Leading veterinary school UC Davis has welcomed its first foal born by in-vitro fertilisation with the birth of a very special colt who has been two decades in the planning.
The foal’s birth at midnight on a warm summer evening in the barns at the UC Davis veterinary hospital was watched over by Dr Bruce Christensen, chief of the hospital’s Equine Reproduction Service.
The colt was born thanks to the use of intracytoplasmic sperm injection (ICSI) – a technique of “bypassing” standard IVF by injecting a sperm directly into the egg.
But the youngster’s origins go back almost a quarter of a century.
While raising a teenage daughter more than 20 years ago, Carol Alonso took up dressage riding with her daughter. Now 73, Alonso still rides competitively and still competes with the horse she bought 22 years ago – El Gavilan, an Andalusian. Alonso always wanted a Spanish horse, and searched far and wide to find El Gavilan, whose pedigree is 600 years long. She reluctantly had him gelded shortly after buying him, but had the foresight to freeze some of his semen in hopes of one day finding just the right mare to match his prowess.
At 24, El Gavilan is still going strong so Alonso felt it was finally time to find a Spanish mare to breed to him. Alonso wanted a mare that could compete in the upper levels of dressage, as El Gavilan was able to accomplish. She found that match to be a tall order. Having literally searched the world over, Alonso decided to curtail her expectations a bit, and found a non-Spanish mare in Illinois that she thought would be a good match. The mare, Zholani, was half thoroughbred and half shire.
Alonso started showing Zholani and had great success with her. She knew she had finally found the right match for El Gavilan so she met with the equine reproduction specialists at UC Davis. After a few unsuccessful attempts of artificial insemination on Zholani, Dr. Christensen suggested that Alonso enrol Zholani in his research study involving ICSI fertilization.
Unlike the normal process of in-vitro fertilization (which generally doesn’t work with horses), the ICSI process involves injecting a single sperm into an egg extracted from a mare. The embryo then develops in a lab for a week before being implanted in the mare. Few facilities in the country have the capability to perform ICSI fertilizations, so UC Davis worked in collaboration with the Equine Embryo Laboratory at Texas A&M University.
Although human IVF has been successful since the 1970s, success rates in horses hover between zero and 30%, and very few foals have been born using this technology.
After extracting follicles from Zholani’s ovaries, six of her eggs and El Gavilan’s sperm were shipped to Texas A&M, where two viable embryos were created. Because of Zholani’s inability to previously get pregnant, the team felt it was a safer option to use a recipient mare to carry the pregnancy. A recipient mare would also allow Zholani to continue in competition. The second embryo was frozen for future use.
A mare named Kaikoura was chosen from UC Davis’ Center for Equine Health (CEH) to carry the embryo. Due to the criticalness of the early period of an equine pregnancy, Kaikoura was held at CEH for the first six weeks before she was taken to Alonso’s barn for the duration of the pregnancy. A few weeks before her due date, Kaikoura was brought back to UC Davis and put on “foal watch.”
Lord Nelson was born on Alonso’s 45th wedding anniversary, which also happened to be her husband’s birthday. Having celebrated all day, the Alonsos were exhausted when they received Dr Christensen’s midnight phone call, stating he was witnessing the birth. They drove nearly two hours to Davis in the wee hours of the morning to see the new arrival.
PICSI (pronounced Pixie), as Alonso likes to call Lord Nelson, will begin his career training for dressage as soon as he matures. His lineage has Alonso excited for his prospects. This has been a dream come true for her, having seen through a project more than two decades in the making.