Another point of confusion rests with the breed of horse being fed.  The phrase “you can’t feed an Arabian like a Thoroughbred” highlights the impact of differing genetics on growth rate and ultimately on the amount of feed the weanling is fed.  The influence of genetics on nutrition is well understood in other farm animals where it is common to have a different feeding program depending on the breed (genetics) of the animal.  In horses, the genetic diversity within a breed is often as big a factor as the genetics between breeds in feeding young horses.  In the American Quarter Horse breed, weanlings bred for halter classes have a far greater capacity for muscle growth and development than weanlings bred for performance classes.  Simply looking at the physical differences between halter horses and reining horses should point out the genetic differences and thus the need for different feeding programs.  Finally, “good old difference of opinion” is a factor in feeding young horses.  Some people like to feed grain to babies; others feel that feeding grain to young horses is the root of all evil.  Although feeding weanlings is confusing, the fact remains that nutrition mistakes (over-feeding or under-feeding) made early in life can lead to structural problems that limit future success potential.       

Creeping Feeding – Preparation for Weaning

One of the more complex management decisions that the horse owner has to make is whether or not to creep feed foals.  Creep feed is feed (usually grain) available to the foal that is not available to the mare.  Creeping feeding has achieved somewhat of a negative connotation with many horse owners.  The term “supplemental feed” is a more accurate term indicating that foals have access to a controlled amount of nutrients in addition to mare’s milk.  The reasons for supplemental feed for the foal are two-fold.  First is the issue of providing nutrients to the foal that may not be in adequate supply in the combination of mare’s milk and pasture/hay.  The 1989 NRC does not give specific feeding recommendations for the suckling foal other than to say that supplemental feed prior to weaning may be desirable in foals nursing mares that are poor milkers.  Recent research, both in the United States and Japan, has indicated that foals require supplemental feed to achieve growth rates desired by today’s horse owners.  These studies revealed that foals not only required supplemental energy, but they also required supplemental protein and minerals. 

Breed differences and the amount of pasture and/or hay consumed will indicate the amount of supplemental energy necessary for a suckling foal to reach industry standards for growth.  In some cases, foals may get enough calories from milk and pasture/hay to achieve adequate growth.  Figure 1 shows the amount of digestible energy a foal would achieve from milk and good quality pasture.  This foal does not require any additional calories, but would require additional mineral fortification.  This represents a common scenario with warm-blood foals.  They get plenty of calories from milk and pasture and typically don’t require supplemental grain to assist in body weight gain.  However, feeding these foals a low-intake (1 lb./foal/day), low-calorie source of vitamins and minerals would ensure the foals are properly fortified with nutrients critical for sound growth without making them obese.  This diet scenario is shown in Figure 2.

A Thoroughbred foal given the same access to pasture and mare’s milk may not be able to achieve industry standards for growth.  Figure 3 shows a diet of milk, pasture and four pounds of a 16% protein fortified grain.  Both the low-intake, low calorie supplement and the 16% grain concentrate satisfy vitamin/mineral needs, the major difference being the 16% grain provides more calories to the growing foal.  So how does one tell if their foal needs four pounds of well-fortified grain concentrate or just one pound of a concentrated protein, vitamin and mineral supplement?  The answer lies in evaluating body condition.  If foals are well conditioned and are gaining an acceptable amount of weight to achieve the foals commercial endpoint on milk plus pasture, choose the low-intake supplement.  On the other hand, if the foal requires the extra calories to keep pace with industry standards feed them the higher-volume, higher-calorie grain concentrate.  An easy way to track foal weight gains is to utilize an equine weight tape or scale.  Both will allow you to check the weight of your foal against normal growth rates for foals of that age and breed.  Normal growth curves can be obtained from the National Research Council or the nutritionists at Performance Horse Nutrition. **May want to include growth data**

The second reason for feeding foals prior to weaning is to teach them to eat the feeds they will survive on once they are weaned.  Introduction of grain and hay will teach the foal to eat these feeds and help prevent post-weaning slumps in growth.  Post-weaning slumps in growth are often followed by surges in growth once the weanling learns to eat.  This slump in growth followed by super rapid growth is thought to be a prime opportunity for the foals to get Developmental Orthopedic Disease (DOD).  DOD is a term used to describe a number of related diseases affecting the maturation of cartilage into bone in young horses.  Clinical manifestations of this disease include physitis (commonly but incorrectly called epiphysitis), osteochondrosis (OCD), cervical malformation (wobbles), contracted tendons and angular limb deformities.  Serious cases of DOD are economically devastating, eventually leaving valuable weanlings essentially worthless due to crippling lameness.      

Example Weanling Diets

          Feeding weanlings can be roughly divided into three broad categories.  These categories are futurity weanlings, weanlings to be sold as weanlings, and weanlings to be kept.  The following discussion will highlight the potential differences in the feeding programs for each type of weanling.

Futurity Weanlings

          A futurity weanling is usually a weanling between four and ten months of age.  These weanlings are of light horse breeding (Quarter Horses, Paints, Appaloosas etc.) shown at halter.  Many weanlings are shown in futurity classes as it is the first opportunity to get young horses seen and promote stallions.  Evaluation of weanlings is based on conformation, size and way of going.  Therefore, it is an advantage for the weanlings to have maximum growth and condition.  To achieve maximum growth and condition, weanlings are often fed large amounts of grain.  It does little good to tell a person raising futurity horses that they are feeding a young horse too much feed.  If they do not maximize growth and condition early on, they will not win a prize come futurity time.  Balancing maximum growth, maturity and condition with sound skeletal development is the challenge of feeding futurity weanlings. 

