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An important and exciting time for an owner, check out these articles for some helpful information.


Developing the Growth of the Young Horse Safely


Nutritional Support of the Young Horse

The growth of young horses (particularly between weaning and two years old), has received much attention from the veterinary scientists and some clear results have come from this research. It is accepted that in growing horses, energy and protein are the most important factors in the diet.

When horses are being bred and developed to be sold as young animals, or to be considered for a competitive career at a young age (eg racing), then there is a tendency to maximise feed, particularly protein to create rapid growth to maximise the size and the bulked up look of the horse earlier. This is called maximal growth and is undesirable, optimal growth is correct and beneficial to the long term prospect of the horse, it will still reach its genetically determined size. However overdoing the amount of feed and particularly if it is unbalanced in the ratio of fat, carbohydrates and protein will have detrimental effects on the physiology of the horse.

High energy diets without the full nutrient support may result in horses gaining weight faster but the risk is that the bones are not developing at the same rate and so result in bone developmental problems that will affect the usefulness of the horse. Young horses need mineral supplementation and care with the amounts and ratios of minerals and vitamins is necessary. Read our article ‘What Supplements Does Your Horse Really Need Each Day’ for full details and amounts.

Fat and forage must be part of the diet in correct ratio. Forage (fibre) should never be less than 30% by weight of total feed intake, preferably higher, up to 50% or more. Much will be provided by pasture, but since the quality of pasture can be variable and the actual known intake difficult to assess, it is necessary to provide quality fibre with the daily feeds. Fat can be sourced from pasture, from direct addition of a vegetable oil or from meal feed such as copra meal and soyabean meal, or from rice bran. The ratio in total should not exceed 10% and if the horse has a relatively high grain intake there is a possibility that they can become too fat and so the fat intake should be reduced.

Dietary proteins do perform a foremost role in the health and growth of animals, protein requirements of the growing foal are a function of the amino acid requirements. Amino acids are the building blocks of protein, the quality of the protein is determined by its amino acid composition. It is the quality not the quantity of the protein in the diet that regulates how well the horse grows and functions, a young horse will need 14-16% crude protein as a ratio of its feed intake. For more on protein read our article ‘Protein- What, Why, How Much’.

Lysine is the first limiting amino acid in the horse and threonine the second limiting amino acid. A limiting amino acid can be described as one that if not present will prevent protein from being made even if other amino acids are present in adequate quantities. There is much science proving that protein quality can be improved by supplementing with the first and second limiting amino acids.

Increasing protein quality rather than quantity has the advantage of more efficient utilisation by the horses, as it is not good practice to create excessive inputs of energy and  protein due to the risk of extreme growth rates and creation of developmental disorders.

Negative Effects of too Much Protein on the Young Horse

Too much protein creates a tendency to overheat, blow and sweat excessively, produce high levels of ammonia in the urine. Potential blood insulin levels become too high, negative bone disorders can occur. Heat production from higher levels of protein may interfere with exercise by attenuating fatigue. Increased acidity will interfere with glycolysis and muscle fibre contraction. Urea levels in the blood increase leading to greater urea excretion into the gut which increases the risk of gut disturbances and enterotoxaemia. Increases in blood ammonia creating nerve irritability edgy behaviour, plus disturbances in carbohydrate metabolism, ammonia smells in the bedding, this can create respiratory issues from the stabled horse. E.A OTT research (Energy, Protein and Amino Acid Requirements for Growth of Young Horses) shows that reduction of concentrate protein and subsequently the feed intake of the animal, decreases the blood insulin concentrations which may be advantageous in helping minimise bone development problems. He goes on to suggest that protein concentrate can be reduced when the diet is proportionately supplemented with lysine and still support maximum growth response. Research data such as Growth of Thoroughbreds fed a low protein supplement fortified with lysine and threonine W.B. Staniar et al, concludes that fortifying the diet with lysine and threonine, improves protein quality and enables full realisation of genetic potential for growth, while raising horses on forages with a lower protein concentration and acid (P.M. Graham-Thiers et al).

In conclusion, if the diet is supplemented with lysine and threonine, dietary protein can be reduced and in doing so will reduce negative effects of too much protein, without loss of growth or performance.

