Breeding Thoroughbred Racehorses Blends Art and Science: Part 2
There’s nothing quite like seeing a new foal take its first steps and nurse for the first time. This event is highly anticipated by horse owners and breeders after almost a year of waiting (the normal gestation period in mares ranges from 335 to 345 days), watching, and anticipating. It's a time to rejoice when the brand new foal arrives, and mare and foal are healthy.
A great deal of work goes into ensuring the new baby is healthy, happy, and on their way to racing glory. Mare nutrition is fundamental during gestation and lactation as they need more fuel, especially when producing milk. It’s hard work for a mare to maintain her own body condition and produce milk for the young foal!
About four to six weeks prior to the anticipated foaling date, mares are boosted with vaccines so that their colostrum (first milk) contains high levels of antibodies. It is VITAL that foals receive colostrum from their mother as soon as possible after birth. Foals are born with very little immunity and gain immunity by what is known as passive transfer. The foal must drink the colostrum produced by the mare to build up these antibodies. A foal’s system is designed to digest colostrum only in the first 12 or so hours after birth, so time is of the essence. The antibodies provide protection until the foal is several months old and able to build its own immune system.
As early as six weeks before the expected foaling date, the mare may begin “bagging up”, or developing an udder. Other mares don’t bag up until a couple days before foaling. Daily checking of the mare’s udder is recommended in the last month of gestation. Premature udder development can indicate problems with the placenta.
Signs that a mare is within hours of going into labor include: distended udder, swelling of the vulva, waxing of the teats, teat secretions, and milk leaking.
Mares generally foal at night. The foaling process is divided into three parts:
Preparatory phase: There is contraction of the uterus and dilation of the cervix. Mares may become restless, refuse to eat, walk in circles, look back toward their flank, and switch their tails. These signs often resemble colic. This is the longest stage of foaling and can last anywhere from 30 minutes to six hours. When the mare breaks her water or starts expelling fluid, the first stage of parturition is completed.
Labor: This is the most exciting part of the whole process. Just before a foal is the born, the mare will likely sweat profusely, and when contractions begin the mare can either be standing up or lying down. The mare may get up with part of the foal exposed but will normally lie down to complete the birthing process, provided she is not disturbed by observers.
A foal is on its back until the actual foaling process begins. During labor, the foal then twists inside the mare so that the front legs and head turn over as they exit the mare’s body. The front feet and the muzzle are first to appear! If the foal presents in any other fashion, a veterinarian should be called immediately.
Delivery of the foal should occur within 20-30 minutes of the water breaking. Maiden mares (mares foaling for the first time) are more likely to take about an hour to expel the fetus, and handlers should be ready to assist if it goes much longer than an hour. Mature mares in labor for more than 30 to 45 minutes may also need assistance.
After the foal is born, the mare will continue to lie on her side for another 15 to 20 minutes. This time is important for the mare to rest and for blood flow from the placental tissues to pass into the foal. Handlers will often gently move the foal so that the mare can see it, and even touch it for the first time.
Passage of afterbirth: Once the mares stands, she will begin to nuzzle and lick the foal. This is a critical period as the bond is being established between the dam and foal. A mare can identify her foal within an hour of birth, within smell being the primary recognition factor.
The afterbirth is usually expelled within three hours of birth, and the state of the placenta provides important information about the health of the foal. A retained placenta can cause severe infection in a mare, and aggressive treatment may be required if the placenta is not passed.
Foals should be able sit sternal within five minutes of birth, and stand within an hour of birth. This is always neat to watch as it normally takes several failed attempts for the young life to put all the pieces together and take their first steps.
As soon as the foal is steady on their feet, they should attempt to nurse. Sometimes it takes the foal a few tries to locate the teats and begin suckling. Failure of the passive transfer of maternal antibodies (remember colostrum from paragraph 3 above) puts the foal at significant risk of infectious diseases. IgG (Immuno gamma globulin) levels are measured in the blood of neonatal foals. If IGG levels are low, a they may be tubed with more colostrum or receive plasma.
Foals nurse frequently during the first few weeks of life and as they age, they are introduced to other feedstuffs such as hay and grain. Foals remain close to their mothers in the first few weeks, but by about three months, they spend the majority of their time with other foals. The weaning process takes place about six months of age. It’s time to start growing up, and preparing to be a racehorse!
Miss Part 1? Read it here.
Click here to view photos of each stage of the foaling process.