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Rumbul Magnesium Bullets Product Range


A sustained release bolus containing an alloy of magnesium, copper and aluminium. Licenced to aid the prevention of hypomagnesaemia in cows and ewes grazing rapidly growing Spring grass. Rumbul helps farmers manage the magnesium status of their herd or flock over high risk periods.

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When to use Rumbul Magnesium Bullets

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•Effective prevention of grass staggers in dairy cows, ewes and suckler calves
•Certain supply of magnesium during high risk period
•Use pre-calving to help boost magnesium intake


Rumbul has been tested in several trials and the results have been published in peer reviewed scientific journals. Trial work has shown the following:

•Effective prevention of clinical hypomagnesaemia (grass staggers) in cows, ewes and calves
•Many farmers now give cows Rumbul Magnesium Bullets towards the end of the dry period to help mobilise calcium at calving.


Cattle - 2 bullets per head

Ewes - 1 bullet per head

Calves - 2 bullets per head

It is vital that bullets are dosed at least 2-3 days before the onset of the period of risk (e.g. day of turn out). Rumbul bullets take a day or two before starting to release magnesium.

The active life of Rumbul cattle is 28 days
The active life of Rumbul sheep and calf is 21 days

Always use the recommended Agrimin bolus applicator.  For more guidance please download our sheep bolus administration leaflet below

Rumbul Cattle are packed in units of 10 (enough for 5 cows)
Rumbul Sheep/Calf are packed in units of 20 (enough for 20 ewes or 10 calves)



Rumbul Magnesium Bullets for Cattle and Sheep

Rumbul packs

Cattle Applicator A-Rumbul Cattle Bullets

Rumbul gun

Rumbul Magnesium Bullets for Cows

Rumbul Boluses 8

Sheep Applicator A-Rumbul Sheep Calf Bullets

Sheep Applicator
Rumbul Sheep and Calves and Boluses
Colombia dairy
Cow Crush 2