Vetpro Lysine-T contains the essential amino acids lysine and threonine in a correct balance with correct effective dose levels, in conjunction with a yeast extract and yeast culture. Yeast in horse diets has been shown to enhance the activity of fibre digesting bacteria which increases nutrient availability and absorption. Yeast also stabilises the hindgut to help maintain a healthy bacterial population allowing optimum digestion to take place.

Bone Development of the Young Horse

Nutrition is important in maximizing bone density. Bone mineralisation begins during the last three months of pregnancy. At this point the foetal bones are simply cartilage models of the adult bones. The skeleton of the newborn foal contains only 17% of the adult bone mineral content.

Skeletal growth is rapid during the first 12 months. A study of growth rates in young thoroughbreds showed that at 6 months of age a horse can reach 84% of its mature height but only 46% of its mature weight. At 12 months it can attain 94% of its height and 65% of its weight. By 22 months it has virtually stopped growing in height (97%) and has usually reached 90% of its mature weight. Skeletal growth therefore occurs faster than weight gain. Other studies have followed total bone mineral content (BMC) during the same growth period. At 6 months of age bone mineralisation is 68% complete, by 12 months it has increased to 76%. Maximum BMC is not reached until a horse is 6 years old.   

Calcium and phosphorus are the main minerals found in bone. Daily requirements are dependent on growth rate. A six month old weanling gaining 0.65kg/day requires approximately 38g calcium and 25g phosphorus/day. A 12 month old yearling gaining 0.5kg/day requires around 45g calcium and 30g phosphorus. Lucerne hay is the best feed source of calcium containing around 12g/kg while grains are the best source of phosphorus (3.0g/kg). Bran contains high levels of phosphorus but only 20% is available for absorption.

The ratio of calcium to phosphorous is just as important. Diets should contain ratios of between 3:1 and 1:1 calcium: phosphorous. Studies have shown that high ratios of around 6:1 fed over a long period resulted in reduced bone density. Inverse ratios can also have a detrimental effect. These can occur on high grain/low lucerne diets. Studies have shown that feeding extra calcium has no effect on bone density.

Magnesium is essential for the formation of the collagen matrix as well as bone mineralization. Around 60% of the magnesium in the body is found in bone tissue. Human studies have shown a positive correlation between bone mineral density and dietary magnesium. Low magnesium is associated with reduced activity by osteoblasts and osteoclasts, the cells involved in bone remodeling. Good feed sources are lucerne (3.0g/kg) and soyabean-meal (2.7g/kg).

Copper, zinc and boron are trace minerals that play an important part in bone development. Studies have shown that copper supplementation of mares and foals can play an important part in skeletal development. Zinc is essential for bone and cartilage formation. It can interfere with the uptake of copper consequently high dietary levels are detrimental to skeletal development. Boron is a trace element that up until recently has received little attention. Human research indicates that boron aids the uptake of calcium and magnesium into bone as well as increasing vitamin D3 levels, important for bone mineral metabolism.

Silicon is one of the most common elements on earth and is essential for normal body function. Most of the silicon found in nature is in a form of sand and is unable to be absorbed by the body. Plants can take silicon up from the soil consequently the forage and grains that horses consume contain small amounts. Silicon is involved in the formation of the collagen matrix as well as bone mineralisation. Experiments on chickens fed silicon deficient diets resulted in lower bone collagen levels, resulting in abnormal bone growth.

The same series of experiments also showed that silicon supplementation increased the rate of bone mineralization as well as increasing the glycosaminoglycan levels in cartilage, important in the prevention and treatment of degenerative joint disease.

Studies carried out at the University of Texas demonstrated the importance of silicon in maximizing bone density in young racehorses. In these studies horses on silicon supplemented diets were able to train and race for longer and sustained less bone injuries than non supplemented horses. This was attributed to an overall improvement in bone density. It was noted that silicon supplementation had no effect on growth rate therefore was not connected with any risk of growth related diseases like OCD.

The studies also showed that if an absorbable form of silicon is given to lactating broodmares the levels in the milk increase which results in more silicon available to the foal. Interestingly human studies on milk mineral composition have shown that zinc, copper, iron and silicon are the trace elements found in the greatest concentrations during early lactation. As lactation advances, zinc, copper and iron levels decrease while silicon stays the same.

Dietary mineral supplementation along with careful design of training programmes will result in improved bone density and in turn, improved skeletal durability. Young horses will able to stay in training for longer without the interruptions that bone injuries can cause.


