Feeding the Young Horse

Published in Horses and People Magazine

By Mariette van den Berg, BAppSc. (Hons), MSc (Equine nutrition)
Photos by Albert Akkerman

Sound development

The growth of a new born foal is exceptional. A healthy foal grows quickly, at 6 months the foal already attained 40-50% of his mature weight and 75-80% of his mature height. The foal must receive adequate amounts of energy, protein, minerals and vitamins to facilitate this growth and achieve full genetic potential. Proper feed management supports quality and controlled growth in foals and reduces future risks of developing bone and joint problems. Sound development is important for the longevity and athletic performance of young horses.

Bone and joint disorders, commonly known as Developmental orthopaedic disease (DOD), are a major concern of horse breeders. DOD in young horses can arise between birth and 1 ½  years of age. The most common bone and joint disorders that affect young horses are osteochondritis dissecans (OCD), physitis, angular limb deformities and contracted tendons. Enlargements and deformities of the ankles, knees and hocks and “pulling up” in the pasterns (contracted tendons) are common symptoms of DOD. Genetic predisposition, rapid growth, strenuous or restrictive exercise, trauma and poor nutrition are factors that can contribute to the development of DOD. A combination of these factors may cause DOD.

Poor nutrition can increase the risk of DOD in growing horses. Feeding excess energy or not supplying adequate amounts of nutrients (minerals and energy) for normal development can lead to unsteady growth, which may cause bone and joint abnormalities.

In addition, some horse breeds may be genetically programmed to grow faster than other.  Therefore, it is important to meet individual nutritional needs and maintain moderate growth and body condition (Henneke body condition score of 5) to reduce the development of DOD. Monitoring the weight and wither height of the foal on a regular basis gives a good indication of the growth rate and helps with formulating a proper diet to manage optimal development and body condition.

Nursing foals

To develop into a strong and healthy athlete the foal should consume 15 to 25% of his body weight in milk daily. The new born foal should drink the first 48 hrs after birth colostrum from his dam. Colostrum is the first milk of the mare and contains not only energy and protein but also essential immunoglobulins. When the foal is born his immune system is not fully developed to cope with pathogens from the environment. The immunoglobulins in the colostrum provide immunity against bacterial and infectious diseases during first weeks of life. The ingested immunoglobulins also provide gut protection to cope better with dietary changes once the foal starts eating solid feeds.

At two week of age the foal will try to nibble grass or feedstuffs from his mother. The mare’s milk production will decline after 3-4 months of lactation and the foal must start eating solid feeds to meet its daily nutrient requirements. Creep feeding can start at 8 to 12 weeks of age. The digestive system of foal is only small and these anatomical limitations prevents the foal from being able to utilize large amounts of bulky feeds low in quality. Therefore, the foal must be fed concentrated sources of energy, protein, minerals and vitamins to meet nutritional requirements. In particular, the protein quality and quantity is important. Provide your foal with a high quality creep feed (15-20% protein) and feed small amounts twice a day. Increase creep feed gradually to 0.5-1.0 kg per 100 kg body weight per day. Breeders that feed grains must complement the diet with a protein supplement. Soybean meal and dried milk products are high quality protein sources.

Weanlings

Most breeders start weaning their foals at 5 or 6 months of age. Weaning is a stressful period for the foal and may cause a decrease in the foal’s growth performance (post weaning slumps). Insufficient intake of nutrients may increase the risk of bone and joint problems. In particular, between 5 and 12 months of age higher risks of DOD are observed. The foal must eat sufficient creep/concentrate and quality forage (hay and/or fresh pasture) before weaning to minimize the risk of post weaning slumps.

Weaned foals should be offered high quality pasture, lucerne or grass hay. In addition, they should have excess to all the high quality forages they can consume. Weanlings must also be supplemented with a concentrate or grain mixture. Always balance nutrients of forages with concentrates to provide adequate amounts of protein and minerals. Weanlings can be offered daily a total diet of concentrates to forages in a 70:30 ratio.  Concentrates (15-18% protein) should be fed at 1.0 kg per 100 kg body weight per day.  A protein, mineral and vitamin supplement must be added to grain mixtures to correct nutrient deficiencies.  Feeding weanlings small amounts of concentrate 3 to 4 times a day will improve nutrient absorption and reduce growth slumps.

Weanlings should not be overfed. Managing the growth of the weanling is important because excessive weight gain may cause also bone abnormalities. The weaned foal should be maintained in a moderate body condition (score of 5).

Weanlings need to be turned out daily to allow all the voluntary exercise they want. Exercise is good for strengthening the bones and it improves athletic ability.

Yearlings

At 12 months of age a young horse already achieved 85-90% of its mature height and 60-65% of its mature weight. At this stage the growth rate will slow down, but young horses will continue to grow until they are approximately 4-6 years old.

Yearlings can be fed less concentrated rations and more bulky feeds because their digestive system has grown. Yearlings can meet the majority of their nutrient requirements from high quality forages (pasture or legume hay).Yearlings that receive poor quality forages or are exercised need to be supplemented with a concentrate. Provide a feed mix that contains protein (10-12%), high fermentable fibre and fat. Up to 10% fat can be added to the diet to safely increase the energy density. It is advised to feed yearlings in training adequate amounts of energy, protein and minerals. In particular, the calcium, phosphorus and magnesium  requirements of  exercised yearlings increase. Yearlings can be fed a balanced ration at 65:35 ratio of concentrate to forages. A higher ratio (70:30 ratio) should be fed if yearling are fed low quality forages or are exercised. Intense training should be gradually introduced because excessive forced exercise can increase the risk of DOD. A proper training program with adequate recovery time for bone remodelling assist with keeping your young horse fit and healthy.

A selection of the daily nutrient requirements of weanling and yearling are described in table 1. These requirements are recommendations of the National Research Council (NRC, 2007).

Table 1. Selection of daily nutrient requirements for growing horses
(per 100kg mature body weight)

Summary

Young horses must receive adequate amounts of nutrients to support sound growth and achieve full athletic potential. Feeding high quality forages and concentrated sources of energy, protein, trace minerals and minerals are essential for optimal development. Young horses should be fed for a moderate rate of growth and be maintained in a moderate body condition. Avoid overfeeding young horses because excess weight and a rapid rate of growth can place more stress on the bones and joints. In addition, some horse breeds have  genetic predisposition for skeletal defects and overfeeding can cause rapid early development which may lead to DOD.

Poor nutrition may increase the risk of DOD in young horses. However, there is not one single diet that cures all bone and joint problems in young horses. A sound feeding program starts off with feeding the broodmare properly throughout pregnancy and lactation.

This is followed by proper feeding management of the young horse during first 2 years of life. An individual well-balanced diet and regularly monitoring of the growth rate, body condition and general appearance assist with reducing the development of DOD in young growing horses.

“Feeding the young horse” (part 4) was the last article of the series on breeding horses.

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