Horse Breeding

The Changing Landscape of Quarter Horse Genetics, Part 1

December 12, 2014

Certain populations of the American Quarter Horse are losing genetic diversity, as revealed in genetic research supported by the American Quarter Horse Foundation.

horses in a cluster

“We were able to prove quite clearly that horses were in a specific genetic cluster, depending on what performance group they came from,” says Dr. Molly McCue. Journal photo

From The American Quarter Horse Journal

Talk to an equine geneticist long enough, and you are bound to hear two assertions made about the American Quarter Horse breed that sound like opposites: First, it is one of the most genetically diverse equine breeds in the world; and second, it’s becoming increasingly inbred.

Beginning in colonial America, the breed began from a diverse genetic base of largely Thoroughbred and Spanish blood that was added to and developed for roughly 200 years, focusing on producing quickness and durability. But fast-forward to the modern era of specialized American Quarter Horse performers – especially at the highest levels – and you find specialization in the horse-breeding herd, too; specific groups of individuals used to produce those top performers. Read the rest of this entry »

Stallion Reproductive Evaluation

December 5, 2014

It’s always a good idea to have a reproductive evaluation performed on your stallion so you’ll know what to expect and can identify potential problems.

Knowing your stallions reproductive health is important to the success of any potential breeding program

Knowing your stallion’s reproductive health is important to the success of any potential breeding program. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

Reproductive evaluations are typically performed on stallions for three reasons:

  1. Estimate future reproductive potential
  2. Evaluate prior to purchase
  3. Determine causes of poor reproductive performance

The evaluation should encompass general health of the horse, behavior, mating ability, genital examination, semen evaluation and other parameters. In most cases, the examination can be performed in one day. Here are the important components of a stallion reproductive evaluation: Read the rest of this entry »

Horse-Breeding Dilemma Resolved

November 21, 2014

Sometimes all it takes to manage mare reproduction problems is working closely with your veterinarian to find the program that works for your mare.

mare and foal

With proper care and management, a problem mare can conceive a foal. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

In the January 2011 issue of the Journal, I presented the case of a 15-year old mare with a history of subfertility. A series of tests yielded a final diagnosis of fungal endometritis – the mare had a yeast infection in her uterus. This column will describe the treatment and outcome after the first breeding of the year.

Fungal infections of the equine uterus can be difficult to treat and will often recur if all of the organisms aren’t eliminated. Read the rest of this entry »

Stallions That Accumulate

November 14, 2014

Proper management can help stallions with “sperm accumulation syndrome” still have a successful horse-breeding career.

stallion sperm mobility chart

In stallions affected by sperm accumulation, sperm numbers in the first collection will be very high and sperm motility will be low. The number of sperm per ejaculate typically decreases and the percentage of live, motile sperm increases after two to four days of daily collection. Courtesy of Dr. Patrick McCue

By Dr. Patrick McCue in The American Quarter Horse Journal

A 3-year-old stallion was referred to the clinic after an initial semen evaluation at home suggested that there were no motile spermatozoa in the ejaculate. It was the first time the horse had ever been collected.

The horse was in excellent body condition. The total scrotal width was measured at 9.3 cm, well above the minimum of 8.0 cm for a breeding stallion. A semen collection attempt was performed at 10 a.m. Read the rest of this entry »

Horse-Breeding Problems: Pyometra

November 7, 2014

Infectious fluid in the uterus can mean poor future fertility for a broodmare.

mare and foal

Pyometra carries a very guarded-to-poor prognosis for future fertility. The condition may be associated with a physical obstruction or functional defect in the cervix. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

A 19-year-old American Quarter Horse mare came to the clinic for evaluation of a vaginal discharge. The mare had given birth to eight foals in her lifetime, and the last foal was born five months prior to the clinic visit.

The foaling was normal, and the mare was left open and not rebred. The goal of the exam was to determine the source of the vaginal discharge and provide a prognosis for future fertility. The mare was in good body condition for her age, and her external reproductive conformation was normal. Read the rest of this entry »

Predicting Foaling

October 31, 2014

Technology plus clinical signs equal success in the horse-breeding business.

pregnant mare

The last few days prior to foaling can be especially tedious for the horse owner, farm manager or foaling staff. Know the foaling signs to watch for. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

Clinical signs of impending foaling begin subtly a month or so prior to the due date. Changes become more dramatic and occur more rapidly as the day of foaling approaches.

