Negative energy balance (NEB) occurs in early lactation, when feed intakes are insufficient to meet the energy demands of milk production.

It can materialise up to two weeks prior to calving and can result in the development of ketosis.

NEB

Almost all cows will be affected by some degree of NEB in early lactation, but when it becomes excessive or prolonged, issues can develop.

It can result in cows having issues such as ketosis, as mentioned, as well as fatty liver and displaced abomasum.

Indicators of an NEB issue in the herd are:

  • Less than 15% of early lactation cows with milk protein <3.05%;
  • Less than 15% of cows with a milk fat: protein ratio >1.4;
  • Less than 25% of cows with >0.

In severe cases, cows may have a lethargic look. It is likely that these cows will be off their feed and will have lost excessive body condition in a short period of time. This is because they would have mobilised body fat to make up for the NEB.

In a situation where a cow has lost a full condition score within the first 30 days of milk production, something needs to be done.

A situation like that is unacceptable and warrants a consultation with a vet.

Management

Dairy cows have varying nutritional requirements throughout lactation, but, undoubtedly, these requirements are at the highest during the first few weeks after calving. 

Because of this, it is important to determine the quality of the feed you are offering these cows.

Farmers should assess their cows’ body condition scores (BCS) on an on-going basis during early lactation and any cows with excess loss should be identified.

BCS needs to be monitored closely and milking diets should be introduced slowly to cows.

Cows should be fed a high-energy diet ahead of calving to help partially compensate for lower dry matter intakes post-calving.