Estrous Cycle

Article

See the Light: Advancing the Breeding Season for Early Foals

October 12, 2008

Horse breeders face a dilemma every year as the breeding season nears. Should they breed for early foals or breed their mares to foal out in the spring and summer? The fact that all foals in the northern hemisphere share the same... Read More

Article

Ovariectomy an Option for Performance Mares and Molly Mules

February 19, 2008

Lacey is beautiful, full of personality, and very athletic--for a mule, that is. Her owners plan on showing their cherished mule when she is ready, but they face an obstacle that all owners of female mules or mares go through--heat cycles.

... Read More

Article

Progesterone Test Makes Reproductive Management Less of a Nightmare

November 13, 2007

New research has revealed that a commercially available progesterone test is reliable and practical, and it can help veterinarians manage breeding mares more efficiently.

According to researchers from the College of Veterinary Medicine at... Read More

Article

Inducing Ovulation With Recombinant Equine Luteinizing Hormone

July 29, 2007

Manipulating the estrous cycle in mares is a big part of many breeding operations, and medications play various roles in the process. There are several options for inducing ovulation, including human chorionic gonadotropin (hCG),... Read More

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Repro Updates

March 23, 2007

Equine reproduction was covered at the 2006 AAEP Convention including foaling, venereal disease, breeding, etc... Read More

Article

hCG and Ovulation

February 14, 2005

Managing a mare's estrous cycle is an integral part of breeding management, and human chorionic gonadotropin (hCG) is one hormone option for doing just that. Patrick McCue, DVM, PhD, Dipl. ACT, associate professor of equine science at Colorado Stat... Read More

Article

Prostaglandins: Reducing Drug Costs and Side Effects

February 14, 2005

A major use of prostaglandin is to manipulate mares' estrous cycles. Some side effects observed when mares are treated with labeled doses of these medications include sweating and colic, and as a result owner distaste for using the drugs is growing.... Read More

Article

AAEP 2003: Multiple Ovulations

January 31, 2004

There are three major reasons to attempt to have a mare "superovulate" or ovulate more than one follicle at a time. First, in embryo transfer programs there is a greater chance of recovering an embryo with superovulation, thus reducing the... Read More

Article

Optimizing Implant Therapy in Cycling Mares

January 01, 2004

Deslorelin acetate implants (Ovuplant from Fort Dodge Animal Health) have proven highly successful at inducing ovulation in mares. Implanted mares typically ovulate within 48 hours. Unfortunately, despite administration of prostaglandin during... Read More

Article

Early Season Breeding: Let There Be Light!

October 01, 2003

Because of the demands of competition and sales, following the natural reproductive cycle dictated by Mother Nature often doesn't fit into man's breeding program. While Mother Nature's time frame stipulates that the mare should be receptive to... Read More

Article

Pregnant Mares in Heat?

September 01, 2003

Can you supply me with a veterinary explanation on whether a mare that is in foal can come back into season? ... Read More

Article

Marbles Keep Mares Out of Heat

March 01, 2003

Mares in performance careers are sometimes a frustration to their trainers and riders because during estrus, they can have difficulty concentrating on their work or have "behavioral problems." Many horse owners resort to hormone therapy to keep... Read More

Article

AAEP Convention: Reproduction

March 01, 2003

The reproduction session was something of an A to Z seminar. It started with discussions on endometrial echotexture (ultrasound results) and using computer analysis to determine when a mare will ovulate, or has ovulated, and along the way... Read More

Article

AAEP 2002: Reproduction

February 04, 2003

The reproduction session at the annual AAEP meeting in Orlando, Fla., was something of an A to Z seminar with an international flavor. It started with speakers from North America presenting discussions on endometrial echotexture (ultrasound... Read More

Article

Purina Veterinary Conference 2002

October 16, 2002

Only 20 miles from downtown St. Louis, Mo., is a 1,200-acre research farm owned by the nutrition company Purina Mills. On Oct. 3-5, 140-plus veterinarians and another 50 Purina Mills representatives gathered to tour that research facility and... Read More

Article

Acupuncture and Microdose Prostaglandin in the Mare

May 01, 2002

Prostaglandin F2 alpha (PG) is used to shorten a mare's cycle and hasten ovulation for breeding. Unfortunately, the standard PG dose (5 mg) also causes undesirable side effects, including sweating, trembling, increased heart rate, and... Read More

Article

Scientists Uncover New Way to Assess Ovulation

February 13, 2002

Veterinarians generally assess whether a mare has ovulated and is ready to breed by rectal palpation. However, new research suggests that a mare’s blood plasma sample can tell the veterinarian just as accurately that ovulation has occurred. The... Read More

Article

Ovulation

November 01, 2001

There is a rhythm to nature. Season follows season, with each having a specific purpose to serve in the grand scheme of things. There is a time for planting, a time for growing, a time for harvesting, and a time for resting to prepare for the... Read More

Article

Ovuplant: Improving the Odds

October 15, 2001

If you're a breeder, frankly, it pays to be in the livestock business. Cattle, sheep, goats, and pigs all make life easy for those trying to produce young stock--they are all "facultative-induced ovulators," meaning that matings early in their... Read More

Article

Superovulation

October 11, 2001

In the continuing effort to increase the fertility of horses there comes a new weapon--superovulation. Inducing a mare to ovulate multiple oocytes can translate into producing more foals from selected females. Assisted reproductive technology ca... Read More

Article

Teasing Mares

October 08, 2001

Teasing mares can be a time-consuming and boring procedure, but it is essential if one is to detect when a mare is in estrus. Unfortunately, all mares do not react to teasing in the same manner, so one approach doesn't suit all.... Read More

Article

Oxytocin and Maternal Recognition of Pregnancy

October 03, 2001

A research report from the laboratory at the Gluck Equine Research Center at the University of Kentucky noted that it is well-established that early conceptus loss (the embryo and its... Read More

Article

AAEP Convention Topics Preview: Reproduction

January 01, 2001

The latest information on scores of topics is presented at the AAEP convention; we can't report on them all, but we do try to bring you a representative sampling. This year, many of the topics can be grouped into five categories: fighting... Read More

Article

Regulating Estrus in Mares

December 01, 1998

Having mares come into estrus at regular intervals can be an important assist in maintaining his fertility.... Read More

Article

Sub-Fertile Mares

February 01, 1998

A broodmare which fails to conceive or carry a foal to term can be an emotional and financial liability. For the backyard breeder, the liability might be primarily emotional, when that special mare you wanted to produce your next trail horse or... Read More