Body Condition Scoring of Sheep

Body Condition Scoring of Sheep

One of the most important management skills of livestock keepers is the ability to quickly and easily access the body condition of their animals, on a regular basis - irrespective of the number of animals kept. Body condition scoring enables the livestock keeper to more closely maintain progress towards desired goals of productivity and/or reproduction. Body condition scoring is largely an index of the amount of muscle and degree of fatness of the animal.

Body condition scoring methods have been developed for horses, cows, sheep, goats, and chickens. They are used for evaluating the adequacy of previous feed supply, determining future feed requirements, assessing the health status of individual animals, and establishing the condition of animals during routine animal management. Condition scores are also useful during assessment of animal welfare.

Body condition scoring needs to be approached in a systematic manner. Systems have been developed based on an index of either 1 to 9, or 1 to 5. In each case a score of 1 is used to describe animals that are extremely emaciated, and the maximum score of 5 or 9 describes animals that are very fat or obese (extreme examples may even have difficulty walking).

Why Condition Score

Many of the poor health conditions that sheep suffer from tend to reduce their ability to feed or impair their digestion. This can result in rapid weight loss, leading to further loss of condition and ultimately to death of the animal. However, simply looking at a sheep does not normally provide enough information for assessment of condition. Condition scoring is a simple method of assessing the condition of sheep by placing the hand over the backbone in the area just behind the rib cage. Scoring is done on a scale of 1 to 5, where 1 is emaciated (extremely thin), and 5 is very fat.

You can find the equivalent correct spot on yourself by resting you hands on your hips with the thumbs pointing forwards, and the fingers touching each other over the spine. In sheep the bones of the spine are more prominent than in man and feel sharp if the animal has little muscle and very little fat (e.g. score 2). An over fat sheep has such a thick fat layer that it is difficult to feel the bones of the spine (score 5).

Anatomy of the Loin

Body Condition Scores

Score

Description

Details

Extremely emaciated

All individual vertebrae can be felt easily. There is no muscle or fat covering the bones. Sheep in this condition have a serious problem and should normally be culled immediately

Backbone	Prominent and sharp
Short ribs	Ends are sharp and easy to press between, over and around
Eye-muscle	Thin, the surface tending to feel hollow

Lean

Individual bones can be felt, but they are rounded rather than sharp. There is some muscle covering the bones, but this feels concave rather than convex.

Backbone	Prominent but smooth
Short ribs	Smooth well-rounded ends can feel between, over and around each smoothly
Eye-muscle	Reasonable depth with the surface tending to feel flat

Just Right or
Good Condition

The ends of the transverse processes of the vertebrae can be felt only with firm pressure. There is good full muscle with some fat covering the bones, and this feels convex rather than concave.

Backbone	Can be felt but smooth and rounded
Short ribs	Ends are smooth and well covered firm pressure necessary to feel under and between short ribs
Eye-muscle	Full and rounded

Fat

The ends of the bones are not detectable, but their position can just be made out with very firm pressure. There is a thick covering of fat over the muscle covering the vertebrae.

Backbone	Detectable with pressure on the thumb
Short ribs	Individual short ribs can only be felt with firm pressure
Eye-muscle	Full with a covering layer of fat

Grossly Fat or Obese

Nothing can be detected under a thick layer of fat covering the loin; even the tips of the spinous processes of the backbone are buried in fat.

Backbone	Can be felt with firm pressure
Short ribs	Cannot be felt even with firm pressure
Eye-muscle	Muscle cannot be felt due to a thick layer of fat

Condition scoring the ewe flock can be a useful management tool. A producer can classify ewes into groups according to fullness of muscling and amount of fat cover. While it is subjective, it is accurate enough to indicate the nutritional status of individual ewes as well as an entire flock. Ewes can be scored several times during the year. Perhaps the most important time is five to six weeks prior to lambing.

Knowing condition scores, livestock owners can make adjustments in the feeding program either to save money or to prevent problems resulting from poor condition. There is an optimum condition (score) for each ewe in the flock for each stage of the production cycle. In general and for best performance, condition scores should be higher before and during gestation, whilst scores are likely to be lowest after lambing and before weaning.

Trials over a long period by DEFRA in the UK have shown that thin ewes (below condition score 2) and fat ewes (above condition score 4) will never perform to their full ability, because:

At Mating:

They do not come on heat when the rams are first turned in.

They have erratic heat periods, shedding fewer eggs.

They may stay barren or become so in early pregnancy due to foetal resorption.

In mid to late pregnancy:

They are more prone to twin-lamb disease (pregnancy toxaemia).
They are more likely to die when out-wintered.
They are more liable to vaginal prolapse, especially over-fat ewes fed ad lib roughage or arable by-products.

and at Lambing:

They may have difficult births.
They produce fewer and weaker lambs, resulting in higher lamb losses

They have a poor colostrum and milk supply.

Different breeds of sheep will also tend to have a range of different standard criteria for assessment of condition according to this five-point scale. In the Somali (blackhead Persian) and other fat-rumped sheep, an additional indicator of condition is the size and fat covering in the rump and tail.

Good condition

In contrast, another animal from the same group, and without a lamb, has a smooth spine with full muscles and moderate fat cover. The rump and tail show increased fat cover compared to the thin ewe illustrated on the right of the page.

Lean or thin

This fat-rumped ewe from western Kenya has lost condition, most likely as a response to lactation. The backbone is prominent. The angular appearance clearly shows reduced muscles with little or no fat cover. In particular the rump has more or less no remaining fat cover. (Compare with the animal on the left of the page).

Ewes in this condition should be
provided with supplementary feed.

References and Further Reading

Cissé, M., M'Baye, M., Sane, I., Corréa A. & N'Diaye, I. (1994). Seasonal changes in body condition of the Senegalese Sahel goat: relationship to reproductive performance. In: Proceedings of the Second Biennial Conference of the African Small Ruminant Research Network AICC, Arusha, Tanzania, 7-11 December 1992. International Livestock Centre for Africa (ILCA)/Technical Centre for Agricultural and Rural Co-operation (CTA) P.O. Box 5689, Addis Ababa, Ethiopia
DEFRA: Welfare of sheep. Department for Environment, Food and Rural Affairs
Suiter, J. (1994). Body condition scoring of sheep and goats. Department of Agriculture, Western Australia. Farmnote 69/1994
Thompson, J. & Meyer, H. (1994). Body Condition Scoring of Sheep. Oregon State University Extension Service.
Winter, A. & Charnley, J. (1999). The Sheep Keeper's Veterinary Handbook. The Cotswold Press.