Growth of thoroughbreds fed a low-protein supplement fortified with lysine and threonine

W. B. Staniar, D. S. Kronfeld, J. A. Wilson, L. A. Lawrence, W. L. Cooper and P. A.

Harris J Anim Sci 2001. 79:2143-2151 PROTEIN AND AMINO ACIDS EDGAR

A. OTT University of Florida, Gainesville, FL

Growth of Thoroughbreds fed Different Levels of Protein and Supplemented with Lysine

and Threonine W B Staniar

Lysine Supplementation of Diets for Yearling Horses E. A. Ott, R. L. Asquith and J. P.

FeasterJ ANIM SCI 1981, 53:1496-1503.

The results of these Influence of Energy and Protein Content of the Concentrate and

Restricting Concentrate Intake on Growth and Development of Weanling Horses E. A.

Ott, PAS and J. Kivipelto professional animal scientist 302-311

Amino acid supplementation improves muscle mass in aged and young horses P. M.

Graham-Thiers and D. S. Kronfeld J Anim Sci 2005. 83:2783-2788.

Dietary protein influences acid-base responses to repeated sprints PATRICIA M. GRAHAM-THIERS, D. S. KRONFELD and

K. A. KLINE Virginia Polytechnic Institute and State University, Blacksburg, Virginia 2406 1-0606, USA.

Influence of Temperature Stress on the Energy & Protein metabolism and requirements of the working horse. E. A Ott Dept

Animal Sciences University of Florida

The effect of supplemental lysine and threonine on growth and development of yearling horses P M Graham, E A Ott, J H

Brendemuhl and S H Ten Broeck J ANIM SCI 1994, 72:380-386.

Care of the Orphan Foal


It is tragic when the mare dies during or soon after foaling. However with veterinary assistance and good care it is possible to successfully raise an orphan foal. Here are some notes that may be of assistance to you.

First Needs

Firstly clean and dry the foal and keep warm, cover if necessary from extreme weather conditions. The foal should be on its feet within the first hour of birth. First concern to deal with is whether the foal has suckled and therefore received colostrum. Colostrum is absolutely necessary and, if the mare has provided none, should be fed in a sterilised bottle within the first hour but no longer than 4 hours from birth. This is the first milk a mare produces and contains antibodies which protect the foal from viruses, bacteria and diseases in the early part of its life. It may be possible to milk the mare if death was not from disease or infection; this can be done for up to four hours after death. Otherwise contact a local stud or your veterinarian to obtain some frozen colostrums. If the foal will not suckle the bottle then call the veterinarian who will need to stomach tube the colostrum. All foals should receive a minimum of 1500 – 2000mLs (2500 mLs for larger foals) of colostrum within the first 8 hours after birth. If using frozen colostrum, thaw only in warm (38C) water. It is important to have your veterinarian check the foal’s IgG levels at 24 hours to confirm adequate uptake of colostrum antibodies. Do not give water or any Foalmilk or substitute until after the colostrums have been given.

Call the local studs or a foster mare association or even the local radio station to see if a foster mare can be arranged, one who has just lost a foal. If a mare is not available then a substitute for mare’s milk must be fed to the foal.

Check that the foal passes meconium within 8 hours of birth. Natural colostrum is very laxative so artificially fed foals need to be watched closely. Meconium is the dark pellet first droppings, if after 8-12 hours and you are in doubt as to whether it has passed, or if the foal is looking distressed and continues to strain (even though some may have passed ), call the veterinarian without hesitation.

Keep a watch on the temperature, pulse and respiration each day. At birth the pulse is 80 beats per minute rising to 140, then reducing to 100 which is the norm. Temperature is 37.5 degrees C, respiration 30-40 per minute. Any changes should be noted and a call to the veterinarian made.

If diarrhoea occurs (scouring), take the temperature three times daily and notify the veterinarian if it increases. Scouring may be due to too large a feed at any one time, or too concentrated. It can be due to infection also and the veterinarian will be needed. From 3 weeks of age introduce hay and hard feed, there are premixed foal feeds available, or you can make up one from the details given in the Vetpro Foalmilk instruction leaflet. Make the introduction of hard feed gradual.

What and How to Feed

Only use a specifically formulated mare’s milk replacer, NB a cow’s milk or lamb’s milk replacer is not a suitable substitute for foals. The different ratio’s of fat, sugar and protein in these milk replacers is not the same as mare’s milk replacer (Foalmilk) and will cause disturbances to the digestive process of the foal and they do not provide the correct amount of fat, sugar and protein to enable the foal to thrive well. In some cases scouring can occur which is debilitating for the foal.

