"Cold temperatures increase the amount of calories a horse needs to maintain body weight, as well as support activity or production. Because a horse may digest feed less efficiently as the temperature drops below the horse's comfort zone, additional feed may be required to maintain body weight and condition. It is important to maintain the horse in a body condition score of 5-6 (moderate to moderately fleshy) because a layer of fat under the skin provides insulation against the cold. Feeding an additional 1/4 lb of grain per 100 lb body weight to nonworking horses will provide adequate calories during cold, windy and wet weather. Working horses may require up to an additional 1/2 lb per 100 lb body weight, depending on workload, to maintain body weight during cold weather. Feeds such as Purina® Strategy®, Omolene #200® or Ultium® Horse Feed may be especially helpful in these situations, since the added fat provides more calories than grains alone.
The Ideal Body Condition Score is between 5 and 6-1/2
Animal extremely emaciated; spinous processes, ribs, tailhead, tuber coxae (hip joints), and ischia (lower pelvic bones) projecting prominently; bone structure of withers, shoulders, and neck easily noticeable; no fatty tissue can be felt.
2. Very Thin
Animal emaciated; slight fat covering over base of spinous processes, transverse processes of lumbar vertebrae feel rounded; spinous processes, ribs, tailhead, tuber coxae (hip joints) and ischia (lower pelvic bones) prominent; withers, shoulders, and neck structure faintly discernable.
Fat buildup about halfway on spinous processes; transverse processes cannot be felt; slight fat cover over ribs; spinous processes and ribs easily discernable; tailhead prominent, but individual vertebrae cannot be identified visually; tuber coxae (hip joints), appear rounded but easily discernable;
Tuber ischia (lower pelvic bones) not distinguishable; withers, shoulders and neck accentuated.
4. Moderately Thin
Slight ridge along back; faint outline of ribs discernible; tailhead prominence depends on conformation, fat can be felt around it; tuber coxae (hip joints) not discernable; withers, shoulders and neck not obviously thin.
Back is flat (no crease or ridge); ribs not visually distinguishable but easily felt; fat around tailhead beginning to feel spongy; withers appear rounded over spinous processes; shoulders and neck blend smoothly into body.
6. Moderately Fleshy
May have slight crease down back; fat over ribs spongy; fat around tailhead soft; fat beginning to be deposited along the side of withers, behind shoulders, and along sides of neck.
May have slight crease down back; individual ribs can be felt, but noticeable filling between ribs with fat; fat around tailhead soft; fat deposited along withers, behind shoulders,and along neck.
Crease down back; difficult to feel ribs, fat around tailhead very soft; fat area along withers filled with fat, area behind shoulder filled with fat, noticeable thickening of neck; fat deposited along inner thighs.
9. Extremely Fat
Obvious crease down back; patchy fat appearing over ribs, bulging fat around tailhead; along withers, behind shoulders and along neck, fat along inner thighs may rub together; flank filled with fat."