          Normally weanlings that are going to be prepared for futurities are kept in the barn from the time they are weaned until the time they are shown.  This makes meeting their nutrient requirements easier in some respects since you do not have to account for the variation in pasture nutrient quality.  One important consideration with futurity horses is weaning time.  Weaning time is affected by the month of birth of the foal, the milk production of the mare and the date of the futurity.  Foals born early in the year can remain on the mare longer than foals born in April and May.  This extra time a foal can spend with the mare is often an advantage since the foals will continue to grow in a relatively stress free environment.  Foals that are born late run the risk of having to be weaned early.  If foals are weaned too close to a futurity, it is likely that the weanling will appear pot-bellied due to a nearly unavoidable post-weaning slump.

          The diet for a futurity weanling must be extremely palatable since they are being asked to eat a large volume of feed.  The forage source should be a good mixed (alfalfa x grass) hay or a fine stemmed alfalfa hay.  Nutritionally the mixed hay is preferred because of the better balance (ratio) of calcium to phosphorus.  Hay should be offered to this age weanling at a rate of approximately 9-10 lbs./weanling/day.  The grain portion of a weanling diet is the primary vehicle for delivery of essential nutrients.  Depending on the nutrient content of the hay, the grain will provide the majority of the energy (calories), protein, minerals and vitamins.  Therefore, a grain concentrate designed for a weanling should be fortified with high quality protein, additional calories (from fat) and readily available minerals and vitamins.  Generally, a grain concentrate appropriate for a weanling will contain at least 14% crude protein.  If grass hay is being fed, the grain concentrate will contain between 16 and 18% crude protein.  Many people are afraid to feed young horses too much protein for fear of causing bone problems.  However, mild excesses in protein intake will not cause bone problems.  Instead, imbalances in mineral intake or extremely rapid growth triggered by excess energy intake are likely cause of bone anomalies.  The easiest method to determine if the grain contains all the necessary vitamins and minerals is to read the feed tag and be sure the grain concentrate intended for use in young, growing horses. Grain intakes common for weanlings being prepared for futurities would approach 9 lbs./weanling/day.  Finally, an additional source of dietary fat is a must to provide calories for weight gain and essential fatty acids for hair and skin health.  Vegetable oil and/or high fat stabilized rice bran are good sources of fat for these young horses. 

Many people incorrectly think a halter horse need only be fat to be successful.  In fact, modern futurity weanlings must display muscle tone.  Exercise is the method of choice to achieve muscle toning.  Many methods of providing forced exercise are available, including hand walking, longeing, ponying, and treadmills.  Ponying is becoming increasingly popular with weanlings since the horses are not being asked to constantly turn as is the case with longeing.  If the duration and intensity of exercise are too great for the individual weanling, injury and weight loss can occur.  On the other hand, weanlings confined to stalls with out adequate exercise will posses less bone and muscle mass than exercised weanlings.  Any exercise program should be adjusted to the conformation and body condition of the individual horses.  A single exercise program will not fit every weanling.  Proper feeding and exercise are 2/3 of the puzzle for getting futurity babies to look the part.  The other part of the program is health care and grooming.  Weanlings must be wormed on a regular basis and have the necessary immunizations and grooming to look their best.  An example diet for 6 month-old futurity weanling is shown in figure 4. 

Sale Weanlings

A young horse destined to be sold as a weanling is much easier to feed compared with the futurity weanling.  Weanlings that are being sold usually spend a portion of their day or night confined to stalls with the remainder of the time spent outside where they can graze and exercise.  The combined affect of more time spent grazing and playing in a pasture and less time in a stall translate into fewer digestive problems and weanlings with good muscle tone and bone mass.  Since forage is a large portion of their diet, sales weanlings typically eat fewer pounds of grain in a given day than futurity weanlings.  Most sales weanling would not exceed 6 –7 lbs. of grain concentrate per day.  On the other hand, it is rare for a sales weanling to not require at least some grain.  Even weanlings described as “easy keepers” would require some extra nutrients (calories, protein, vitamins and minerals) provided by the grain concentrate to make themselves presentable for auction.  Dietary fat is typically included in the diets for these weanlings as a means of assisting with hair and skin quality.  A diet for a sales weanling is shown in figure 5.

Weanlings to be Retained

Weanlings that are not going to sales or shows are typically fed in a more conservative manner.  These weanlings do not have to grow at a maximum rate or look their best at a young age.  Instead, we are trying to raise young horses that will be sound athletes.  Generally the best way to assess the impact of the feeding program of these weanlings is through assessment of body condition.  Weanlings should maintain a thrifty appearance in which the horses ribs can not been seen, but can be easily felt.  Monitoring weight along with a good condition scoring system allow for the accurate assessment of quality and quantity of growth.  The amount of grain necessary to maintain a thrifty appearance varies with the factors mentioned in the introduction of this article.  Being able to feed weanlings as individuals and make necessary feeding adjustments is very important.  “Easy-keeping” weanlings should be kept from becoming fat by being fed a low intake, low-calorie source of essential protein, vitamins and minerals.  Figure 6 is an example of this type of feeding program.  On the other hand, weanlings that are big and have a lot of growth potential can consume normal amounts of fortified grain concentrate.  A general rule of thumb for feeding weanlings is 1 lb. of fortified grain per 100 lbs. of body weight, up to a maximum of 6 lbs. per weanling per day.   It is important to remember that foals from various light horse breeds will not weigh the same at a given age.  Further, all young horses do not grow at the same rate or mature at the same time.  Horses need to be fed as individuals.

-Dr. Stephen Duren  M.S. PAS Ph.D. Equine Nutrition and Exercise Physiology, Performance Horse Nutrition