All bottles, buckets and any equipment used with mixing and feeding must be absolutely clean and kept in a sterile fluid. Sterilising tablets are included with the pack, along with a teat. Mix the powder with water as per the instructions provided. If the foal is having difficulty accepting the bottle, put the foal’s head under your armpit and keep your hand under it’s chin, keep the bottle angled slightly up to prevent air being sucked in. Remember orphan foals are high risk when it comes to gastric ulcers and post-partum infections so a foal that has trouble taking a bottle may in fact suffering from one of these problems. If in doubt call your veterinarian.

Once any opportunity for a foster mare has passed start introducing the foal to drinking Foalmilk from a bucket. This should have happened after three weeks. Water should always be available also.

How Much Does a Foal Need

During the first 2 days a normal foal will suckle from its mother 6-8 times an hour throughout the day. Depending on its birth weight it will drink approximately 300mls/hour or 6-7 litres a day. To mimic the natural loading of the stomach it is recommended that orphan foals receive frequent small feeds (24 per 24 hours) especially during the first 48 hours. This hourly bottle feeding should be continued for the first 3- 4 days. From day 4 onwards, two hourly bottle feeds are acceptable. By day 7 the foal should be able to go through the night on 4 hourly feeds (although this is not ideal for the foal, it does allow you to get some sleep). From 3 weeks of age an orphan foal can be bucket fed 6 times a day (4 hourly).

During the first 48 hours a foal should drink 10-15% of its bodyweight per day. In practical terms this means that a foal weighing 50kg at birth should receive 5-7.5 litres over a 24 hour period, this would be for a foal with an expectation of an average mature size of around 500 Kg, say 16.1 hh.

From 2 days of age the same foal should drink 20% of its bodyweight from which it should gain between 1-1.5kg bodyweight per day. This means that an extra 200-300mls of Foalmilk Replacer should be fed each day to allow for the increase in bodyweight.

During the first week no more than 500mls should be given at any one feed as over-feeding may cause diarrhoea.

Foal birth weights and growth rates can vary considerably between breeds so it is important to weigh your foal to accurately determine the volume of milk required over the first 3 days. Once you know your foal’s bodyweight, the volume of milk required for a 24 hour period can be calculated.

Example 50kg Foal

Day 1: Bottle feed 300mls of colostrum every hour for the first 12 hours followed by 300mls of Foalmilk Replacer every hour for the remaining 12 hours.

Day 2: Bottle feed 300mls of Foalmilk Replacer every hour (total 7.2 litres).

Day 3 Onwards: To calculate the daily Foalmilk Replacer requirement, weigh your foal and feed 20% of its body weight at the recommended frequency. Increase Foalmilk Replacer by 200-300mls per day to allow for daily weight gain so for example after 7 days the total becomes 8-8.5 litres per day for the average foal

From 3 weeks of age, orphan foals will start to eat hay and hard feed. There are pre-mixed foal feeds available, or you can make up one from the details in the Vetpro Foalmilk instruction leaflet. Make the introduction of hard feed gradually; reducing the intake of the liquid Foalmilk until by 12 weeks it is weaned off it. Foals will eat hard feed as required; any uneaten feed should be discarded each day.

A pony foal weighing 25kg at 48 hours should receive up to 5 litres of Foalmilk from which it should gain around 0.5-0.75kg/day. It should receive an extra 100-150mls each day to allow for the increase in bodyweight.

Warmblood and draft type foals increase the above volumes of Foalmilk and hard feed by 20-30% at the same frequency.

Further Hints on Rearing an Orphan Foal

– Orphan foals often get bored so it is helpful to rear them with a companion pony.

– If the weather is bad put a cover on for the first few weeks. Allow as much exercise and fresh air as possible.

– Do not allow foals to become ‘cute’ with biting, rearing or striking behaviour.

– Always allow free access to water.

– Bottle feeding increases the human-foal bonding process which is not advantageous. Many hand reared foals become too confident and develop serious behavioural problems later in life with some becoming impossible to handle. For this reason it is important to start bucket feeding as soon as possible. Maintain discipline and do not see the foal as a pet, remember a bump from cute foal may be not a problem but later at 500 kg can be dangerous.

