Pregnancy nutrition management in sheep is critical to ewe welfare, lamb vitality, and flock productivity. The final six weeks of gestation—when 70% of foetal growth occurs—place peak demands on ewe nutrition and welfare management.
Twin and triplet-bearing ewes face particular nutritional challenges as multiple foetuses compete for nutrients and physically compress the rumen, reducing feed intake capacity precisely when demand peaks. Energy and protein shortfalls in the final weeks before lambing compromise ewe welfare through pregnancy toxaemia, compromise immune function, and reduce colostrum quality and quantity. Body condition score management throughout the year sets the foundation for successful late pregnancy.
Pregnancy toxaemia is a metabolic disease of late pregnancy caused by inadequate energy intake relative to demand. Ewes mobilise body fat to compensate, producing ketones. Clinical signs include separation from the flock, dullness, stargazing, and recumbency—each representing progressive welfare deterioration toward death without treatment. Risk factors include multiple pregnancy, poor body condition, adverse weather, and sudden feed changes. Prevention through adequate late-pregnancy nutrition is far preferable to treatment.
Pregnancy scanning—using ultrasound to identify ewes carrying singles, twins, or triplets—enables targeted nutritional management. Separating the flock into nutritional groups based on litter size optimises resource allocation: triplet-bearing ewes receive highest nutritional support, single-bearing ewes require less. Scanning typically occurs at 70-90 days of pregnancy, providing 6-8 weeks to implement nutritional changes before lambing.
Trace element deficiencies have significant welfare consequences in pregnant ewes. Copper deficiency causes swayback (enzootic ataxia) in lambs—neurological disease with welfare implications detectable at birth. Selenium deficiency causes white muscle disease in lambs. Iodine deficiency contributes to stillbirths and weak lambs. Cobalt deficiency impairs ewe metabolism. Strategic supplementation based on forage analysis and blood sampling prevents deficiency-related welfare problems.
Housed ewes in the final weeks of pregnancy require adequate space for natural movement and lying, access to ad libitum fibre, and separation of lame or overconditioned individuals. Overcrowding increases disease pressure (particularly respiratory disease and Johne's disease transmission), reduces feed access for subordinate animals, and increases trauma risk. Pre-lambing pen inspections identify ewes requiring additional attention or separation.