Spring calving is just around the corner. Pre-calving minerals should be fed to cows for at least eight weeks out from calving.

Insufficient mineral supplementation can lead to calving difficulties, lethargic calves that are slow to get up and sucking by themselves, retained cleanings and knock-on effects on fertility during the breeding season.

In most cases, the diet being offered to the dry cow will not have sufficient levels of the required minerals to meet demand. Therefore, supplementation is necessary.

Most dry cow minerals will cover the basics, but you need to make sure all areas are covered.

Some farms will have more deficiencies than others and a blood test or liver biopsy is the best way to determine these.

The main minerals and vitamins to look for are listed in Table 1.

Powdered minerals can be offered as part of a total mixed ration (TMR) or top-dressed along the feed passage once a day.

Where top dressing is the method of choice, it is critically important that there is sufficient head space for all animals to feed at the same time.

Other methods

Other methods of supplementation include lick bucket or bolus. One benefit of using a bolus is that you are certain that all animals will receive the same level of mineral supplementation.

However, administering boluses to cows can be a laborious task. In order to ensure cows do not regurgitate the bolus when ruminating, boluses should only be given to cattle that have fasted for 12 hours.

Otherwise, the heavy mat of silage in the stomach can prevent the bolus from sinking to the bottom where it is supposed to stay.

One other thing to be aware of is that minerals have a use-by date - check the bag if using last year’s stock.