Paul Hart and Heartbreak Hill
(Photo : Suzanne Boswell)

NUTRITIONAL BALANCE IN HORSES

In our series of articles regarding nutrition, condition, performance and the economics of nutrition, we cover a number of topics from the correct body condition for your horse’s performance level to ensuring maximum value from your feeding regimen.

Nutritional Balance
Nutritional management plays a key role in maintaining maximum performance and productivity of horses.

The amount of fat on a horse’s body affects many physiological functions, such as reproductive efficiency and work tolerance. The balance between energy intake and energy expenditure is reflected in a horse’s body condition.

Body condition scoring, can be easily adapted and utilized by all owners to manage the proper timing and the amount and type of supplemental feed needed to maximize performance. Body Condition Scoring (BCS) is a classification system used to determine relative fatness or body condition of horses. This system was developed by Don Henneke PhD and is an assessment of the amount of body fat covering certain skeletal landmarks on the body, such as the point of the hip and buttocks, ribs and spine.

Best Condition

Horses are ranked on a scale of 1 to 9, with 1 being poor and 9 being extremely fat.

Horses should be maintained at condition scores of 5-7 for optimum health and performance. Optimum BCS for working horses is 5-6, and optimum BCS for broodmares is 6-7. The difference in the optimum scores is that reproductive efficiency is better when broodmares are maintained at scores of 6-7. Broodmares that have foaled need some fat stores due to the high nutritional requirements of lactation and recovery from foaling. It is more difficult to put needed weight on a lactating broodmare versus keeping the broodmare in optimum body condition.

The type and level of activity that your horse performs will govern the best condition score. Race horses, eventers, endurance horses and polo ponies should be maintained at a score around 4+ - 5. Show jumpers, dressage horses and show ponies should be maintained around 6-7, again depending on the level of competition and their fitness.

Horses maintained at BCS of lower than 4 may suffer from decreased immunity, impaired reproductive efficiency, and lower work tolerance.

Energy deficiency is a major cause of fatigue. As well as limiting performance, fatigue in muscles increases the reliance on tendons, ligaments and joints – predisposing these to injury and breakdowns.

Maintaining horses at BCS of 8-9 is not economically justified and predisposes them to colic, laminitis, and founder. Overly fat horses also have poorer reproductive performance and decreased work performance.

Condition Scoring
There are nine areas throughout the body that should be assessed:

1) Neck 

2) Withers
3) Shoulder

4) The area directly behind the elbow

5) Topline

6) Ribs

7) Tail head
8) Point of hip

9) Point of buttock

Each area should be appraised and scored individually and then the scores averaged to produce a final overall score. You need to look at the total horse and take into account individual differences. Some horses can be quite plump and yet still look a little ribby, so the overall score should look at areas other than just those ribs. Other horses can have quite a bit of fat cover, but because of funny conformation through the croup, look thin in just that one area. Be sure to look at all the areas, then form a general overall score based on individual areas of observation.

Some of the observation points (such as through the hindquarters or around the tail head) are also areas occupied by muscle, manual palpation and a little practice will easily differentiate between fat and muscle. Horses with a gut full of hay may look very rounded at first glance, but the prominence of the skeleton will not change upon closer inspection. Likewise, a dehydrated horse will appear tucked-up and long through the underline, but prominence of the landmarks will not significantly change.

Skeletal landmarks can be hidden by a furry winter coat, dirt, lighting or just the way the horse is standing. Hold your hand flat, fingers together, and feel for the reference points. Then walk around the horse and see if your observations are consistent from the other side as well.

The descriptions for the individual categories are as follows:

Condition Score 1: Emaciated: Bony structures of neck, shoulders and withers are easily noticeable. Spinous processes, along the ribs, topline, point of hip and point of buttock all project prominently, with an obvious ridge down the back. Individual vertebrae may be identifiable. There is significant space between inner buttocks. The animal is extremely emaciated; no fatty tissue can be felt.

Condition Score 2: Very Thin: Bony structures of the neck, shoulders and withers are faintly discernible. Spinous processes, ribs, topline, point of hip and buttock are prominent. Noticeable space between inner buttocks. Animal is emaciated.

Condition Score 3: Thin: Neck, withers and shoulder are accentuated, but not obviously thin. Tail head is prominent. Slight fat cover over ribs, but still easily discernible. Spinous processes, point of hip and point of buttock are rounded, but easily discernible. Inner buttocks are slightly filled in, but without noticeable deposition of fatty tissue.

Condition Score 4: Moderately Thin: Neck, withers and shoulders are not obviously thin. Ribs are faintly discernible. Point of hips and buttocks are not visually discernible. Fat can be felt around the tail head, prominence somewhat dependent upon conformation. There is a slight ridge along the top line, especially over the loins and hindquarters.

Condition Score 5: Moderate: Neck, withers and shoulder appear rounded and blend smoothly into the body. Ribs cannot be seen but are easily felt. Back is flat along the top line. Fat around tail head is beginning to feel spongy. Slight amount of discernible fat deposited between buttocks.

