Horse Breeding: Colostrum for Foals
Make sure your newborn foal gets the best chance at a healthy first year.
By Dr. Thomas Lenz for The American Quarter Horse Journal | August 11, 2016
As you probably know, colostrum is the thick, yellow, honey-like first milk produced by a mare just prior to foaling. It differs tremendously from the white milk she will produce throughout the rest of her lactation.
Why It's Important
Unlike that of a human, the mare's placenta does not allow the transfer of antibodies (protective proteins that fight off infection) directly from her bloodstream to her foal's during pregnancy. As a result, foals are born with little or no protection against infectious disease. However, the mare does pass along antibodies in her colostrum that will protect the foal during the first few months of its life, until its own immune system matures and is capable of fighting disease on its own. Foals that do not receive adequate colostrum suffer from a syndrome called failure of passive transfer (FPT), which is estimated to affect up to 25 percent of newborn foals and predisposes them to life-threatening diseases.
We've known for years that foals should ingest roughly 2 quarts of colostrum during the first three hours of life to ensure maximum antibody transfer and protection. At roughly eight hours after birth, the foal's intestinal lining begins to "close," and its ability to absorb antibodies decreases gradually until it ceases antibody absorption completely after 18-24 hours.
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Because the average foal takes in only about a half pint of liquid per feeding, it is crucial that it is up and nursing as soon as possible. If a foal cannot stand to nurse, it is always a good idea to milk the mare and give the foal colostrum via a bottle or bucket. In some cases, it might be necessary for a veterinarian to provide the colostrum via a stomach tube.
Failure of passive transfer can develop for a number of reasons. The mare might not produce adequate quantities of colostrum. This is especially true in mares older than 15 years of age or on fescue pastures. The mare also can drip milk for a few days prior to foaling and deplete her store of colostrum.
Mares that drip milk (premature lactation) for more than 24 hours pre-foaling will seldom provide the foal with adequate levels of colostrum. Foals can also suffer from FPT if they fail to nurse, are premature or suffer from disease. Fortunately, there are a number of instruments and tests your veterinarian can use to determine if the mare's colostrum is of good quality and contains adequate amounts of antibodies.
Blood samples collected from the foal 12-24 hours after birth will also determine if the foal has ingested and absorbed adequate amounts of colostrum. If the test determines the foal hasn't received adequate amounts of colostrum, it can be provided antibodies via commercially available plasma administered intravenously. As in all medical problems, the best defense is preparation. Visit with your veterinarian several weeks prior to the anticipated foaling date to establish an action plan in the event something goes wrong.
Besides providing life-protecting antibodies, colostrum is also an important energy source. The foal's internal energy source is very low, and glycogen (sugar) stores present at birth provide only two hours of energy to the unfed newborn foal. Fat stores are also very low.
Therefore, the newborn foal is at risk for malnutrition and subsequent weakness from the very start unless it receives nourishment. One good feeding of colostrum provides up to 18 hours of adequate blood glucose and energy to sustain the foal. Colostrum also contains a protein called lactoferrin that sequesters iron and prevents bacterial colonization of the intestinal tract, which in turn prevents foal diarrhea. In addition, colostrum contains several components that aid the foal's white blood cells in fighting off invading bacteria.
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Infectious diseases enter the foal's body through the umbilical cord, the lungs or the intestinal tract. Because the intestinal tract is the most common entry point in the young foal, it's easy to appreciate the importance of colostrum's protective mechanisms.
Because of the obvious importance of colostrum to the newborn foal, many broodmare farms and veterinary clinics maintain stores of frozen colostrum to be used in an emergency. To bank colostrum for future use, it is usually possible to collect at least a half pint of colostrum from a mare without depriving her own foal. Of course, the colostrum should be collected immediately after the foal first nurses and should be tested to ensure its quality. Your local equine veterinarian is the best source of information on specific procedures and recommendations to ensure your newborn foals get a healthy start in life.