How to Increase the Twinning Rate in Sheep: 6 Factors You Control

To increase the twinning rate in sheep, work on six things together: keep ewes and rams from dams that twin, flush ewes before mating, keep them in moderate body condition, rely on ewes in their prime breeding years, reduce heat and stress at mating, and record every lambing so you can cull ewes that keep producing singles.

Twins mean more kilos of lamb from a ewe that eats about the same feed all year, which makes them one of the strongest profit levers in a flock. They also mean more work: smaller lambs, a bigger need for colostrum and closer supervision. So the goal is not the highest possible number, but the number the ewe and your management can raise to weaning.

Genetics: the ceiling feed cannot break

Breed comes first. Some breeds are known for high twinning, while others mostly produce singles. Many hardy local breeds in hot, dry regions were selected for heat tolerance and survival on poor grazing rather than for litter size.

Within a breed there are still clear differences between families. A daughter of a ewe that twins regularly is more likely to twin than the daughter of a single-bearing ewe. That makes replacement decisions (which females you keep for breeding) the place where you build twinning over the long term:

• Keep twin-born ewe lambs from dams with a repeated twinning record.
• Choose a ram whose dam was a reliable twinner; he passes that trait to his daughters.
• Do not judge a ewe on her first lambing alone; maiden ewes produce singles more often.

For detailed ram selection criteria, see how to choose a breeding ram.

Nutrition and body condition before mating

A ewe that is gaining weight going into mating releases more eggs. That is the principle behind flushing: raising energy for a few weeks before the ram goes in and into early mating. The practical details are in the guide to flushing ewes before mating.

Key points:

• Moderate body condition (about 2.5 to 3.5 on a 5-point scale) is best. Thin ewes release fewer eggs; very fat ewes do not benefit and can become less fertile.
• Minerals and vitamins matter for fertility; shortages of certain trace elements in some areas reduce ovulation. Ask a nutritionist or your vet what your region needs.
• Keep feeding steady after mating: twins are sometimes lost after conception when nutrition drops suddenly in early pregnancy.

Age, health and the ram

Ewe age. Twinning usually rises after the first lambing, peaks in the middle productive years and declines with old age and worn teeth. A flock with many maiden or aged ewes will show a lower twinning rate.

Health. Anything that causes weight loss or fever around mating hurts ovulation and embryo survival: worms, lameness, chronic mastitis and infectious diseases that cause abortion. Vaccination programmes must follow your local vet or ministry schedule.

The ram. A tired, feverish or lame ram serves fewer ewes, so cycles are missed and lambing spreads out. Check him several weeks before the season and keep a sensible ram-to-ewe ratio for his age and condition.

Heat. Heat stress at mating reduces fertility in both rams and ewes. In hot regions, mate in the cooler months where possible and always provide shade and cool water.

Table: what you control and how long it takes

Records: without them you cannot tell which ewe deserves to stay

Memory is not enough in a flock of a hundred head. To build a real twinning rate you need to know, for every ewe: how many times she lambed, how many lambs each time, how many survived to weaning, and who her dam and sire were.

In Throf all of this sits on the animal's card: number and tag colour as identity, dam and sire, mating date, pregnancy, and birth as single, twins or triplets. Over time it becomes easy to pull a list of ewes that have twinned more than once to keep for breeding, and ewes that have had three singles in a row as candidates for sale. That simple comparison, season after season, is what actually raises the rate.

Remember that twins need preparation before lambing: enough colostrum, a ready lambing pen, and watching for ewes that reject the second lamb. See the lambing season checklist.

Mistakes that lower twinning without you noticing

• Selling the best females: selling twin-born ewe lambs because they are smaller and keeping the big singles lowers the rate generation after generation.
• A ram of unknown origin: you know nothing about his dam's fertility.
• Mating at the peak of the heat with no shade or cool water.
• Cutting feed abruptly after the ram is removed.
• Judging by impression: "I feel there are more twins this year" is not a number.