LACTATION places a massive physiological demand on the mare and the majority of owners will be aware of the increased feed requirements of her once she has two to feed – but the actual figures can be staggering.

The time at which nutrient demand is greatest for the mare is during early lactation, or the first two months. During this time a well fed mare will produce the equivalent of 3-4% of her body weight in milk daily. For a 500kg mare that amounts to about 15-20kg of milk!

During a six-month lactation, lactose levels increase over the period whereas protein and fat levels drop. There is a rapid change in these levels during the first month of lactation with more gradual changes during subsequent months.

Total milk output peaks at 31 days and then steadily drops back to nearly half of that by the sixth month. So what does this mean for feeding mare and foal

Lactation feeding

In order to sustain the above level of milk production, the energy requirements of mares in early lactation are double that of barren or early gestation mares.

In fact, nutritionists believe that few horses require more energy – not even the majority of high performance horses! So the primary goal of feeding the nursing mare should be to maintain optimal body condition.

Luckily, most mares foal just as the spring grass is coming through, which will naturally improve her energy and protein intake. Energy and crude protein requirements increase by 75-100%.

Requirements for macro-minerals, especially calcium and phosphorus, also increase by three-fold and 2.5-fold, respectively and grass will not provide this. This is why it is advisable to feed your mare a formulated stud feed, balancer or mineral mix (depending on condition score) during this period to ensure that these extra requirements are met.

Due to this drain on body reserves during lactation, it is crucial that the mare is in at least moderate body condition prior to foaling with a good condition score 3-3.5 (ribs can be felt but not seen) or you will have problems with condition loss during lactation.

Mares in poor body condition have inadequate energy stores to produce ample milk and this can have consequences on the growth and development of her foal. Conversely, obese mares also seem to produce less milk and like the thin mare her offspring tend to lag behind their peers.

Feeding under-weight mares

Most mares experience weight loss during lactation which, if she is fleshy to start with, isn't a problem. Some mares, like some hardworking horses, are unable to maintain their weight on typical portions of hay, pasture and feed.

The usual rules of not feeding more than 2kg in any one meal must still be adhered to, which may mean your mare requires fed more than the usual 2-3 times per day. You may have to increase the energy density of her ration by selecting a higher energy feed (higher oil content) or by supplementing with a high fat additive (either liquid oil or one of the many extruded products that are on the market e.g. Build and Glow or Outshine).

Also ensure that she is being fed the best quality forage and pasture available. These mostly thoroughbred types may require more careful assessment and consideration and the use of specially formulated stud/breeding diets, designed for thoroughbreds is advised, as is the advice of an appropriate nutritionist.

The good 'doer'

All mares are different and those who are good doers (native types etc) will not need much extra feeding throughout the whole process and every effort must be made not to allow obesity at any stage of the reproductive cycle.

Hay and grass should make up the majority of the mare's diet. They do, however, require vitamins, minerals and trace elements throughout pregnancy and lactation and a balancer pellet may be appropriate for the last three months of gestation as well as the first two months of lactation.

At least a higher specification supplement (in particular calcium and phosphorus) should be fed.

The foal

By two-three months old, the mare's milk will no longer fulfil the foal's requirements and this is why it is advisable to start creep feeding the foal at about three months old.

It will probably be picking at his mother's feed by then but requirements are quite different from the dam's at that age and it is best to purchase a specific foal feed.

Trials show that foals who are creep fed have a 10% improvement in daily gain and lose less weight at weaning; as their digestive systems are used to the feed prior to weaning.

The foals also experience fewer problems later in life due to the fact that they exhibit a steady growth and there is no spurt of compensatory growth after the post-weaning slump, which can sometimes cause many growth disorders as the year goes on.

In general, creep fed foals have a far less stressful weaning with little or no interruption in growth.

At weaning for

foal and mare

At weaning, your foal should be used to eating his own concentrate feed. It is advisable that any concentrate that the mare is being fed is tapered off gradually as weaning approaches.

Recommendations are that all mares, regardless of body condition, have the concentrate portion of their diet withdrawn for 1-2 weeks post weaning.

They should still be given access to us much grass or forage as they please and they still require vitamins and minerals, but this break from concentrates should mean that milk production will stop fairly quickly.

Once the mare has dried up the focus should then return to weight management of the mare.

By Dr Vicki Glasgow Equine nutritionist for Harbro