Body Condition at Lambing: Why Ewe Condition Determines Lamb Survival

Ewe body condition at lambing is one of the strongest predictors of neonatal lamb welfare, affecting colostrum quality, milk production, and maternal behavior.

Key Facts

Target body condition score at lambing is 3.0-3.5 on the 5-point scale for most breeds
Ewes below BCS 2.0 at lambing have significantly reduced colostrum volume and immunoglobulin content
Very thin ewes show impaired maternal behavior, reducing licking, suckling support, and bonding
Overfat ewes (BCS above 4) have increased lambing difficulty and prolapses, but produce adequate milk
Colostrum quality peaks in the first 6 hours post-lambing and declines rapidly
A ewe in BCS 3.0 produces approximately 1.5-2L of high-quality colostrum in the first 24 hours
Body condition is most effectively managed in the mid-pregnancy period before the last 6 weeks

Welfare Considerations

Ewe body condition at lambing has direct welfare consequences for both the ewe and her lambs. Thin ewes provide less colostrum of poorer quality, impairing passive immunity transfer that protects lambs from infection. Impaired maternal behavior in thin ewes increases mismothering and starvation risk. These effects cascade into higher lamb mortality and suffering. Managing ewe nutrition through pregnancy to achieve target body condition scores is one of the most effective welfare investments available - it prevents multiple causes of neonatal lamb mortality and suffering simultaneously.

What You Can Do

Score all ewes at scanning and adjust management groups based on condition
Manage thin ewes (BCS below 2.5) in separate groups with higher energy supplementation
Avoid late pregnancy overfeeding of fat ewes - priority is mid-pregnancy condition management
Check colostrum production and quality in thin ewes immediately after lambing
Supplement colostrum to lambs from thin ewes using stored or commercial colostrum
Monitor maternal behavior in lambs from thin ewes closely in the first 4 hours after lambing
Track lamb mortality by ewe body condition group to quantify welfare impact