NUTRITION of the breeding stallion is a key consideration for all stallion owners and handlers, particularly at this time of year. Breeding stallions are often difficult to maintain at optimal body condition; some become too light at the height of the breeding season, while others maintain body condition very easily and can be liable to get too heavy when fed energy-rich concentrates. By providing a carefully balanced diet and monitoring weight regularly, a stallion’s body condition score can be kept at an optimal level all year long.

For the stallion, the year can be divided into two basic phases, breeding season and the off-season.

The breeding season lasts five months for the majority of stallions. In the northern hemisphere, the breeding season commences in mid-February and ends in June for the majority of thoroughbred stallions. For non-thoroughbred stallions the breeding season is not as restricted with timelines as artificial insemination can take place but often these stallions are still kept in work while also providing semen for breeding stations. National Hunt stallions will cover mares later into the summer months if demand for their services is there.

In the southern hemisphere, the schedule is flipped, with the breeding season beginning on August 1st and finishing in late January. Some thoroughbred stallions are dual hemisphere, servicing a book of mares in the northern hemisphere early in the year and a separate group in the southern hemisphere later in the year.

Properly nourished

Regardless of the number of mares bred, stallions must be properly nourished to perform their jobs successfully. From a nutritional standpoint, the act of breeding can loosely be classified as work. According to ‘Nutrient Requirements of Horses’, produced by the National Research Council, breeding stallions expend nearly the same amount of energy as performance horses in light work. This may be slightly elevated when stallions are bred multiple times a day. Several large studs breed their stallions three times daily during the peak breeding season. Extremely popular stallions could cover even four mares per day. Stallions also vary greatly in the amount of exercise they give themselves; some are naturally more sedentary than others. During breeding season, nervous stallions may burn valuable calories walking the fence when turned out, box-walking, pacing, and weaving. Breeding may not be the only work certain stallions perform. Some continue to be ridden and trained while performing stud duties.

In these instances, energy requirements would be higher again. You may consider a high calorie but slow releasing energy diet for this type of stallion to ensure that he remains rideable while ‘double jobbing’.

Body weight

The breeding stallion requires, above all else, a balanced diet. First and foremost, stallions should be provided with high-quality forage, consuming a recommended 1.5% of their body weight in forage dry matter per day or ad lib forage for those that need support in maintaining condition. The minimum amount of hay offered should be 1% of body weight. Depending upon the time of year, good quality grass may supply some or all of the stallion’s forage needs. During the breeding season, the addition of energy-dense feeds, usually concentrates, may be necessary to satisfy calorie requirements for the increased workload of breeding. Products such as Gain stud cubes and Gain stud mix are ideal for breeding stallions and should be fed at the recommend feeding rates, which is expressed as a quantity per 100kg body weight.

Small meal sizes are important in terms of helping to avoid digestive upsets. Fortified concentrates will contain the vitamins and minerals necessary for optimal nutrition. As with all horses, stallions should have access to a salt lick while stabled. If the stallion is consuming a well-balanced diet, the addition of other vitamins and minerals will not enhance fertility.

Ideal weight

As breeding season unfolds, stallions should be in moderate to fleshy body condition, which means the stallion’s ribs should be palpable but not visible and minimal fat may be deposited along the withers, behind the shoulder, and around the tail-head. Once an ideal weight has been achieved, every attempt should be made to keep the stallion’s weight at this level. This can be achieved by weighing the horse periodically, usually weekly. A weight tape can be used but a scales will be a more accurate tool. Keep a record of the horses’ weight and track this over time. This will be very useful working with veterinarians or nutritionists when working on routine queries such as worming or seeking any alterations to the diet.

A very thin stallion may not have the energy stores necessary to carry on through an arduous breeding season without his performance suffering. Stallions become too thin when they use more calories than they consume. To encourage weight gain, provide free-choice access to high-quality forage (usually pasture and/or grass hay) some additional high quality chopped alfalfa will also be useful for this type and supplement with the recommended amount of a fortified concentrate.

If a stallion fails to gain weight on this basic diet, a fat supplement such as stabilised rice bran (eg. Infinity) or linseed oil can be included in the daily diet. With the energy density of these supplements, stallions will consume far more calories than it is possible to obtain from feeding safe amounts of common concentrates. Their coats will also benefit from the higher oil intake, which will enhance the stallion’s appearance.

Another common reason for thinness among breeding stallions is reduced appetite. The anxiety surrounding the breeding shed may affect some stallions. It is important to monitor this with stallions that are in their first season. More common than underfeeding, however, is overfeeding.

Obesity predisposes stallions to laminitis, soundness problems (particularly of the hind legs, which is reflective of the strain placed on them during breeding), and possibly heart attacks, often caused by aortal rupture. Extremely overweight stallions are thought to have lowered libido. If obesity is a problem, stallions should have restricted access to pastures, especially in the spring, and only enough concentrate to ensure the stallion’s vitamin and mineral requirements are met.

An alternate way to satisfy these requirements is to feed a highly fortified low calorie balancer such as Gain StudCare 32 at a rate of 1kg per day. During the off-season, stallions may be maintained on high-quality forage alone.

If a stallion requires concentrate, feed only enough to maintain optimal body condition.

Joanne Hurley M.Agr.Sc has worked in the equine nutrition industry for over 20 years and is head of Equine at Gain Equine Nutrition. If you are a stallion owner and wish to get some tailored nutritional advice please contact Joanne on or our customer services centre on 0818 321 321