🐏 Sheep Nutrition & Welfare Science 2025

How nutritional management prevents suffering in sheep flocks

Overview

Nutritional disease causes significant preventable suffering in sheep globally. Pregnancy toxemia (twin lamb disease), hypomagnesemia (grass staggers), hypocalcemia, and trace element deficiencies affect millions of sheep annually. These conditions cause pain, neurological signs, and death — but are largely preventable with appropriate nutritional management and monitoring. Understanding the welfare implications of nutritional disease motivates evidence-based flock nutrition programs.

Pregnancy Toxemia

⚠️ Pregnancy toxemia: affects ewes in late pregnancy carrying multiple lambs; causes neurological disease, recumbency, and death without treatment
⚠️ UK incidence: estimated 1-5% of late-pregnant ewes in many flocks; higher in thin ewes with twins/triplets

Pregnancy toxemia occurs when energy demands of late pregnancy exceed dietary energy intake, mobilizing fat reserves faster than the liver can metabolize ketone bodies. Affected ewes show depression, teeth grinding (pain indicator), blindness, and recumbency. Early cases respond to glucose supplementation and propylene glycol; advanced cases rarely recover. Prevention through body condition scoring and adequate late-pregnancy nutrition is far preferable to treatment.

✓ BCS monitoring at tupping and 6 weeks pre-lambing: identifies at-risk ewes for additional feeding; prevents 70-80% of cases

Hypomagnesemia (Grass Staggers)

Hypomagnesemia occurs when rapidly growing spring grass (high potassium, low magnesium) causes magnesium deficiency. Affected sheep show acute neurological signs including staggering, convulsions, and death within hours. It is almost entirely preventable through magnesium supplementation during risk periods. Daily magnesium in water, feed, or buckets prevents outbreaks. The welfare cost of hypomagnesemia — sudden, severe neurological distress and death in otherwise healthy animals — makes prevention investment highly worthwhile.