Assessing Nutritional Status

To assess the nutritional status of ewes, a subjective scoring system based on external body fat has been developed. The amount of fat cover is then used to estimate body energy reserves. The scoring system has a range of one to five, with one being extremely thin and five being extremely fat. The advantage of this system is that it is easy to use and is fairly reliable within a flock.

To score a ewe's body condition, use your fingertips to feel the fat cover over the vertebrae and ribs. However, the best area to estimate body condition is over the loin (vertebrae between the last rib and hip bone). In this area, palpate the spinous (vertical) and transverse (horizontal) processes of the spine to provide the most reliable estimate of body condition. The following illustrations (figs. 1-9*) show how to palpate this area and they describe the body condition scores.

Figure 1. Feel for fullness of muscle and fat cover. Figure 2. Feel for the spine in the center of the sheep's back behind the last rib and anterior hipbone. Figure 3. Feel for the tips of the transverse process.
Figure 4. Body Condition Zero. Sheep is extremely thin, unthrifty, and weak. Skeletal features very prominent (for example, backbone, shoulder blades, and ribs). Wasted muscle tissue is evident. Eye socket is prominent and sunken. May be humpbacked and isolates self from flock. Figure 5. Body Condition One. Sheep is extremely thin, unthrifty, but agile. Skeletal features are prominent with no fat cover. No apparent muscle tissue degeneration. Has strength to remain with flock. Figure 6. Body Condition Two. Sheep is thin but strong and thrifty, with no apparent muscle structure wasting. No evident fat cover over the backbone, rump, and ribs, but skeletal features do not protrude.
Figure 7. Body Condition Three. Sheep are thrifty with evidence of limited fat deposits in fore rib, over top of shoulder, backbone, and tail head. Hipbone remains visible. Figure 8. Body Condition Four. Moderate fat deposits give the sheep a smooth external appearance over the shoulder, back, rump, and fore rib. Hop bone is not visible. Firm fat deposit becomes evident in brisket and around tail head. Figure 9. Body Condition Five. Sheep are extremely fat with the excess detectable over the shoulder, backbone, rump, and fore rib. Excess fat deposits in brisket, flank, and tail head regions lack firmness. Sheep appear uncomfortable and reluctant to move about. Quality fleeces are generally found.