Lambing Diseases and How They Can Be Mitigated
Most lambing problems are predictable and preventable. If lamb losses rise, look back at ewe nutrition first. Good feeding doesn’t just improve performance; it prevents disease before it starts.
From feed trough to lambing shed: preventing disease through nutrition
Many of the health problems seen at lambing are often blamed on weather, hygiene or bad luck. In reality, a large proportion of ewe and lamb disease can begin weeks earlier at the feed trough.
Late pregnancy is the most demanding stage of a ewe’s year, where lamb growth accelerates, rumen space is reduced, and the margin for error becomes very small. If feeding does not keep pace with rising energy, protein and mineral demand, problems can develop quickly.
Why late pregnancy is high risk
In the final six weeks before lambing, foetal growth increases sharply while the expanding uterus limits forage intake. Unless diets are matched to litter size, forage quality and ewe condition, shortfalls are almost inevitable.
The consequences include twin lamb disease, milk fever, grass staggers, poor colostrum production, weak lambs and higher lamb losses.
Feeding alone isn’t enough: monitoring matters
Feed tables are useful, but good flocks don’t just feed they monitor.
Key indicators include body condition score (BCS), feeding behaviour and lamb outcomes.
Ewes should be condition-scored at scanning, six weeks pre-lambing and again two to three weeks before lambing. Loss of more than 0.5 BCS in late pregnancy is a serious warning sign.
Ewes hanging back, being bullied or failing to come to feed are often the first signs of trouble. Weak lambs, watery mouth, joint ill and hypothermia frequently reflect nutritional problems that occurred weeks earlier.
Twin lamb disease starts before lambing
Pregnancy toxaemia (twin lamb disease) results from inadequate energy intake in late pregnancy. When glucose supply falls, ewes mobilise body fat, leading to ketosis and liver damage. Twin- and triplet-bearing ewes are at greatest risk.
Once a ewe is down, treatment success is limited, prevention is far more effective. Risk is reduced by feeding to scan results, increasing energy density without increasing bulk, splitting concentrates into multiple feeds and ensuring adequate trough space.
Milk Fever and Grass Staggers
Milk fever (low calcium) and grass staggers (low magnesium) are both linked to reduced feed intake and inconsistent mineral supply around lambing.
Milk fever often presents at lambing with weak or collapsed ewes that respond well to early treatment. Grass staggers can cause sudden deaths, particularly where magnesium intake fluctuates or forage potassium levels are high.
Consistent feed intake, reliable mineral supplementation and avoiding long fasting periods are key prevention measures. Magnesium supply, in particular, must be continuous, interruptions can cause problems within days.
Prolapse risk and body condition
Over-fat ewes and bulky, low-energy diets increase abdominal pressure in late pregnancy, raising the risk of vaginal prolapse and difficult lambing’s.
Avoiding over-conditioning earlier in the year, allowing enough feed space, grouping ewes by condition as well as litter size, balancing forage and concentrates all help reduce risk.
Colostrum: where lamb disease really starts
Colostrum intake in the first few hours of life is the single most important factor in lamb survival. Both quantity and quality depend heavily on ewe nutrition in the final month before lambing.
Poor nutrition leads to low antibody levels, increasing the risk of watery mouth, joint ill, septicaemia and early lamb deaths.
These diseases are often blamed on hygiene, but the underlying cause is frequently under-feeding weeks earlier.