In winter, be on the lookout for:
Copper deficiency in sheep and cattle
- Rapid pasture growth after good winter rains reduces the concentration of copper in pasture.
- Seasonal variation in the availability of copper from pastures makes sheep and cattle most at risk of a deficiency during late winter and spring.
Signs of copper deficiency:
Cattle
- loss of pigment from coloured hair especially around the eyes
- falling disease – sudden heart failure causing sudden death
- lameness.
Sheep and goats
- swayback or uncoordinated legs (enzootic ataxia) of lambs and kids
- loss of pigmentation in black-woolled sheep and steely or harsh wool
- increased incidence in fractures of the long bones and rib bones in lambs.
Read more on copper deficiency.
Arthritis in lambs
Bacteria causing arthritis can enter the bloodstream of lambs:
- via the umbilical cord at or soon after lambing, especially in wet pasture
- at marking (ear marking, tailing, castration)
- at mulesing when the lamb’s mother licks the wound (mulesing increases the risk of arthritis by seven times)
- at shearing via cuts (shearing lambs increases the risk of arthritis by four times)
- especially when held in permanent yards after shearing or after mulesing.
Signs of arthritis:
- swelling of usually two or more limb joints, including the elbow, front knee (or carpus), stifle (the true knee, in the hind leg) and hock joints
- lameness, with reluctance to walk and increased time spent lying down. Usually more than one joint is affected, so sheep will often walk with a short-stepping, shuffling gait and hunched back
- weight loss because of pain, reduced appetite and reduced mobility.
Read more on arthritis in lambs.
Grass tetany (hypomagnesaemia):
Grass tetany occurs when magnesium levels in pasture are low:
- in annual winter grasses and cereals
- in grasses grown on leached acid sandy soils
- when potash and nitrogen fertilisers are used and pasture growth is vigorous.
It may also be caused by:
- low-energy intake, fasting or sudden changes in feed availability or quality (e.g. bad weather/winter storms)
- stress such as transport or yarding.
Signs of grass tetany
- Animals are often found dead. There may be marks on the ground beside the animal indicating they were leg paddling before death (lying on their side with stiff outstretched legs that thrash backwards and forwards).
- Early signs include some excitability with muscle twitching, an exaggerated awareness and a stiff gait.
- Animals may appear aggressive and may progress through galloping, bellowing and then staggering.
- In less severe cases the only signs may be a change in the animal’s character and difficulty in handling.
Read more on grass tetany.
Call a veterinarian if you see signs of disease
If you observe signs of disease in your livestock, contact your private veterinarian or local DAFWA field veterinary officer. Full veterinary disease investigations of livestock are subsidised to support market access for livestock and livestock products and to enable early detection of an exotic disease.
Read more on the subsidised disease program.
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To provide feedback, email Dr Bruce Twentyman on bruce.twentyman@agric.wa.gov.au