A weight bridge is far more accurate and should be used instead of a tape if available. Condition scoring is the best form of recording weight changes. Weigh your horse every 2 weeks and plot the changes on a graph. The requirement is between 1.5 to 3% of its body weight, averaging at 2.5%. Use the following equation to determine how much you should feed your horse each day: BodyWeight/100x2.5=Total Daily Ration Do you want to keep your horse at the level it is already at (maintenance diet)? Do you want to reduce the horse’s weight because of health issues (reduction diet)? Or, do you want to increase your horse’s body weight due to a past illness or because your horse is underweight?  The best strategy to use when developing a feeding plan for your horse is to feed based on the desired weight, rather than the current weight. e.g. A horse is underweight and weighs 300kg. If the horse’s ideal weight is 400kg, don't feed 2.5% of 300kg. Feed 2.5% of 400kg. Use the same strategy for an overweight horse. Feed based on the desired weight, and not current, meaning you will actually be feeding less that the overweight amount, meaning, a reduction of waistline for your horse. Different forage have different amounts of DE (digestible energy) this depends on the type of forage (grass, haylage, hay, oat straw) and the type of grass (rye, timothy, cocksfoot or orchard grass). For grazing the time of year also affect the DE. Spring grass has a high level while winter grazing is very poor. For preserved grass the “cut” affects the DE. Early cut grass is higher in DE than late cut grass. Oat Straw is very low in DE. The best way to find out the nutritious in your forage is to have it analyzed. Some horses are prone to heating up (becoming over excited and spooky). Feeding these horses slow-release energy (fiber and oil) will help, this is the safest form of energy and causes the least amount of health problems. Other horses are lazy and lack “sparkle”. Feeding fast-release energy (starch found in cereals/grains like oats and...

TL;DR in Vietnamese:
Đo khối lượng cơ thể của ngựa bằng thước dây hoặc cầu đo khối lượng (cân dành cho ngựa). Tính tổng nhu cầu trong chế độ ăn uống hằng ngày của ngựa (thức ăn gia súc và bột). Xác định cách thức tăng cân đối với ngựa. Kiểm soát mức năng lượng trong thức ăn gia súc bằng cách cho ăn nhiều loại khác nhau hoặc trộn chung nhiều loại. Xác định loại năng lượng dành cho ngựa. Tham khảo ý kiến chuyên gia trong trường hợp không xác định được lượng thức ăn dành cho ngựa.