Rickets in lambs (August-September 2014)
The early autumn break and good follow up rains in the southern area of the Central West LLS saw early sowing and grazing of cereals crops across the region. The weather then turned very gloomy over July with very few sunny days. This in combination with short day light hours has resulted in a number of cases of rickets in autumn drop lambs across the area.
Rickets is a condition in young animals where the bone fails to harden properly. Lambs may appear stiff and lame. Bones are easily fractured. Some lambs will become recumbent and reluctant to rise. Symptoms are exacerbated when lambs are handled.
Rickets is caused by vitamin D deficiency. Vitamin D along with adequate levels of calcium and phosphorus are required for normal bone development in a growing animal.
We see rickets in autumn drop lambs grazing cereal crops in particular oats. It is thought that high levels of carotene (vitamin A) antagonise the action of Vitamin D in the body.
Therefore rapidly growing lambs on cereal crops during winter are at risk of developing rickets.
If a flock is diagnosed with rickets generally it is too late to intervene as daylight hours are increasing as are sun light hours. This increases Vitamin D in the body. Handling of lambs may also exacerbate the problem.
Our recommendations to sheep producer grazing cereal crops, has always been to provide a loose lick of lime, salt and causmag to increase calcium, magnesium and sodium intake. However this may not be enough to prevent rickets in which case an injection of Vitamin D given to the lamb at marking and/or weaning is also recommended.
If you have any questions please contact your local District Vet...