
Reproduction
What we do
Dedicated to high-quality animal care, the Georgia and Philip Hofmann Center for Animal Reproduction offers reproductive evaluation, diagnostics, and treatment from a team of four board-certified reproduction specialists and a board-certified behaviorist.
Our Reproduction Services
Functions, Forms, and Programs
Located one-mile southwest of the New Bolton Center campus on approximately 25 acres, the Center can house up to 19 horses in separate wings and stalls for cattle and small ruminants. The large spacious breeding shed with rubber flooring, stimulus mares for semen collection, a hydraulic breeding mount that can be adjusted to accommodate your stallion’s height, full laboratory with state-of-the-art equipment, examination stocks for mares, handling system and chute for our bovine patients, and on-site embryo transfer recipient mare herd.
Our Reproduction Services
Functions, Forms, and Programs
Located one-mile southwest of the New Bolton Center campus on approximately 25 acres, the Center can house up to 19 horses in separate wings and stalls for cattle and small ruminants. The large spacious breeding shed with rubber flooring, stimulus mares for semen collection, a hydraulic breeding mount that can be adjusted to accommodate your stallion’s height, full laboratory with state-of-the-art equipment, examination stocks for mares, handling system and chute for our bovine patients, and on-site embryo transfer recipient mare herd.
Mare Services
The Georgia and Philip Hofmann Center for Animal Reproduction provides a wide range of mare services.
- The Hofmann Center offers a fertility work-up package for mares to determine if there are problems that may be associated with infertility. The package includes:
- Palpation and ultrasonographic evaluation of the mare’s reproductive tract per rectum
- Uterine culture
- Uterine cytology
- Uterine biopsy
- Manual, digital evaluation of the cervix
- Vaginal speculum examination
- For those mares requiring additional diagnostics, we also offer hysteroscopy, low volume uterine lavage with culture and cytology, endocrine testing and cytogenetic analysis.
- If you are interested in a fertility work-up for your mare, please contact our reproduction team today by calling 610-925-6364.
- The Hofmann Center offers breeding packages for mares being inseminated with fresh, chilled or frozen semen. The packages include all necessary transrectal ultrasonographic examinations and artificial inseminations. Board, medications and other treatments (ie. uterine lavage, uterine infusions) are additional.
- Mares managed for frozen-semen breedings are carefully monitored throughout the daytime and evening hours and are inseminated via deep uterine horn insemination, timed carefully to coincide with ovulation. All mares, including those with foals, receive personalized care including daily individual turnout in large outdoor paddocks.
- The Hofmann Center offers a wide variety of other reproduction services to mare owners including:
- Pregnancy diagnosisFetal gender determinationManual twin pregnancy reductionTransvaginal twin pregnancy reductionTreatment of uterine infections (bacterial and fungal)Endometrial biopsy interpretation (in conjunction with the Pennsylvania Animal Diagnostic Laboratory System, PADLS). If you are interested in submitting an equine endometrial biopsy for processing and interpretation, please fill out the Endometrial Biopsy Submission Form (PDF), and contact PADLS Mammalian Pathology Lab for more information, fees, and timeline for results.
- Surgery to improve mare perineal conformation
- Evaluation of mid- and late-term pregnancies
- Diagnosis and treatment of uterine and ovarian tumors
- Uterine cyst removal
- Cervical laceration repair
- Ovariectomy
- Foaling packages for high-risk mares
- Laparoscopic treatment of blocked oviducts
Assisted Reproduction Services
Stallion Services
The Hofmann Center offers stallion semen collection services. The center boasts a spacious breeding shed with rubber flooring, hydraulically adjustable breeding mount, experienced stallion handlers and fully equipped laboratory for semen analysis and processing. Semen can be collected from your stallion while he is mounted on a breeding mount or mare.
We also are happy to manage both mares and stallions for natural service when needed.
Our team specializes in alternative methods of semen collection such as ground semen collection and pharmacologically-induced semen collection.
These techniques can prove invaluable when managing disabled stallions or stallions that, for other reasons, cannot have semen collected by standard means.
All semen undergoes a complete analysis by one of our veterinary specialists, including computer-assisted evaluation of sperm motility, prior to packaging and shipment. Shipping containers are available for purchase or rental.
All semen is thoroughly analyzed by veterinary specialists before packaging and shipping. Containers are available for purchase or rental. Stallions receive a summary of semen quality and shipments at the end of each breeding season. Semen collection services are available by appointment Monday-Friday and with prior arrangements on weekends.
To book a collection, contact the team at (610) 925-6364.
The Hofmann Center offers training services for stallion semen collection. The center boasts a spacious breeding shed with rubber flooring, experienced stallion handlers, board certified reproduction specialists and stimulus mares (ovariectomized and mares in natural estrus).
Our experienced team can train your novice stallion to mount the breeding mount or stimulus mare for semen collection in an artificial vagina. We also can introduce novice stallions to live cover using our seasoned mares.
