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Body Condition Scoring System

When examining a caribou and assessing its body condition, biologists use the rating system outlined in the chart below.  Ideally this assessment is done while the animal is alive such as when the satellite collars are being put on or before the carcass has cooled too much and the skin and tissues are no longer pliant. 

Shoulder	1	V-spined, very bony.  Hollow behind scapula, immediately behind spine
	2	Less bony.  Hollow still present
	3	U-shaped withers. Hollow filled
	4	Very broad, U-shaped.  Hard to feel edges of the bone
Ribs	1	Deep grooves between ribs, even immediately behind shoulder
	2	Ribs fairly well covered immediately behind shoulder (by the Latissimus dorsi).
	3	Can still feel ribs, but grooves are not deep
	4	Ribs nearly flush with tissue between them.
Hips/spine	1	Hip bones very distinct (no back fat). Spine very distinct.
	2	Some padding over hips. Spine very distinct.
	3	Hips fairly well padded. Spine partly covered along each side.
	4	Hips well padded.  Spine flush with or nearly covered with fat.

(Chart and system by Karen Gerhardt, PhD candidate, UAF – Chart supplied by Dorothy Cooley)

How else has body condition been measured?

The method of body condition assessment currently used by Yukon Government biologists uses a combination of the chart information above, and a mathematical processing of the shoulder weight, backfat depth, age of the animal, kidney fat, metatarsal marrow fat and length of the metatarsus. 

There have been numerous ways that body condition has been measured.  Below is a comparison of the various methods. 

Technique	Advantages	Disadvantages
Body Score Index Scores (the chart above)	It has been used in animal science for years; it has worked well on other wild ungulates.	It is difficult to standardise – one person can score quite differently to another; First Nation hunters are reluctant to palpate the animals; once the body cools it is not reliable.
Body Condition Index Scores (from short ribs)	Beef farmers have used it successfully, simple to do.	It must be felt and First Nation hunters are reluctant to do this.
Body Reserve Index	Good predictor of pregnancy	Requires body mass index score (see below)
Visual	Non-invasive	Confounded by season, hunters reluctant to use number system (ranked order)
Body Mass Index	Precise, repeatable, easy to understand	Hunters can’t weigh animals in the field, inconsistent (head on/head off, gutted, skinned, etc)
Carcass Mass	Hunters can provide carcass mass better than whole body mass	Inconsistencies ((head on/head off, gutted, skinned, etc)
Subcutaneous Back Fat Depth	Non-invasive for live animals, simple, good correlation with other measures of fat	Animals with no back fat still get pregnant, requires training to assess, inconsistencies, biopsy needle can cause infections, elders may disagree with using this technique
Ultrasound measure of back fat	Non-invasive for live animals, quick, easy, sensitive	Expensive, fragile equipment, highly technical, difficult to determine where maximum fatness is.
Kidney fat	Good correlation with total fat, standardised procedure exists, good index for low body conditions	Time of year affects correlation with total body fat, not sensitive in obese animals
Heart mass and Heart fat	Good correlation with heart mass and body mass, low heart mass and fat may be good indicators of extreme conditions.	Requires other characteristics (age, sex), Hunters do not like to give it up, some of the fat is hard to remove (coronary groove).
Marrow fat %	Good correlation with body fat in thin animals and with total body fat, a rating system for marrow texture and colour exists, not eaten or used.	Unknown how this relates to the condition of fatter animals, difficult to remove the marrow, requires other characteristics, removal best done in a lab rather than by hunters.
Mandible fat	Published regressions available, easily removed	Heads are often taken for eating, time consuming in the field.
Marbling Index Score		Caribou meat does not marble.
Leptin	Easy to collect blood and freeze, can sample live animals.	Insufficient research on this, lab analysis needed, sensitive to the time of day
Hydrogen Isotopes	Very accurate	Hunters/elders will not accept idea, ineffective in the field, requires subduing the animal for long periods of time.
Blood	Simple procedure for live or dead animals, pregnancy indicator (progesterone assay)	Cannot freeze or get too warm, requires lab equipment at sampling location.

From:  Kofinas, G., Russell, D.E., White, R.G.  2002.  Monitoring Caribou Body Condition Workshop Proceedings.  Technical Report Series No.396.  Canadian Wildlife Service, Ottawa, Ontario, 31 pp.