Common Worlds

Sheep Facts
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Matthew C. Claeys
Extension Livestock Specialist

Sharon B. Rogers
Extension Livestock Technician
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Sheep is a term for selective grazing animals that may be domesticated (tamed) or wild. This material will primarily focus on domesticated sheep. Behaviorally, sheep are gregarious, precocial, defenseless creatures. But what does that mean? Gregarious means that they flock together or like to be with a group. It is rare to see a sheep by itself because of their gregarious nature. Precocial means that they have a high degree of independence at birth. This means that they can stand on their feet shortly after birth. Sheep are defenseless for the most part against predators like coyotes and wild dogs. Sheep are also very selective in their grazing habits. Sheep have a split in their upper lip, with this they are able to pick the preferred leaves off of the plant.

At one time all sheep were wild. Around 10,000 BC sheep were domesticated by the humans. Most of the wool breeds of sheep were developed from Moulfan sheep. Most of the hair breeds are similar to the Urial sheep of ancient times. Prior to domesticating sheep, the dog and reindeer were domesticated.

As the animals were raised under tamed conditions, they went through several changes. On the outside the sheep began to develop more wool and less hair. The color of the wool and hair changed from brown and shades of brown to whites and blacks. Their ears became more of a lop ear than an erect ear. The horns that the wild sheep possessed were weakened and disappeared from many breeds. On the inside the sheep changed as well. These internal changes happened at both ends. The tails had less vertebrates, or bones than the sheep do now. Today's sheep also have a smaller brain than the sheep 12,000 years ago.

Sheep were tamed for several uses that still apply today. The sheep were first used for meat, skins, milk and wool. Sheep are still used for these basic purposes plus many more. Sheep by-products are in many items that we use everyday.

Ram male of breeding age
Wether castrated male
Ram lamb immature male
Ewe lamb immature female
Lamb newborn
Flock group (3 or more)
Tupping act of breeding
Lambing act of parturition (giving birth)
Birth weight 5 - 8 lb.
Average number born 1.1 - 1.4 lambs/year
Weaning age 2 - 3 months
Pasture carrying capacity 5 - 6 ewes & lambs/acre

Fine wool Merino (100%)
Medium wool 1/4, 3/8, & ½ blood
Long wool coarse, strong, luster, 12"/yr (English breeds)
Carpet wool lowest quality
Hair straight, non elastic & glossy

Life span 6 -11 years

Mature weight 90 - 300 lb.
Breeding season early fall to late winter (some are poly-estrous year around, ex. Dorset)
Estrous cycle 14 - 19 days seasonally poly-estrous
Duration of estrus 24 - 36 hr. (standing heat)
Time of ovulation 24 - 30 hr. from beginning of estrus
Gestation period 145 -155 days
Breeding/year 1 - 2/yr.

Ewe lambs
Puberty 5 - 8 months (80 - 100 lb.)
Minimum breeding age 8 - 10 months

Rams
Puberty 6 - 8 months
Mature weight 150 - 450 lb.
Serviceability 1 ram: 30-35 ewes (60 day breeding season)
Ejaculate volume 0.8 - 1.2 ml
Sperm concentration 2000 - 3000 million/ml
Motile sperm 60 - 80%

MOUTH & TEETH
20 Temporary teeth
32 Permanent teeth at maturity
4 pairs of Incisor teeth on lower jaw
Upper incisors missing
Cartilaginous (hard) dental pad on upper jaw
Split upper lip with mobile lips
AGE OF SHEEP (teeth)
Lamb 4 pair of Incisors
1 year middle pair of Incisors
2 years 2nd pair of permanent Incisors
3 years 3rd pair of permanent Incisors
4 years 4th pair of permanent Incisors
5 years all permanent Incisors close together
6 years Incisors begin spreading apart
7-8 years some Incisors broken
10-12 years all Incisors missing

This is probably more than you want to know.