Preparation for Birth- Who gives the signal


Eleven months, eleven days have passed quickly. It didn’t seem long ago that the stud master had phoned to say that your mare had been served. Nor did it seem that long since you paid the vet’s bill for the 42 day pregnancy scan.

The time had passed quickly alright; you had followed the check-list you wrote to the letter. You had taken the vet’s advice on feeding, increasing the energy and mineral content of the diet during the final three months of pregnancy. You had even bought a spare set of batteries for your torch and a film for you camera.

Yes, there was no doubt you were prepared and ready as you would ever be for the birth of the foal. Now the waiting game had begun; night after night of interrupted sleep, getting out of bed every 2 hours to check on the mare. After five nights nothing had happened. You started to feel a bit weary; your boss had noticed you yawning at work. How long do I have to keep this up for, you ask yourself.

So who decides when the birth process should start? What are the signs of parturition and are there ways of accurately predicting when foaling will take place?

In the year 600 BC, Hippocrates stated that it was the foal that controlled the time of birth. It took scientists until the early 1960’s to gather enough evidence to support his claim. Through studying pregnancies in sheep and cows, they found that foetuses with brain and pituitary gland deformities, had longer gestation periods than normal. Possibly there was some chemical interaction missing between the foetus and the mother that caused the pregnancy to continue past full term.

The pituitary gland, located at the base of the brain, is the main endocrine gland in the body. In response to incoming messages from the brain, it produces hormones that are released into the circulation, targeting other endocrine glands throughout the body. Each hormone is able to instruct the gland to produce its own hormones which in turn are released back into the circulation to act on various organs and muscles.

The main endocrine gland under pituitary control is the adrenal gland, located just behind the kidney. The pituitary gland produces Adrenocorticotropin (ACTH ) which targets the adrenal gland, instructing it to release Cortisol.

Scientists have been able to demonstrate a steady rise in the level of foetal cortisol as foaling approaches. This increase appears to be the signal from the foetus that it is fully mature and ready for birth.

Because the foetus and the mare share the same circulation, the foetal cortisol passes into the mare, triggering a chain of biochemical events that starts the birth process.

So it appears the foal will decide what day it is born, where as the mare will decide the time of day.

The signs of preparation for foaling are easily recognisable. Approximately 10-14 days beforehand, the pelvic muscles and ligaments start to soften and relax. This is particularly noticeable between the tail-head and the vulva.

Development of the udder or ‘bagging up’ is most obvious sign that parturition is approaching. The final size of the udder can vary between mares so size should not be used on its own to predict the time of foaling. The fluid that can be expressed from the udder (pre-colostrum) changes in colour and consistency as foaling approaches from a clear watery fluid to a thick yellow-cream colour. As it dries, it forms beads on the ends of the teats, commonly known as waxing. This usually occurs 12 to 48 hours prior to foaling. It is a fairly reliable sign but it can vary between mares. Some will not start waxing until hours before, others may not wax up at all but instead drip milk for 3 to 4 days beforehand.

By measuring either the calcium, sodium or potassium levels in the pre-colostrum, the time of foaling can be determined.

The calcium levels are assessed using the test strips that are used for measuring water hardness. The strips consist of 5 zones of increasing sensitivity for both calcium and magnesium. An increase in calcium causes a colour change on the strip. Testing should be carried out on a daily basis. When 4 out of the 5 zones have changed colour there is a 80% probability that the mare will foal within 12 hours. When all 5 zones have changed, the probability increases to 95%.

Measuring the sodium and potassium levels in the colostrum is more involved as it requires laboratory analysis. As foaling approaches, the sodium level begins to fall rapidly while the potassium level rises. At the time they cross over, foaling will occur within 12 hours.One useful piece of equipment well worth investing in is a foaling alarm. These are battery driven devices that are strapped to the mare’s halter and are activated when they are rotated through a 90 degree angle, which in most cases is when a mare lies down. As late pregnant mares prefer to rest standing, they are a reliable indicator that foaling is about to begin.

Mares are notorious for having their foals at night, usually 10 minutes after they were last checked. Making sure you are present for the birth is important so that any problems are attended to immediately.

Whether you chose to employ these methods depends on what value you place on your sleep. I would recommend using the calcium test strips and if you can borrow or hire a foaling alarm, I would suggest using one of them as well; both are time and money well spent.

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