Page 104 - Speedhorse April 2021

VETERINARY VIEWS
Maintaining Body Condition... as a general rule...
How much a horse improves in per- formance related to fat supplementation depends on many factors – type, intensity and duration of exercise, type of fuel being burned in working muscle (anaerobic vs. anaerobic work), other components of the diet (fiber, protein, and carbohydrates) and the total amount of intake and fat levels. Adding fat to the diet will not make a slow horse faster but may keep a fast horse run- ning faster for longer.
MAINTAINING BODY CONDITION
Fat is an excellent source of calories for
the difficult keeper. Horses can only consume about 1 1⁄2–2 1⁄2 percent of their body weight each day, so it is often hard to pack in enough groceries, particularly to a horse in rigor-
ous work. To compensate for added physical demands, a horse needs a source of concen- trated calories. As a general rule, at least 60% of a horse’s daily diet should be in the form of forage, such as hay and/or pasture. That leaves 40% of the diet that may be offered as concen- trated calorie feed. Historically, concentrated calories relied on grain sugars and starches, with their attendant problems, such as obesity, laminitis, gastric ulcers, colic, and intractable behavior. But, by supplementing with fat prod- ucts, grain can be eliminated altogether or at least cut back to a manageable amount. As an example, including 5–10% fat in the total daily diet can cut concentrates back by 25% while the horse still maintains optimal body condi- tion. For every pound of fat fed, equivalent to 2 cups of oil, the concentrate portion of the diet may be reduced by 1.25 pounds.
Most horses see benefits with from 1⁄4 – 1 lb. of fat per day. How much fat is supplemented depends largely on what other components of the diet are fed and how well they support the level of performance desired, as well as the level and intensity of work.
WHAT KIND OF FAT?
Although horses don’t have a gall blad- der, the equine liver is able to synthesize
bile salts and excrete bile. A horse’s digestive system is geared towards continuous feed- ing, rather than a couple of big meals a day.
... at least 60% of a horse’s daily diet should be in the form of forage, such as hay and/or pasture.
as an energy source. Individual horses and their ability to utilize fat for work varies due to dif- ferences in muscle fiber types. Training affects recruitment of different muscle fiber types. Aerobic training for 90 days or more has been shown to result in hypertrophy (enlargement) of Type-1 (slow-twitch) muscle fibers and no change in Type-2 (fast-twitch) fibers. It’s not that more fibers are made; it’s just that they get bigger. So, specificity of exercise is important in training muscles to do the job you want them to do. The more highly trained the muscles and the more improved their ability to oxidize fat, the greater the benefits achieved from adapta- tion to dietary fat supplementation.
Fat supplementation also helps a horse to recover more quickly from anaerobic work
due to the metabolic adaptation of utilizing
fats at lower intensity work; this allows muscle glycogen to be replenished more quickly. Horses engaged in anaerobic work and also adapted to a fat-added diet are reported to have higher muscle glycogen – they may utilize more fat during the warm-up period, leaving more muscle glycogen for the intense work. This is partially dependent on the makeup of the rest
... 40% of a horse’s daily diet may be offered as concentrated calorie feed.
of the diet and other variables. Horses fed diets that are severely restricted in starch and sugar while containing high levels of fat and fiber were shown to experience glycogen depletion when worked hard for five days.
Analysis of a horse’s diet should not focus on only one nutrient or ingredient. A horse may benefit from 4–8% fat in the diet to supply essential fatty acids and some glycogen sparing during maintenance and warm-up activity, but performance demands don’t necessarily benefit when higher levels of fat are fed. Beneficial effects are seen when a horse is fed a diet of 5–10% fat, but an amount above 10–12% may not only offer no improvement in performance but may also reduce muscle glycogen stores. There have been reports of slower speeds in sprint horses on fat-supplemented diets – feedback from some race trainers (especially Quarter Horses) indicates that some horses on a higher fat diet are too ‘laid back’ and not ‘on the muscle’ or as ready to run. This may have as much to do with whether or not there is ade- quate starch and sugar in the diet to optimize glycogen stores as well as other components of the diet and how much fat is fed.
“How much a horse improves in performance related to fat supplementation depends on many factors – type, intensity and duration of exercise, type of fuel being burned in working muscle, other components of the diet and the total amount of intake and fat levels.”
102 SPEEDHORSE April 2021