The most common mistake I come across as a nutritionist out in the field is an incorrectly balanced diet, especially for horses who are maintaining their weight. They are often receiving enough energy and protein, but not enough minerals.
The best way to feed your horse is to offer them appropriate forage in appropriate amounts, then add a product to balance that forage i.e. to make up for the shortages of essential nutrients. Forage could be pasture grass, hay, haylage, straw, hydroponic grass or short chop. You should choose lower energy forage for good doers (horses and ponies who maintain their weight easily) and higher energy for thin horses or hard working horses. Feeding ad lib (free choice) is ideal, but not possible for any who put on excess weight on such a regime.
Choosing very low energy forage – or soaking for 12 hours – allows you to feed an overweight horse closer to their appetite, rather than restricting under 1.5% bodyweight in dry matter (per 24 hours), which is unhealthy. Choosing higher energy forage for hard working horses is healthier for them, and reduces reliance on concentrate feed.
UK grass by its very nature is short of essential minerals for horses, and after preservation into hay or haylage, is short of vitamins as well. Pasture grass supplies plenty of vitamins, and good levels of protein. It is usually high in energy and good pasture should be restricted for most horses apart from those with poor appetites, breeding stock and those who need more condition. Hay can vary in its energy and protein content depending on when it was cut – i.e. how mature is was when harvested – whether or not it was rained on during harvesting and the species of grass it contains. To be sure, have it analysed.
Forage alone is not a balanced diet, even if it does meet energy and protein requirements. All horses should be fed a multi-vitamin and mineral supplement, whether that is in a supplement form, a pelleted balancer, or within a compound feed (coarse mix or nuts). You must feed the full recommended amount to ensure enough vitamins and minerals so if your horse does not need extra condition, then feed a supplement or balancer, not less of a concentrate compound feed.
If you are soaking your hay for over 10 hours to help your horse lose weight or to reduce sugar and fructan intake, you need to supplement protein as well as vitamins and minerals, so a balancer is the best choice. If your horse is maintaining their weight and condition on forage, then simply add a multi-vitamin and mineral supplement in a handful of plain chaff, unmolassed sugar beet or any feed of your choice.
Working horses do not necessarily require concentrate compound feed, although their forage needs to be chosen carefully to ensure it supplies enough energy. Researchers in Sweden have shown that trotting Standardbreds grow and perform well on forage-only diets balanced with micronutrients.
Consider carefully whether or not your choice of product balances your horse’s forage, and if you are feeding less than the full recommended amount of a compound feed with good forage, then change to a multi-vitamin and mineral supplement instead.