Dry pregnant dairy cows will need a minimum of six weeks of supplementary mineral feeding. I say supplementary because the majority of the minerals and vitamins required by dry cows will be provided by their feed.

The dry cow mineral should provide what is lacking in the dry cow feed so by right, a mineral analysis of the dry cow diet should be conducted and a special formulation of minerals manufactured to meet the cows’ needs.

Off the shelf options

However, most manufacturers have an ‘off the shelf options’ based on typical mineral requirements of dry cows being fed silage ad lib.

The specification of these mineral packs differ, as do their prices. Some minerals and vitamins are more expensive than others so their inclusion rate will determine the overall price of the mineral pack.

More is not always better and if cows are not lacking in something feeding more of it might do more harm than good.

That said, more is not always better and if cows are not lacking in something feeding more of it might do more harm than good.

The main macro nutrients that can vary depending on specification is magnesium and phosphorus. Minerals should have at least 20% magnesium and at least 4% phosphorus.

On the trace element side, selenium and vitamin E have a symbiotic relationship and the inclusion of each varies between different mineral packs.

Another key consideration when feeding dry cows is the potash level of the silage. High levels of potash will tie up magnesium and could lead to an increase in milk fevers post calving. Dry cows should be fed a low potash silage wherever possible.