The first noticeable change is in the mare’s mammary gland, which begins to enlarge two to six weeks prior to term. Some mares can develop a large amount of edema around the udder before the gland itself becomes enlarged. Mammary gland development will be much more pronounced in mares that have previously had foals than in maiden mares. The teats or nipples will remain relatively flat until the last few days prior to foaling, at which time they will engorge or fill with milk.

The mammary gland secretion changes from a clear straw-colored fluid to a more turbid milk-like substance as the due date draws near. The secretion becomes thick and honey-like as colostrum develops in the last few days prior to foaling. A thick, waxy material of dried colostrum can accumulate at the ends of the teats 24 to 48 hours prior to foaling. This “waxing” is a classic sign that foaling is imminent. The extent of waxing can range from tiny droplets to elongated candlewax-like formations that project an inch or more from the teat ends. As a general rule, most mares that wax will foal within 24 to 72 hours. However, not all mares wax up, and the time from waxing to foaling can vary.

After your mare has her foal, you’ll need to determine what color it is. Sometimes, it’s straightforward, but in other cases, you might need a little bit of a guide. Download AQHA’s FREE Horse Color and Markings Chart to help you.

In the last two to three weeks of pregnancy, the abdominal muscles relax, causing a pronounced dropping of the abdomen, especially noticeable in older mares. During the last week prior to foaling, the ligaments, muscles and other structures surrounding the mare’s pelvis and perineum soften in preparation for birth. The vulva becomes relaxed in the hours prior to foaling.

The mare’s behavior often changes during the last few days or hours preceding foaling. Mares near term tend to isolate themselves from other mares, go off feed and pass small amounts of manure or urine frequently.

foaling-signs-chart-1031201There are several tests to predict the onset of labor in addition to close observations. Calcium concentrations in mammary secretions have been used successfully for many years to predict impending labor. Calcium concentration in milk increases sharply as the mare approaches the time of foaling.

It is recommended that testing be initiated several days prior to the expected due date. Testing in mares with an unknown breeding date should begin when significant udder development is noted and a small amount of secretion can be obtained.

One commercial kit uses a test strip that is dipped into a specific dilution of milk and distilled water and observed for color change in any of five test squares. The chance of foaling within 24 hours increases as the number of squares changing color increases.

By downloading AQHA’s FREE Horse Color and Markings Chart, you can easily determine what color your new foal is. It provides descriptions and photos of the 17 AQHA-recognized horse colors.

A second test kit is based on a chemical reaction, measuring calcium carbonate. Again, high calcium levels suggest a high probability of foaling, while low calcium levels suggest that the mare is less likely to foal in the next 12 to 24 hours.

More recently, changes in the acidity or pH of a mare’s milk have been used to indicate that foaling is near. Mare milk pH is usually around 7.0 to 7.4 in late gestation. A dramatic drop in milk pH to approximately 6.4 or lower occurs the day prior to foaling. Commercial pH test strips, calibrated in the range of 5.5 to 8.0, can be used as an on-farm indicator of impending labor.

The last few days prior to foaling can be especially tedious for the owner, farm manager or foaling staff. Late-term pregnant mares should be monitored closely to optimize services of farm or veterinary personnel, maximize use of foaling space and to assist with the safe delivery of the foal if needed.

Horse-Breeding Chemistry

October 24, 2014

Sometimes, synthetic progestins that are used on mares are also used on unruly stallions to calm their demeanor. Does this affect their performance in the breeding shed?

Horse owners and trainers should use caution and discretion when contemplating the use of altrenogest in young performance stallions destined for a future reproduction career. Journal photo

Horse owners and trainers should use caution and discretion when contemplating the use of altrenogest in young performance stallions destined for a future reproduction career. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

Regumate or altrenogest, a synthetic progestin approved for suppression of estrus in mares, is also used to help maintain pregnancy in mares determined to be at high risk.

Regumate is occasionally administered off-label to stallions to suppress undesirable male behavioral characteristics that interfere with the horse’s training or athletic performance. In horses, products can be used off label if there is a valid veterinary-client-patient relationship and there is no licensed product on the market that treats the condition you’re trying to treat. Any liability for the product’s safety and efficacy lies with the prescribing veterinarian.

So does Regumate have adverse effects on reproductive performance in stallions? Progestins are known to inhibit pituitary luteinizing hormone secretion. In the male, LH stimulates Leydig cells of the testes to produce testosterone for spermatogenesis and libido. Read the rest of this entry »

Horse-Breeding History: Wilywood

October 17, 2014

This descendant of Driftwood sired classy and talented ranch and rodeo horses with great dispositions.

