Elizabeth Bell (FCG Midwest)

I recently visited a client whose youngstock were losing weight and suffering from eye issues, after many tests from the vet they found that they were deficient in vitamin A.

Cause:

Vitamin A deficiency is caused by the recent drought over the summer, not lack of nutrients in the soil.  During the drought green leaved plants (grass) produce less beta carotene (which is converted into vitamin A in the body).

Cattle and sheep store excess vitamin A for approximately 3 months in their livers, but if they are getting less than required especially when calving/lambing the calf/lamb will be deficient as well, as calves/lambs receive majority of their requirements through colostrum.

Beta carotene is synthesised by the plant and has no strong links to other nutrients, the synthesis is influenced strongly by environmental factors such as light, temperature and water availability.  There have been links found between nitrogen availability and beta carotene.  When nitrogen is low plant growth is reduced so the amount beta carotene produced is also reduced.

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Treatment: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

If your cattle or sheep are deficient, it would be worth testing the silage to see if it is deficient and then targeting later pregnancy cows with supplements and ewes before lambing to ensure offspring are receiving the nutrients they need from the colostrum produced.

If this is something your cattle or sheep could be suffering from, please contact your local vet for advice and tests.