May 12, 2009

Facial Eczema (FE). Farmer Information. Part 15. (Sheep & beef cattle). Grazing management.

Agriculture, farming, animal husbandry, animal health, disease, Facial Eczema, zinc, sheep and beef cattle, grazing management, advice, recommendations

By Dr Clive Dalton

Original 1991 information written by Dr Barry Smith and Dr Neale Towers, Ruakura Agricultural Research Station, Hamilton, New Zealand.

15. Facial Eczema: (Sheep and beef cattle). Grazing management.
  • Planned grazing can substantially reduce the risks of FE in hill country. Good planning is essential and it must start months in advance.
  •  Identify the safe areas on your farm and aim to have a feed bank on these areas for the FE season.
  • Learn about spore counting - contact your veterinarian.
  • The best way to identify the safer areas on your farm is by regular spore counting over several years - but in the meantime the shady south facing faces are generally safest.
  • Spore counts on easy rolling paddocks and those facing north are generally higher than those on southern faces.
  • Fence the safer areas separately so that grazing of these areas can be controlled.

Safer Pastures
  • Spore counts are generally lowest on hillsides of low fertility grasses like browntop, sweet vernal, Yorkshire fog and danthonia. Summer growing grasses like kikuyu or paspalum are also safer.
  •  Slopes exposed to prevailing drying winds also tend to have lower spore counts -but remember that a change in wind flows may result in normally safe paddocks becoming dangerous and visa versa.
  • Pastures that have been allowed to become rank during Nov-Jan and have a lot of standing dead leaf and grass stems also tend to have low spore counts. These pastures may not look good but have a value of their own in a FE season.
  • Ryegrass-white clover dominant pastures are the most dangerous especially if they have been burnt off in a dry summer followed by light rains during a humid autumn.
Safer Grazing
  • Avoid hard grazing.
  •  The spores are concentrated in the litter at the base of the pasture so the harder the sheep graze the greater the risk of FE.
  • Light grazing will require good early planning or you will quickly run out of paddocks. 

  • Aim to:
  •  (1). Maximise feed available on safer areas of the farm.
  • (2). Minimise stock numbers.
  • Spread animals widely if set stocked or use a fast rotation leaving a high residual pasture mass.
  • Do not try to retain young stock into late summer and autumn just to reach higher carcass weights.
  • Aim for an early, compact lambing so that you get an early weaning and the maximum number away at good weights before the FE season.
  • MAF trials showed that keeping lambs until March increased the grazing pressures on the breeding ewes and made the subsequent FE outbreak much worse. 
  • More ewes died and those that survived produced fewer lambs the following spring.  The losses far outweighed the added return from the six weeks' extra lamb growth.
  • Cull other stock early.
  • Consider using hay, silage or crops early rather than heavily graze pastures.  The spores in the autumn saved pasture will lose toxicity with time.
Summing Up
  • Identify and fence the safer areas of your farm.
  •  Build up a feed bank on these areas for the FE season.
  • Graze these areas during FE danger periods.
  • Use these areas of poorer quality feed for breeding cows, ewes etc to reduce the stocking pressure on other parts of the farm.
  • Avoid heavy grazing.
  • Quit non-capital stock early.

This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.

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