In addition, we provide training for semen collection on the ground (“ground collection”) and specialize in assisting problem stallions.
The Hofmann Center offers semen freezing services. The center boasts a spacious breeding shed with rubber flooring, experienced stallion handlers, board certified reproduction specialists, reproductive laboratory and stimulus mares.
Both before and after freezing, a careful semen analysis is performed, including computer-assisted sperm motility analysis, evaluation of sperm morphology, and fluorescence-based sperm cell counting.
An automated freezer is available to more carefully control the freezing process. Frozen semen can be stored at the Hofmann Center for a quarterly fee. Transport containers are available for rent if frozen semen needs to be transported to another facility.
In addition to routine semen freezing, the Hofmann Center also offers epididymal semen freezing. Epididymal sperm can be harvested directly from the testicular duct in recently deceased stallions or following castration. This allows for preservation of a valuable stallion’s genetic material, even after unexpected death.
If you are considering the purchase of a breeding stallion, if you have a stallion whose fertility is uncertain, or if you are retiring a performance horse to a breeding career, the Hofmann Center offers a wide range of fertility evaluations designed to fit your needs – from simple semen evaluations to complete fertility workups including the most advanced semen analysis tests and testicular imaging.
We routinely work with stallions breeding only a few mares to stallions breeding hundreds of mares each year and we are happy to put together an evaluation that will most accurately allow us to assess your stallion’s potential fertility.
For stallions with fertility problems, our experienced veterinarians can provide not only the best in diagnostic testing, but also management recommendations, and advanced semen processing techniques to maximize pregnancy rates. We can remove ‘toxic’ seminal plasma and even filter semen to remove defective sperm from an ejaculate. Low-dose, deep horn insemination is readily available for mares bred to subfertile stallions with low sperm numbers. For the most severely subfertile animals, sperm can be frozen and made available for intracytoplasmic sperm injection (ICSI). We also specialize in comprehensive evaluations for stallions with behavioral and ejaculatory problems. A team of experts including our board certified reproduction specialists, board certified equine behaviorist and our experienced stallion handlers will work together to find a solution to your stallion’s problems. Having your stallion evaluated with us allows for a ‘whole horse’ approach to the problem and access to all the state-of-the-art facilities available at New Bolton Center. Together with our board certified imaging specialists, surgeons and internists, we can design a customized, comprehensive evaluation plan for your stallion designed to identify even subtle problems that can adversely affect reproductive function.
Forms for Mare and Stallion Procedures
Food & Fiber Animal Services
The Hofmann Center offers a wide variety of fertility services for food and fiber animals:
- Bull breeding soundness evaluations (performed on farm or at the center)
- Ram breeding soundness evaluations (performed on farm or at the center)
- Female camelid breeding soundness evaluations
Our reproduction clinicians also collaborate with the other board certified specialists at New Bolton Center to evaluate male, female and pregnant food and fiber animals that present to the hospital for illnesses and injuries related to the reproductive tract.
Equine Behavior Clinic
Our Equine Behavior Program and Laboratory at New Bolton Center has grown from within the Section of Reproductive Studies. Since the early 1980s, the program has had research as its core activity. The program has included involvement in related clinical and teaching in the veterinary school and continuing education programs nationally and internationally.
We offer telephone consultations, appointments at our facility or your farm. You can learn more about the Equine Behavior Short Courses below.
- Weaving
- Cribbing
- Pacing
- Headshaking
- Developmental
- Foal Behavior
- Compliance with Management
- Procedures Aggression
- Head-shyness
- Social Grouping and Separation Problems
- Libido
- Erection Ejaculation
- Rowdy Behavior
- Handling Issues
- Breeding Shed Facilities and Design Related to
- Behavior Self-mutilation
- Hyperactive Stereotypes (Weaving, Pacing, Cribbing)
- Mare Foal Interaction Problems
- Estrus Cycle Related Performance Problems
- Stallion Like Behavior in Mares
Our Care Team

Reproduction Service Chief
Tamara G. Dobbie, DVM, DACT
Associate Professor of Clinical Reproduction, Large Animal
Clinicians
Director of Hoffman Center
Residents and Staff
Luisa Correa, DVM
Resident, Large Animal Theriogenology
Leslie Sandoval Rosales, DVM
Resident, Large Animal Theriogenology
Carolyn Rosazza
Reproduction Technician
Jess Edstrom
Stallion Handler
Ben Guessford
Stallion Handler
Equine Behavior Short Courses
If you have questions about courses and dates please contact Sue McDonnell at (610) 925-6221 or suemcd@vet.upenn.edu
- Classes are usually held from 8:00 AM to 4:00 or 4:30 PM
- CE: 16 Hours Continuing Education Curriculum Classes
- Tuition: $500 for day 1 only, $900 for 2 days.
- Location: 382 West Street Road Kennett Square, PA 19348.
From time to time, the Equine Behavior Program offers short courses on a breadth of topics. The courses are taught by New Bolton Center faculty members Sue McDonnell, PhD and Patricia Sertich, PhD.
