 

While the main reason for developing the ARTs was their potential to accelerate genetic improvement by allowing more offspring to be produced from the best stallions and/or mares, early uptake in practice has been biased towards their capacity to salvage the breeding career of valuable horses suffering from persistent sub-fertility. Editor Tom Stout and guest editor Huw Griffiths have brought together a collection of 14 selected articles published recently in EVJ that have contributed to the advance of equine ARTs. 

“While some ERT techniques such as embryo transfer and in vitro production are technically complex and not yet optimised, they have proven to be powerful techniques for resolving sub- fertility,” said Tom Stout. “Further studies into factors limiting their success may not only lead to future improvements but also yield information useful to tackling specific causes of sub-fertility in mares or stallions used for natural mating or AI. This collection shares current knowledge.”

 

Ensuring that mating or artificial insemination (AI) take place close to the time of ovulation is a central part of successful breeding management. Several articles cover aspects of ensuring sperm and egg meet at the optimal time and in optimal conditions. Another discusses the challenges of creating an appropriate environment for early embryo development. 

 

In vitro production (IVP) has only become commercially viable in equine practice during the past 10 years. Parts of the collection cover the development of IVP and some of the obstacles encountered including incidences of monozygotic multiple pregnancies and potential problems with the mare of advanced age. 

 

An advantage of IVP is that the embryos are amenable to cryopreservation with no appreciable difference in pregnancy rates between freshly transferred and cryopreserved ICSI embryos. Several articles discuss methods of cryopreservation and vitrification protocols.

“As our knowledge progresses so does our capacity to use ARTs to best effect, to preserve important lineages, reduce inherited disease risks and enhance welfare,” said Professor Celia Marr, Editor of the EVJ.

“This collection makes for invaluable reading, not only for those working in equine reproduction but for those vets who have a general interest in the continued advancement of science and the inextricable and growing links ART has to successful equine breeding.”

The virtual issue will be free to view until 27 December 2021, and can be found at:

https://beva.onlinelibrary.wiley.com/doi/toc/10.1001/(ISSN)2042-3306.assist-reproductive-techniques-vi