As we progress further into March, the calving season continues, with the risk of milk fever within cows likely to increase.
This is due to a number of reasons, notably the length of times cows have spent dry, the condition of the cows, and their age.
It’s important that farmers continue to focus on safe management practices that will help to prevent cases.
Milk fever
Firstly, you need to ensure that you continue to give cows the correct amount of minerals; each cow should be receiving 100-120g/cow/day.
The quality of the minerals being offered to cows is also important. You should ensure that they have at least 22% magnesium included and high levels of Vitamin D (14,000 units plus).
Older cows in particular need high levels of Vitamin D to prevent milk fever.
Many farms have adopted the practice of operating a fresh cow group. Teagasc are advising that this should continue during the month of March, as it has a number of benefits for later calving cows.
Body condition
The body condition score (BCS) of the cows that are yet to calf need to be accessed.
To keep April and May cows under 3.5, you should restrict their intakes to between 10-11kg of dry matter (DM)/day for March.
This will help prevent them from becoming over conditioned, which in turn will reduce the number calving related issues.
These cows should continue to have access to ad-lib forage, with milk fever and other metabolic issues having to be managed at calving.
Head of Dairy Knowledge Transfer with Teagasc, Dr. Joe Patton recommended that farmers make sure that cows on the point of calving are fed low potassium (K) forage (under 2.2%).
He said that this is very important to prevent milk fever, and that if you don’t have low K silage in the yard, some bales should be purchased and fed for one to two weeks pre-calving.
Dr. Patton also noted that many farms use a ‘bottle under the skin’ at this point of calving to prevent milk fever.
However, Dr. Patton said that there is good evidence to suggest that this may increase risk of clinical/sub-clinical milk fever after 24-36 hours post-calving.
He recommended that farmers use a high calcium bolus with added Vitamin D instead of straight calcium bottles for this purpose.
Although Dr. Patton recommended that farmers do not use a calcium bottle as a preventative measure, it still has an important role to play on farms for the treatment of clinical cases.