Matching your horse’s diet to his workload involves supplying the calories and nutrients he needs to maintain the desired body condition and fuel his work whilst keeping the diet balanced at all times.
Modern compound feeds are all formulated to be fed at calculated levels, according to work intensity, alongside forage of a recognised “average” nutritional quality, to supply calories and nutrients that are lacking in that forage and so provide a fully balanced diet. The nutritional content of forage will vary according to type and time of year but typically it can be expected to provide calories, from fermentable fibre and soluble carbohydrates, which for some horses will be sufficient for condition and work, plus other nutrients, including some protein, vitamins and minerals, whose levels vary and ideally need supplementing whatever the workload.
A horse has a limited appetite so, in theory, can physically only consume the equivalent of 2 to 2.5% of his bodyweight in food, whether forage or concentrate feed, per day. So, as his energy and nutrient requirements go up, his total diet must be more energy and nutrient dense to supply “more per mouthful”. Choosing more nutritious and digestible forage will help but is not always sufficient so the concentrate feed becomes the focus, with different ones developed to provide different amounts of calories and nutrients per scoop. Once the correct one is chosen to suit the horse’s requirements, it then has to be fed according to the manufacturer’s recommendations to ensure a fully balanced diet.
Maintaining Forage Levels
With a greater amount of calories and nutrients coming from concentrate feed, it is possible that the horse will lose some of his appetite for forage but ideally should still have access to forage ad lib, to satisfy his need to chew and to maintain a healthy digestive system. (Recommended minimum for maintaining overall health and function of the digestive system is not less than the equivalent of 1% of the horse’s bodyweight).
The psychological and physiological benefits of this approach far out weigh any which suggest that forage intake should be limited for horses in intense work in an attempt to minimise bulky fibre sitting in the horse’s digestive system. The only instance when forage intake really requires management is for the specially good-doer or overweight horse, when a calorie-controlled diet is required but not at the expense of fibre intake. Chosen forages should be as low in calories as possible, so stalky, coarser hay over soft, leafy haylage, and may need feeding in small-holed haynets to make a smaller amount last longer.
Essential Nutritional Support
Whatever level of work a horse is doing, he still needs essential quality protein, vitamins and minerals to support general health and well-being, including tissue integrity, muscle tone and healthy hoof growth. Indeed, ensuring a horse receives these nutrients at all times, even when at rest, helps his body lay down reserves (not fat) and repair and rebuild any injured tissue. For this reason balancers are particularly useful as they supply all these essential nutrients with no additional calories so ensure a balanced diet at times when recommended amounts of even a low energy feed would provide too many calories. They are fed in small quantities and may be given as the only concentrate feed alongside forage or added to reduced amounts of mixes or cubes to top up nutrient (not calorie) levels and maintain a balanced diet.
Matching Feed to Workload
When looking at mixes and cubes, the idea is to match the levels of energy and nutrients they provide to your horse’s requirements. The table below gives a guide to the energy levels provided by feeds (expressed as Mega Joules per kilogramme (MJ/kg) of Digestible Energy (DE) and to which workloads they are best suited.
Levels of other nutrients contained by feeds are also matched to the intended workload, with lower energy feeds supplying correspondingly lower amounts of vitamins and minerals than high energy feeds. Reputable feed manufacturers will also select ingredients for the quality of nutrients they supply and their availability to the horse; there is no point including high levels of a certain nutrient if it is of poor quality and the horse’s body is unable to absorb and utilise it efficiently.
As workload increases therefore, the type and energy level of feed may need changing accordingly to deliver additional calories and nutrients in a manageable quantity. Different horses have different metabolisms though so, whilst a horse’s requirement for calories (energy) will depend both on workload and body condition, “good-doers” generally have lower requirements whatever the workload. Their requirement for protein, vitamins and minerals however, remains directly related to workload so a good-doer in hard work will still need elevated nutritional support, just fewer calories than a “poorer-doer”. For these horses, a lower energy feed or reduced amount of a higher energy feed, may be best to suit calorie requirements but both would need topping up with a balancer to provide essential nutrients for a balanced diet.
Always divide the total concentrate ration into as many small meals as possible to avoid overloading the digestive system. Any changes should also be made gradually – reducing the existing feed and correspondingly increasing the new feed - and it’s entirely possible that, for some horses, a combination of feeds of different energy levels gives the best results. Either way, manufacturers’ recommended feeding levels should be adhered to, to ensure a horse is not missing out, whilst no obligation advice is available from trained nutritionists via feed company helplines for those who have any doubts.