As cooler weather approaches, now is the time to determine your horse's weight and decide if you need to bulk up or lighten the load. Some horses have difficulty gaining weight during the hot, humid mid, summer weather and can even lose weight due to aggravation from insects. There are a few easy ways to determine your horse's weight and body condition score (BCS).
Weight tapes can be bought at the local farm or tack shop; however, if you don't have one handy a simple measuring tape will suffice. Use bailing twine or a cloth measuring tape to measure your horse's heart girth measurement. This is done by placing the tape over the withers and around the girth of the horse. Next, measure the body length, from the point of the shoulder to the point of the buttocks. If your horse is an adult, then divide by 330 (in place of X in the formula), if it is a weanling use 280 and if it is a yearling use 301.
Plug those measurements into this formula to determine your horse's weight:
WEIGHT = (Heart girth) x (Heart girth) x (Body length)
Example:Heart girth = 70 inches; Body length = 78 inches; Adult horse use 330
Weight = (70) x (70) x (78) = 1158 pounds
Using the estimated weight of your horse can help determine if he or she is gaining or losing weight over the winter.
The next step is determining the body condition score of your horse. This score takes into account more than just the weight of the horse and can help an owner determine if their horse is at an ideal weight. The scale ranges from 1 to 9, grade 1 representing an emaciated animal and grade 9 representing an obese one. The score takes into account common areas of fat deposits. These areas may go unnoticed when looking at the overall condition of the horse. The diagram at right shows common areas that are evaluated to determine a BCS. It is important to feel these areas on your horse as simply looking will not give the most accurate results. Also, remember that during winter months a thicker coat can disguise horses that are losing weight. Don't be fooled by a thick, woolly winter coat.
The chart below is a good guide for helping owners and veterinarians determine the body condition score of a horse. Before going into winter an ideal BCS for any horse is around a grade 6. Horses that are in hard work or competing are often ideally a grade 5. Once an ideal BCS is obtained, determining the weight of your horse can help you maintain that condition score throughout all of the seasons.
You've determined your horse's weight and body condition score, now how much should you feed it?
Typical horses should be fed approximately 2% of their body weight. Using the number you obtained from the calculation or weight tape multiply it by 0.02. This will give you the number of pounds of hay the horse needs per day. This is often divided into 2-3 feeding per day. The next step is to weigh a flake of hay. This can be accomplished with a bathroom scale or fishing scale. Simply weigh yourself without a flake of hay and then weigh yourself again holding the hay, next subtract the difference. Take the number of pounds of hay the horse needs per day divided by the number of pounds each flake weighs to determine the number of flakes of hay each horse should get per day. These measurements may seem tedious; however, not all bales are created equal and can make a huge difference in the amount of food your horse is actually getting each day.
Here is an example:
A 1000lb horse should be fed 20 pounds of hay/ day (1000 x 0.02 = 20)
Bale A: Each flake weighs 5lbs
Bale B: Each flake weight 2.5lbs
This same horse should be being fed 4 flakes/day of bale A and 8 flakes/day of bale B.
As with all things, observing your horse's weight is the most important thing. Use these guidelines as a start and then increase or decrease the amount of hay depending on how much weight is being gained or lost. Supplementing a horse's diet with grain or concentrate feed will increase the amount of calories the horse is getting. This is a great way to help keep your horse at a healthy weight, or give a horse that is training or showing the extra calories it needs. Concentrate feeds are not, however, a requirement for every horse. It is completely healthy for a horse to just be fed grass hay, especially if the horse gains weight easily.
We often recommend a vitamin and mineral supplement for these horses. The key to finding a good supplement for a horse is to make sure that it has high concentrations of vitamins and minerals and is low in calories. Some grass balancers require feeding up to a whole pound to get all the required nutrients. This will add a hefty amount of calories to the horse's diet. Most important is finding a unique feeding regimen for your horse that maintains a healthy body condition score and weight over the colder months. If your horse is underweight, these cooler months before winter sets in are a great time to gradually try adding more concentrated feeds and fat supplements. If your horse is overweight, you may think the extra insulation will help, however, it can lead to more metabolic, hormonal, and lameness related problems in the future. Ensuring a long life for your horse involves helping them maintain a good, healthy weight.
If you would like to have a more in-depth analysis of your hay including protein and nutrient content, local feed mills and the University of Minnesota Extension services offer hay analysis at reasonable prices.
Talk to your veterinarian about a specific feeding and supplement plan for your horse before the snow flies. It can make a huge difference on your horse's overall health and your pocketbook. With just a few simple tools you can keep a close eye on how your horse's weight is doing this winter.
Chart of Body Scores: