EnduraBol® Pre-Calver

EnduraBol® Pre-Calver provides a sustained release of six essential trace elements and three key vitamins for up to 120 days. The boluses are suitable for pre-calving cows and heifers with a functional rumen >150kg live weight. Specifically formulated to support the pre- and post-period.

Available to purchase through agricultural merchants and vet practices. Each pack of 20 allows for treatment of 10 cattle in one quick and efficient application, using a specific bolusing gun, which is also available to buy and retail.

icon Active for up to 120 days
icon Suitable for pre-calving cows and heifers
icon Ideally administer 8 weeks pre-calving
Download Data Sheet Where To Buy

Ideal For

  • iconPre-Calving Stock
  • iconHeifers
  • iconBreeding Stock

A standard two bolus application provides the following quantities per day for up to 4 months:

Trace Elements Daily Supply (avg.)


4.00 mg


2.30 mg


96.60 mg


153.10 mg


17.60 mg


257.70 mg

Vitamins Daily Supply (avg.)


Vitamin E
19.60 iu


Vitamin A
8,062 iu


Vitamin D3
1,612 iu

How to Administer a Bolus

General Guidance

  • Administer to adult cattle weighing over 150kg live weight ONLY.
  • Two EnduraBol® Pre-Calver boluses should be given to each animal.
  • Before bolusing, the animal should be securely restrained.

Application Instructions

Load Applicator

  • Insert the flat end of the boluses into the chamber first.
  • Ensure both the boluses are securely held in the chamber of the applicator.

Inserting the applicator

  • Place the bolus end of the applicator into the centre of the cow’s mouth, to the back of the tongue.
  • Ensure the cow’s head and neck are extended in a straight line.


  • Severe pressure on the tongue.
  • Using force damaging teeth or any soft tissue.

Bolus Release

  • Gently squeeze the trigger, releasing the boluses over the back of the tongue.
  • Once the boluses have been ejected, further progress will depend on the swallowing reflex of the animal, the animal should easily be able to swallow the boluses.
  • Avoid using force which can cause damage to soft tissue.
  • Carefully remove the applicator, maintaining its central position in the mouth.

Contra-indications & Warnings

  • Only administer after seeking advice from your veterinarian or nutritional consultant regarding the trace elements status of your herd.
  • There is no need to administer additional copper, cobalt or selenium during the active life of EnduraBol® Pre-Calver (120 days).
  • DO NOT administer to animals weighing less that 150kg.
  • No meat and milk withdrawal period.
  • Do not drop onto hard surfaces.
  • Keep out of reach of children.
  • Do not administer to cattle with non-functional rumens, e.g. calves.
  • If applicable, simultaneous supplementation of additives with maximum content from other sources to those incorporated in a bolus should be avoided.

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