With tough seasonal conditions, Livestock SA is warning to be vigilant as supplementary feeding increases the risk of hypocalcaemia (milk fever) in ewes.
Milk fever causes very low levels of blood calcium, most common in late pregnancy or the first few weeks after lambing, and can quickly lead to paralysis and death.
Milk fever is often seen in conjunction with low blood magnesium (hypomagnesaemia or grass tetany), and confusion between it and pregnancy toxaemia is common.
Early signs include staggery gait, muscle tremors, sheep move or struggle when approached. Affected sheep go down in a sitting position with their head turned around to their flank or may appear very weak and unable to stand.
Death will occur within 24 to 36 hours of initial signs.
Preventative measures can be taken to lessen the risk.
Ewes in the last month of pregnancy or with young lambs should be handled as little as possible to avoid physical stress.
Avoiding grazing of late pregnant or lactating ewes on excessively lush pasture or cereal crops can also reduce the risk of developing the condition.
Producers should supply a mix of two parts stock salt to one part stock lime throughout pregnancy and lactation.
If ewes have been in confinement consuming more than 50 per cent grain-based diet, stock lime or calcium supplements should be continuously available.
To treat milk fever, which is often seen in conjunction with low magnesium, a solution containing both calcium and magnesium is recommended – this is readily available from most rural stores.
Treatment must be given as soon as possible after initial signs to be effective.
Consult your veterinarian for tailored advice.