Condition Score 6: Moderately Fleshy: Fat beginning to be deposited along the neck, withers and shoulders. Fat over the ribs beginning to feel spongy, ribs cannot easily be felt. Fat around tail head feels soft. May be slight positive crease along the top line.

Score of 7-Fleshy: May have crease down back; individual ribs can be felt, but noticeable filling between ribs with fat; fat around tail head soft; fat deposited along withers behind shoulders, and along neck.

Score of 8-Fat: Crease down back; difficult to feel ribs; fat around tail head very soft; area along withers filled with fat; area behind shoulder filled with fat noticeable thickening of neck; fat deposited along inner thighs.

Score of 9-Extremely Fat: Obvious crease down back; patchy fat appearing over ribs; bulging fat around tail head, along withers, behind shoulders, and along neck; fat along inner thigh may rub together; flank filled with fat.

For Better Health and Performance, follow these Key Management suggestions :

• Feed according to class of horse and body condition.

• Consider age, weight, activity level. Older horses and poor doers or thinner horses will require more feed.

• Provide unlimited access to clean, fresh water.

• Maximize forage consumption.

• Forage should be a major component of the feeding programme.

• Feed good-quality hay, free of mould and dust.

• Feed a minimum of 1.5% of the horse’s body weight daily as forage.

Horses should be fed a total of 2-3 % of their body weight, so if feeding 1.5% hay one should be feeding the equivalent in concentrate. It is preferable to have the ratio at 65:35 - Roughage to concentrate. As the work-load increases so the concentrate can be increased slightly.

• Measure feed by weight, not by volume

• All concentrate feeds do not weigh the same.

• Limit concentrates to 2.5kg per meal.

• Make feed changes gradually over a 7-10 day period.

• Manage feeding times/rates.

• Feed a minimum of 2-3 meals/day for stalled horses.

• Monitor daily consumption of feeds.

Hay quality is as important as forage quantity. Hay should have a crude protein content of 7% or higher on an as-fed basis. Hay with less protein tends to be over-mature and have too much indigestible fibre. As plants mature, their digestibility and nutrient content decline.
It is better and cheaper to feed higher quality hay.
Cheaper hay is often unfertilised and the nutrient content is very poor.

Concentrates and Protein: Quantity or Quality
The quality or amino acid composition of the protein in the diet is important. Of the 22 amino acids required by horses, 10 must be supplied in the diet and are thus called essential amino acids.

Muscle development, the ability to repair and rebuild muscles after work and protein losses in sweat creates a need for high quality, highly digestible protein.

It is generally accepted that lysine is the first-limiting amino acid, followed by methionine and perhaps threonine. It follows then that a diet containing sufficient total protein but which is low in lysine will make the balance of the protein unavailable for effective utilization.

Vitamins and mineral levels need to be balanced for feed intake. The vitamin and mineral packs in commercial feeds are really the difference between a good feed and a great one.

A nutrient dense feed like the Vuma range ensures that your horse gets everything it needs from one bag, without the need for adding anything.

Feeds and Heat Production
Metabolism of feeds produces body heat. Metabolism of forage results in the greatest amount of heat, with grains resulting in intermediate heat production and fats the least heat production. Therefore, in winter, it makes sense to increase the forage. Pasture growth slows down considerably in the cold weather and hay becomes more essential to fill the gap, it also helps to keep horses warm.

The overall health of the horse relies quite heavily on the health of the hind gut microbial population. An additional benefit is the mechanics of breakdown of hay which is almost entirely accomplished by the hind gut microbes, and because the process is relatively energy efficient, a large amount of heat is produced. This effectively serves to keep the horse warm from the inside. It is essential to allow unlimited access to good quality hay over the cold months.

Since the feed value of summer pastures decreases quite substantially over the cold months, it is worth supplementing concentrates with a high-energy product like oil. Oil is highly digestible in the small intestine and as such is a good source of "cool" energy.  Using oil will help to minimize behavioural problems associated with high carbohydrate diets and it provides nearly two-and-a-half times the energy of the equivalent weight carbohydrate. The benefits of omega 3 oils include decreased blood lipid concentrations, increased membrane elasticity, increased insulin sensitivity and regulated inflammatory response.

Looking after the system

Teeth
Sharp edges on teeth make chewing difficult so the horse will swallow larger particles of food, resulting in choke in some cases, and reducing the efficiency of the digestion process. The horse may also waste food by dropping it from his mouth or "quidding".
Horses’ teeth should be checked every 6 months or at least annually in some cases.

Worms
Worm damage results in scar tissue which can accumulate over a number of years, reducing the area available for the absorption of nutrients and making it difficult for the horse to maintain its weight and condition. Regular worming assists in promoting good condition throughout the horse's life.
Apart from weight loss, other signs of worm infestation can also include dull hair coat, lethargy, colic, tail rubbing, coughing and summer sores.

De-worming should be done every 8 – 12 weeks, rotating between active ingredients.

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