These courses are presented by the Havemeyer Equine Behavior Lab and the Georgia and Philip Hofmann Research Center for Animal Reproduction, University of Pennsylvania, New Bolton Center
- Two day course for veterinarians, horse owners, breeders, trainers, stallion handlers, vet techs, behavior specialists, and animal science, behavior, and veterinary students/residents
- Focusing on concepts and skills for safe, efficient handling and general management of breeding stallions
Day 1
- The Basics of Stallion Restraint
- Stallion Handling for Natural Cover
- The Basics of Mare Restraint
- Stallion Handling for Dummies (Dummy Mounts)
- Pasture Breeding
- Lessons from Free-Running Equids, Including a Tour of a Semi-Feral Herd
- Hands-On Stallion Handling Opportunity
- Individualized Coaching on Stallion Handling
Day 2
- Breeding Shed Layout and Equipment
- Starting a Novice
- How to Correct Biting, Rearing, Charging, and Other Bad Habits in the Breeding Shed
- Tips and Tricks For Handling the Older or Disabled Stallion
- Tips and Tricks for Working with Limited Personnel
- Common Breeding Behavior and Fertility Problems of Stallions
- Hands-On Stallion Handling Opportunity
- Individualized Coaching on Stallion Handling
Two-day Course for veterinarians, animal behavior clinicians, animal science students, horse owners, and managers.
- Focusing on normal and abnormal behavior of horses, with topics specific to those with serious interest in horse behavior.
Day 1
- How horses communicate
- Learning in horses
- Discussion of natural horsemanship and other popular training methods
- Behavior modification for common problems such as trailering problems, injection shyness
- Stereotypies: cribbing, weaving, pacing, head shaking
- Current methods of veterinary behavior evaluation and therapy
- Tour of a semi-feral herd
Two‐Day Course with both classroom discussion and hands‐on experience
Open to: Students, owners, trainers, veterinarians, farriers and anyone at any level of skill and expertise with a serious interest in understanding horse behavior and “misbehavior.”
Focusing on: Avoiding, rehabilitating, and managing common horse behavior and training problems
Loading and transportation difficulties, such as treatment aversions (eye and oral medication, needle sticks, rectal temping, genital examination, etc.)
Difficulties with ordinary ground handling procedures (catching, haltering, leading, tacking, mounting)
Food‐related aggression, stereotypies, rearing, biting, pawing, bolting when turned out, and gate rushing
This course could be called “how to behave so a horse behaves as you wish.”
Classroom sessions touch on how animals learn, the natural basis and “man‐made” factors contributing to the common undesirable equine behaviors, the simple tools, and techniques for animal behavior modification.
Hands‐on will include demonstration, participant practice opportunities, with coaching for various recommended popular and advanced techniques.
Specific protocols and equine‐specific tips will be offered for common behavior modification techniques including acclimation, systematic desensitization, counter‐conditioning, clicker and target training, and all‐positive reinforcement vs. pressure and release vs. punishment.
One-day Course for Owners, Breeding Farm Managers, and Veterinarians
Day 1
- Breeding management of the mare when using fresh, cooled-transported or frozen semen.
- Common causes of infertility in the mare and breeding the “problem” mare.
- The normal events of pregnancy between fertilization and day 100 of gestation.
- Early pregnancy failure.
- Embryo transfer and newer assisted reproductive techniques.
- Two-day Course: for veterinarians, horse owners, breeders, trainers, stallion handlers, vet techs, behavior specialists, and animal science, behavior, and veterinary students/ and residents
Day 1
- Reproduction of equids under natural conditions, including normal behavior of the pregnant and foaling mare and foal development.
- Maternal behavior and bonding problems and solutions.
- Raising an orphan foal.
- Normal behavioral development of the foal.
- Early intensive handling of foals.
- Least stress weaning methods.
- Raising the user-friendly foal and horse.
Day 2
- Understand the changes your mare is experiencing.
- When will she foal? Signs of impending parturition.
- Tools to help you catch the big event.
- Review of the normal events of delivery.
- Examination of the afterbirth, the mirror of fetal life.
- Induction of parturition.
- You have waited 11 long months. What is the rush? Dystocia.
- What can go wrong, and what you can do until your veterinarian gets there.
- Care of the post parturient mare.
- How to spot serious life threatening problems.
- High risk pregnant mares.
- Health care of the foal.
- Five-day Continuing Education Experience with Both Classroom Presentation/Discussions and Hands‐On Experience in Methods of Studying Horse Behavior under Natural Social and Environmental Conditions Using our on‐campus semi‐feral herd as a living laboratory for the course.
- Open to students of any age or level of experience, owners, trainers, veterinarians, farriers and anyone at any level of skill and expertise with a serious interest in better understanding horse behavior with an introduction to ethological field study methods.
Includes two classic text-books, various hand-out readings, and all other materials needed for the course. Opportunities will be provided to photograph horse behavior for teaching purposes.