Ewe longevity — the ability of ewes to remain productive members of the flock for multiple breeding seasons — is both an economic and welfare priority. Ewes culled prematurely due to preventable health problems represent a welfare failure as well as a financial loss. Understanding the key determinants of ewe longevity enables targeted management improvements.
Short productive lifespans in sheep flocks are often associated with: untreated or chronic lameness, progressive dental disease, body condition failure, and chronic disease (Maedi Visna, CAE, Johne's disease). These conditions cause prolonged suffering before culling decisions are made. Proactive management to maintain ewe health extends productive life and reduces the welfare cost of premature culling.
Lameness is the single most common reason for premature ewe culling. Foot rot and scald are the most prevalent causes. Chronic or repeated lameness causes permanent joint damage that eventually makes treatment ineffective. Early treatment (within 3 days of lameness onset) dramatically improves cure rates. Five-point lameness plans (vaccination, early treatment, foot bathing, cull of non-responders, biosecurity) significantly reduce flock lameness prevalence.
Dentition deteriorates with age — broken mouth ewes (missing or worn incisor teeth) have significantly reduced ability to graze effectively. Annual dental assessment at tupping or scanning allows classification of ewes by dental status: full mouth, missing 1-2 incisors, broken mouth, gummy. Managing broken-mouth ewes on softer pasture or supplementary feeding extends their productive life; culling gummy ewes before they lose condition prevents welfare compromise from chronic undernutrition.
Maintaining ewes at target body condition score (BCS 3.0-3.5 at tupping; 2.5-3.0 at lambing) throughout the production cycle is the foundation of ewe longevity. Thin ewes at tupping have poorer conception rates; thin ewes at lambing have poorer milk production, higher metabolic disease risk, and poorer lamb survival. Regular BCS monitoring enables timely nutritional intervention.
Maedi Visna (MV) and Caseous Lymphadenitis (CLA) are progressive diseases that shorten productive life. MV-accredited flocks have significantly better ewe longevity. Annual vaccination programmes for clostridial diseases, orf, and pasturella reduce disease-related premature culling.