Robert Eliason, 17, ropes a calf on Wilywood without a bridle. Photo courtesy of Tom Eliason

Robert Eliason, 17, ropes a calf on Wilywood without a bridle. Photo courtesy of Tom Eliason

From The American Quarter Horse Journal

“Wilywood promoted himself,” Tom Eliason said with a smile. “Joann and I had eight children, and feeding the kids was always ahead of showing a horse. But the things Wilywood did for our family are beyond any numbers or statistics. Nobody can ever tell me he was just another horse.”

Tom would know. He was training horses professionally before he finished high school, and has bred Quarter Horses for four decades. He trained and rode Mr Flintrock, the 1977 AQHA world champion heeling horse, and debuted Two Eyed Jack in reining (they won). Read the rest of this entry »

Horse-Breeding Compatibility

October 10, 2014

Some pairings just don’t work, and that seemingly perfect mare-stallion combination fails to result in pregnancy.

unhappy mare

Sometimes a typically easily bred mare and a usually very fertile stallion just don’t have the right genetic mixture. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

The 12-year-old mare had already successfully carried four foals to term. She was known as an easy breeder because she always settled on either the first or second cycle. The mare had conceived in previous years after having been bred with either frozen semen or cooled semen.

This year, the owner wanted to breed her to a local stallion of known good fertility and get her pregnant early in the season. Nice and simple. Unfortunately, it didn’t happen that way.

The previous fall, we suggested the mare be put under lights. Beginning about December 1, we had recommended that the mare be housed at night in a stall and allowed daily outdoor turnout. Read the rest of this entry »

A Horse-Breeding Problem

October 3, 2014

Some mares have trouble getting in foal and staying in foal. Dr. Patrick McCue sheds light on the situation with some options to help your problem mares.

mare without foal

Problem mares need to be managed as individuals. If your mare has trouble getting in foal and staying in foal, she might be a problem mare that needs to be evaluated by a veterinarian. Journal photo

By Dr. Patrick McCue in The American Quarter Horse Journal

Everyone involved in the equine breeding industry would prefer to have every mare become pregnant and stay pregnant, but that isn’t realistic. It has been estimated that end-of-season pregnancy rates on well-managed farms should approach and may exceed 90 percent. The rate of pregnancy loss is usually 5-10 percent.

The most accurate measurement of fertility in mares is pregnancy rate per cycle. General factors that may decrease pregnancy rate per cycle include abnormalities of the reproductive tract, age-related reproductive changes, obstetrical injuries, poor quality semen and poor management. Overall, pregnancy rate per cycle typically averages 50 percent. Read the rest of this entry »

A Horse-Breeding Matriarch

September 26, 2014

Pretty, versatile and talented, Chubby Time could’ve been a poster girl for the American Quarter Horse breed.

Scotch Bar Time

Chubby Time is credited for the versatile, good-minded offspring of her Hall of Fame colt, Scotch Bar Time, pictured here. AQHA file photo.

From The American Quarter Horse Journal

Even if she didn’t have one of the best names ever, Chubby Time (by Spot Time and out of Hat Eight Two by Chubby’s Red Bud) would be remembered for her versatility, accomplishment and good nature, in other words, for what makes the American Quarter Horse so beloved today.

A 1964 model, she earned her performance Register of Merit at the age of 6 and her AQHA Champion title at the age of 20. In between, Chubby Time earned points in open halter, western pleasure, western riding and tie-down roping, and gently provided an AQHA director with his first show pen experience. She also produced four offspring, including Scotch Bar Time, an inductee in both the American Quarter Horse Hall of Fame and the National Snaffle Bit Association Hall of Fame. Read the rest of this entry »

Horse-Breeding History: Kaweah Bar

September 22, 2014

The “Palomino Express” was ornery, but he could run.

kaweah bar race

Kaweah Bar, lovingly known as the “Palomino Express,” was inducted into the American Quarter Horse Hall of Fame in 1998. Photo by Milt Martinez.

From The American Quarter Horse Journal

Kaweah Bar won his first start, at Bay Meadows in 1968, by 3 1/2 lengths. That was just a sign of things to come from the “Palomino Express,” the darling of the $2 bettors.

The 1966 gelding didn’t look like your typical racehorse. He wasn’t the lean, trim type, but he also wasn’t the blocky, bulldog cow horse. Kaweah Bar was somewhere in between, but he could run.

Kaweah Bar won 21 stakes races, 12 of which are now graded events, and 38 races overall in his nine-year career. He’s the only horse to repeat as world champion without doing it back to back. All told, he won 12 racing championships and earned $386,516 in his career. Read the rest of this entry »