A case of milk fever can have a detrimental effect on a cow and her production during the subsequent lactation.
The majority of autumn-calving herds are now well into the calving season, with good management of cows and calves now key to success.
The transition cow period is the stage three weeks pre-calving and three weeks post-calving.
Dairy cows face many physiological challenges during this time, which is why getting this period right is key to having a successful lactation.
Autumn-calving
Problems with cows during the transition period usually arise due to poor management during this period.
Examples of issues that can arise during the transition period include: Udder oedema; milk fever; retained placenta; displaced abomasum (stomach); laminitis; metritis; ketosis; and fatty liver syndrome – all of which result in lost profits.
Good management of cows during the dry period is key, as mentioned, which includes ensuring that cows are fed adequate minerals and that body condition score (BCS) is monitored.
Cows that are a BCS that is too high should be classified as being high risk for developing issues during the transition period. Because of this, these cows need to monitored closely during this period.
Milk fever
Milk fever is often known as ‘the gateway disorder’, with the onset of lactation placing a huge demand for calcium (1.2–1.5g/kg of milk) on the cow.
If calcium supply (from the bones and diet) does not meet demand, the cow will become deficient in calcium (Ca).
Milk fever is most common in the first few days of lactation when the demand for Ca for milk production exceeds the body’s ability to mobilise calcium reserves.
A primary role of Ca in the cow is in muscle contractions – therefore a cow with either clinical or subclinical milk fever is at increased risk of developing a host of other problems which have been named above.
A case will also often happen when you are busy or in an area that is not ideal for treatment, including places such as the collecting yard or cubicle shed.
At a time of year when you are already busy, cases can increase stress levels on farms.
Because of this, any cows that may be at risk needs to be monitored closely and treated promptly if symptoms appear.