On the majority of spring-calving farms the cows are now dry, and it is time to start looking at dry cow minerals.
Having cows in the correct mineral status in the dry period will help to prevent milk fever and associated problems such as a slow calving, retained placenta, ketosis and displaced abomasum.
But it is also important that dairy cows are in the correct body condition score (BCS) ahead of calving.
Dry cow minerals
You should discuss which dry cow minerals are required for your herd with your vet, advisor and nutrionist.
It is important that the mineral profile of both the forage and the mineral supplement are considered.
You should source a high-quality mineral and feed it at the correct rate for at least six-weeks pre-calving.
Many problems on farms occur when minerals are fed at the wrong rate or for too short of a period, so make sure to get these simple things right.
In terms of mineral specification, the main points are:
- Low calcium (<1.1%);
- 20-25% magnesium;
- 2-5% phosphorus (P) (feed at higher rate if forage P content is low);
- Vitamin D – at least 12,000 units/100g;
- Trace minerals – copper, zinc, selenium, manganese, iodine and cobalt with protected sources included where required.
Minerals are usually fed at a rate of 120g/cow/day; if you are dusting minerals on silage it is better to do it twice-a-day at a rate of 60g.
BCS
Along with feeding minerals to cows it is important to continue to monitor the BCS of your cows ahead of calving.
Issue around calving can also be caused due to cows not being in the correct BCS.
A spring-calving cow should be in a BCS of 3.0 at calving; above or below this figure will lead to an increased risk of developing one of the issues outlined above.
At this point it will be difficult to get cows into the correct condition, so these cows need to be closely monitored.
These cows should be considered a high risk for potential issues before, during and after calving.