Yield index highlights care of cow

A prediction of what a healthy cow should yield at her first milk recording in a new lactation can show how well feeding and management during the transition phase is working.

Ken Norland, University of Wisconsin, USA, has developed such a calculation for individual cows called the Transition Cow Index (TCI).

Previous milk recording history means milk recording companies, such as NMR in the UK, could provide this figure relatively easily.

“Knowing this figure for the first recording day would give a quick check on whether cows were reaching their potential yield and as such are healthy or sick,” he said.


This allows you to monitor whether transition phase management is working or a change in it has been successful in a short time.

“Using TCI we can monitor cow health quickly after calving, without the subjectivity of farm records, as influenced by preventative and therapeutic programmes on farms.”

Where results are below TCI predictions, he advised using it in conjunction with first milk test fat to protein ratio.

A high fat percentage is associated with ketosis and fatty liver.

“When a cow is producing 6% fat and 3% protein milk the ratio is two and she is at high risk. It should be below about 1.4 and when it’s above this in more than 40% of cows we investigate it,” said Mr Norland.