Feeding Weanling HorsesBy Dr. Peter Huntington · February 27, 2012
The weanling has similar nutrient requirements to the yearling, but eats less, so if a weanling is to achieve maximum growth rates the nutrients must be more concentrated. Weanlings have a greater risk of developmental orthopedic diseases (DOD) if fed excessive energy. Thus, the feeding program for weanlings presents a challenge.
The weanling has the stress of being taken from its dam, mixing with a new group of young horses, and sorting out the social order, often at a time of year when weather conditions are adverse. Nonetheless, if it is to be a future racehorse or futurity prospect, it is likely very important that it continue to grow rapidly to be ready for the annual weanling or yearling sales or shows.
The first factor to consider is the age of weaning. The mare’s milk production peaks at two months after foaling, after which there is an increasing gap between the foal’s needs and what the milk can supply. A foal can be weaned any time after four months of age, and a recent study showed that weaning at that age was less stressful than at six months old, when stress was judged by a growth setback at weaning.
In general, five months of age is thought to be an ideal time to wean. However, many factors may indicate a need for adjustment of the timing of weaning. Weaning may need to occur earlier in some cases. If the foal is doing too well (growing too rapidly, getting too fat) or has signs of DOD or conformation defects (e.g., getting erect in the pasterns), it may need to be weaned as early as three months so that nutrient intake can be carefully controlled. Similarly, foals that are failing to thrive as expected may either be weaned early to supply a more controlled diet to overcome deficits that might be due to poor milk production by the mare. Conversely, a foal who has been ill and isn’t doing as well as desired may be left with the mare for a longer period of time. Another factor is how well the mare is doing, and early weaning may be needed if the mare is losing condition by continuing to feed an older foal.
One factor that has a big influence on the growth of weanlings is familiarity with hard feed prior to weaning. If the mares are not being fed any supplements or are being fed a ration different from what the weanlings will receive, it is a good idea to creep-feed your weanlings. This will provide for supplemental caloric and nutrient intake as well as acclimate the foal to the ration it will consume as a weanling, reducing another potential source of stress at weaning time. To achieve the optimum growth rate, the average six-month-old, 250-kg (550-lb) weanling growing at 0.9 kg (2 lb) per day will need 2.5-3 kg (5-6.6 lb) of a weanling feed per day, which equates to 1% of body weight.
Because the recently weaned foal may have a restricted appetite, it is important that the feed is palatable. Sweet feeds are more palatable than pellets or extruded feeds and may encourage weanlings to eat more. Processing of the barley and corn in sweet feeds will increase the energy content. Weanlings will need to be fed twice daily, but you need to allow for variation in intake; for example, if you have eight weanlings in a paddock, provide them with nine servings, either in bins or a trough. If you have an older babysitter horse in the group, allow two servings for it. In this way you can help to ensure that everyone receives a full serving despite the inevitable shuffling around that comes with feeding horses in a group. Matching up the weanlings by age will allow you to vary the intake appropriately.
The quality and quantity of pasture available will determine the amount of supplemental forage the weanling needs. Hay should be provided if pasture is not available or the weanlings are kept off pasture for any reason. The weanling’s protein requirements can be met by a combination of young, green pasture and an appropriate grain mix. It is not essential to feed forage as chaff, but it does increase the safety of feeding grain to a group of weanlings, in which case the amount of chaff should be in proportion to the amount of grain. If pasture is scarce or dry, the weanlings will need supplementary high-quality lucerne (alfalfa) or clover hay/chaff to provide higher levels of energy, protein, and calcium than grass hay or oaten chaff. A grass or hay diet alone will be deficient in the necessary minerals and vitamins.
The advent of presale radiographs has focused attention on DOD and other bone problems in young horses. Although underfeeding leads to reduced growth and/or bone problems, overfeeding causes rapid growth which can lead to metabolic bone disease and poor conformation. Putting extra weight on a young skeleton is undesirable because the bones are not yet sufficiently developed to carry the heavy weight. If you feed high-energy (i.e., high-grain) diets to achieve maximal growth you will increase the risk of DOD, but if you do not, you are unlikely to meet the market expectations for growth and condition. However, it is important to remember that nutrition is only one of the risk factors involved in DOD. The aim of weanling feeding is optimum growth with minimal DOD.
With the correct feed and appropriate intake there is no need for added supplements, which may in fact create nutritional imbalances. Key nutrients such as amino acids, calcium, phosphorus, copper, zinc, manganese, and vitamin E should be provided by the hard feed. Weanlings that are too heavy or have early signs of DOD should not receive the traditional grain-based feed, but should have their amino acid and mineral needs supplied by a low-calorie balancer pellet as a supplement to forage. Weanlings that are not destined for the sales or show ring can be fed more conservatively because they do not have to grow at a maximum rate or look their best at a young age.
The best assessment of the feeding program is the body condition score of the weanling. Weanlings should maintain a thrifty appearance in which the ribs can either be just seen or can be easily felt. The amount of feed necessary to maintain a thrifty appearance will vary according to the needs of the individual weanling and the quality and quantity of the available forage. Feed weanlings as individuals and make necessary feeding adjustments rather than feeding them as a group. If the weanling needs extra energy, this can often be supplied as fat or high-quality forage.