Good Practice based on Current Knowledge

Lactation tetany

• Use plants in the sward (e.g. legumes) containing a higher level of minerals, including magnesium.
• Avoid high potassium levels in the sward.
• Consider moving calving dates away from risk periods.
• Provide adequate shelter for the animals.
• Avoid long periods of fasting.
• Cows in early lactation should be supplemented (epsom salts, dolomitic limestone, magnesite, magnesium phosphate, mineral licks, etc.).
• Frequent dusting of pasture during periods of risk with dolomitic limestone or calcined magnesite may be helpful.
• On farms where lactation tetany is a problem, dressing the pasture with kieserite may be a long-term solution.
• Treat affected cows with products containing both calcium borogluconate and magnesium hypophosphite, both intravenously and subcutaneously, administered by the veterinary surgeon.
• Homoeopathy may be used to aid recovery.
• Feed calves by hand until the cow has completely recovered.
• To prevent further cases of lactation tetany the herd should be moved off the danger area and onto some permanent pasture or longer-term ley.
• Supplement the affected group with magnesium oxide (magnesite) (120 g/day), magnesium phosphate (54 g/day) and epsom salts (MgSO₄).

Hypomagnesaemic tetany of calves

• Offer hay to stimulate rumination and salivation.
• Supplement calves at risk with magnesium oxide or magnesium carbonate.