Ewe Nutrition: Meeting Metabolic Needs Across the Production Cycle

Ewe Nutrition Throughout the Production Cycle

Nutritional management of the ewe is the single most important welfare intervention available to sheep producers. Inadequate nutrition causes metabolic disease, poor reproductive performance, lamb mortality, reduced milk production, and impaired immune function. Overfeeding causes obesity — associated with dystocia, pregnancy toxaemia, and poor lamb survival. Getting nutrition right across the production cycle requires understanding the dramatically varying metabolic demands at each stage and providing targeted nutrition accordingly.

Body Condition Scoring: The Foundation of Nutritional Management

Body condition score (BCS) is a rapid, cost-free welfare and management tool. Scored 1–5 (1=emaciated; 5=obese) by palpation of the spine and loin:

Target BCS at tupping (mating): 3.0–3.5 — correct BCS significantly improves ovulation rate (flushing effect)
Target BCS at scanning (mid-pregnancy): 2.5–3.0 — avoid loss during pregnancy
Target BCS at lambing: 3.0 — optimal for milk production and lamb survival
Target BCS at weaning: 2.0–2.5 acceptable; ewes should have used body reserves to support peak milk production

BCS should be assessed at each of these key production points. Ewes below target require additional nutrition; ewes above target require controlled feed restriction.

Nutritional Requirements by Production Stage

Dry Period (Post-Weaning to Tupping)

Lowest metabolic demand of the year
Focus on restoring BCS lost during lactation
Thin ewes (BCS <2.0) require priority feeding to reach target by tupping
Grass-based systems: move to fresh, better-quality pasture 3–4 weeks pre-tupping (flushing)

Tupping (Mating)

Good nutrition improves ovulation rate — flushing (improving nutrition 3–4 weeks before rams in) increases twin/triplet rates
Avoid sudden nutritional changes during mating — can disrupt embryo implantation
Ram nutrition equally important — thin rams have reduced libido and sperm quality

Early Pregnancy (First 10 Weeks)

Low foetal growth rate — maintenance nutrition generally sufficient
Critical period for embryo implantation — avoid stress, sudden dietary changes
Continue BCS monitoring; correct deficiencies gradually

Mid-Pregnancy (Weeks 10–15)

Moderate increase in requirements begins
Ultrasound scanning at day 60–80 — identifies litter size for targeted feeding
Group ewes by litter size for separate nutritional management

Late Pregnancy (Last 6 Weeks) — Critical Period

70% of foetal growth occurs in the final 6 weeks — nutritional requirements escalate sharply:

Singles: 1.3–1.5× maintenance energy requirement
Twins: 1.5–1.8× maintenance
Triplets: 2.0× maintenance (limit dietary bulk; increase concentrate)
Rumen volume is compressed by growing foetuses — increase feed frequency, not volume per feeding
Supplementation: selenium, vitamin E (deficiency causes white muscle disease in lambs), iodine

Lactation (Peak Weeks 3–6)

Highest nutritional demand of the year — ewes suckling twins require 3–3.5× maintenance
Even good nutrition allows some body reserve mobilisation — normal if BCS does not fall below 2.0
Ad libitum fresh, clean water essential — lactating ewe can drink 6–10 litres/day

Key Mineral and Vitamin Requirements

Selenium: Deficiency causes white muscle disease in lambs; supplement ewes 4–6 weeks pre-lambing
Copper: Deficiency causes swayback; check soil antagonists (Mo, S, Fe) before supplementing
Calcium/phosphorus: Correct ratio important; hypocalcaemia around lambing causes milk fever
Vitamin E: Works synergistically with selenium; immunostimulant pre-lambing
Iodine: Deficiency causes goitre and stillbirth in lambs; supplement in at-risk areas