If a foal has trouble adapting to weaning then weight gains will be low and it may actually lose weight. After a period with depressed weight gains, the foal will eventually adjust to a forage and concentrate diet.
Foals possess the potential for very rapid compensatory growth, so the Teagasc team advises breeders to resist the temptation to greatly increase the foal's concentrate intake because it could result in weight gain of more than 1.5kg/day, which in turn may aggravate or result in cases of DOD.
Here's their advice on how to manage feeding from birth to two years old:
Birth to three months
Milk is the natural diet of a foal and during pregnancy the unborn animal accumulates stores of minerals to support it after birth and counteract the lower than ideal levels in the mare's milk.
Providing a balanced diet for the mare during pregnancy enables the foal to build up sufficient stores.
Birth to three months of age is the period of most rapid growth in the foal, as it gains about 1kg/day while suckling its dam.
However, some mares do not milk well and will not be able to provide sufficient energy for the foal to grow. In such cases, it is advisable to offer a creep feed to the foal.
About three to five weeks into lactation, the mineral levels in the mare's milk drop between 40-60pc so an alternative source of minerals with a low energy content should be provided.
Three to six months
From three months of age onwards, foals start to develop the ability to digest forage and grain, so the transition from a milk-based diet to cereal-based feeds can begin.
The feed should be low in calories so that weight is put on due to quality growth, instead of fat. From three to six months of age, foals gain weight at a rate of 0.65-0.9kg/day.
Approximately six weeks before weaning, creep feeding at a restricted rate of 0.5-0.75kg/100kg bodyweight of an 18pc crude protein stud nut or growing foal concentrate should begin. This serves to smooth out the growth curve and introduce the foal to its post-weaning feeding regime.
By weaning time, foals should be on full daily concentrate rations and good-quality forage or grazing, which will help to avoid post-weaning stress. After weaning, the concentrate feeding rate can be increased to 2-3kg/day.
DOD can be caused when developing bones are traumatised due to the foal being overweight.
Therefore, breeders need to monitor each foal individually and, if necessary, tailor the diet to restrict foals that are becoming too heavy. Exercise is essential for bone strength and will also combat weight, so turnout is essential for foals.
Six to 12 months
From six to 12 months of age, the foal's weight gain is about 0.5-0.75kg/day.
The amount of feed necessary to support growth will normally decrease as the foal gets older and the rate of growth slows.
The exact diet will depend on individual requirements. It is important to consider that overweight foals are at risk of having health problems, so a low-calorie, high-nutrient balancer may be required.
The level of concentrate fed should be 1-1.5kg/100kg bodyweight of a 16-18pc crude protein ration.
Good quality forage should be available ad-lib and concentrates can be reduced with grass growth and cut out completely as the yearlings have access to good pasture.
12 to 24 months
At this point in their life, yearlings may be gaining between 0.3-0.65kg/day in weight.
Grass is usually sufficient to keep most heavy foals in good condition, but a supply of vitamins and minerals is important for the development of internal tissues, hair, hoof and skin.
During the animal's yearling winter, feed about 4-5kg of concentrate/day, consisting of a 14-16pc crude protein ration with forage available ad-lib.
The level of concentrates can be reduced if there is a good supply of top-quality forage.
Two years to maturity
Any growth that occurs after the animal is two years of age will be very slow.
Under normal circumstances of good grazing conditions, these horses require no concentrates unless they are being prepared for sale or show or during ill health.
Winter feeding of concentrates may or may not be necessary, depending on the individual animal, housing, weather conditions and overall health.