Feb 17

Vitamin D deficiency – Fact and fiction in sheep

Back in 2007 there were diagnosed rickets in a range of hill hoggs (swales, cheviots and herdwicks) investigated by the VLA in 7 flocks in Northern England. Most were returning from wintering on dairy farms.

They showed signs of:

  • ‘Tip-toeing’
  • Stiffness
  • Prolonged recumbency
  • Two bowed legs

They were confirmed by bloods and post-mortem, most suspected D3 deficiencies had been anacedotal up until then. In those less severely affected a vitamin D drench was used and improvement was seen. Vitamin Drenches in sheep are adequate for approximately 6 weeks in the face of a dietary deficiency of D3.

At latitudes greater than 550 N, levels of UV radiation are adequate for synthesis of vit D3 between mid-March and mid-September only. It is likely that many sheep are subclinically deficient at northerly latitudes in winter and this may present as ‘poor doing’ hoggs. This is all variable depending on the weather conditions. They need early treatment i.e when ‘poor doing’ and ‘tip-toeing’ rather than before bones start deforming as once this happens there is no effective treatment.

If you are worried about wintering hoggs please ring us to discuss. There is an injectable vit D3 available but we have to import this so need a couple of weeks notice.Swaledale Sheep

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