Pregnancy Diagnosis in Sheep: Ultrasound, Welfare, and Flock Management

Accurate pregnancy diagnosis in ewes using transabdominal ultrasound allows farmers to separate pregnant and non-pregnant animals and tailor nutrition accordingly — improving both welfare and productivity.

Key Facts

Transabdominal ultrasound can reliably detect pregnancy in ewes from 40–50 days after mating
It can also determine litter size (singleton, twin, triplet) which is critical for targeted nutrition programmes
Ewes carrying triplets or more require significantly higher energy and protein intake in late pregnancy
Undiagnosed pregnancy or incorrect litter count is a leading cause of twin lamb disease (pregnancy toxaemia)
Pregnancy toxaemia in ewes causes severe metabolic crisis, recumbency, and often death without intervention
Scanning ewes typically costs £0.50–£1.00 per head and is considered cost-effective across most UK flock types
New portable handheld ultrasound devices are making on-farm pregnancy scanning accessible to more producers

Welfare Considerations

Pregnancy diagnosis in sheep has direct welfare benefits. Ewes carrying multiple foetuses that are not identified and fed accordingly are at high risk of pregnancy toxaemia in late gestation — a painful metabolic disorder causing weakness, blindness, recumbency, and death. Scanning allows farmers to sort ewes by litter number and provide appropriately increased energy supplementation to those carrying twins or triplets. This single intervention prevents a condition that causes significant suffering in ewes and high lamb mortality. It also allows earlier identification of barren ewes, improving flock efficiency. Routine pregnancy scanning is now considered best practice in sheep farming.

What You Can Do

If farming sheep, invest in pregnancy scanning at 40–90 days post-mating as standard flock practice
Use litter size data to create separately managed feeding groups for singles, twins, and triplets
Ensure ewes carrying multiples receive adequate energy and protein from at least 6 weeks before lambing
Know the signs of pregnancy toxaemia and have a treatment protocol agreed with your vet before lambing season
Consider training in on-farm ultrasound use to reduce scanning costs and increase frequency