Economic Breeding Index (EBI) can be used as an effective herd management tool across all dairy production scenarios, according to University College Dublin’s (UCD’s) associate professor of agriculture, Alan Fahey.

Speaking at a recent webinar, held to profile the results achieved by the Lyons’ Systems herd over the past five years, Fahey pointed out that two cows with the same overall EBI value could deliver two entirely different levels of performance.

One could be particularly high in terms of milk output, the other could be very high, where fertility is concerned.

“Overall EBI values reflect the sum of several different performance-related traits. So it’s important for farmers to examine the differing component values within the overall EBI, when it comes to making the breeding decisions that best meet the specific needs of their herds.”

Choosing bulls

“Farmers should also use a selection of bulls across a group of cows. This ensures that if one does not perform as required, the others can compensate. In other words, all is not lost,” Fahey added.

A specific bull should be used to complement the EBI component values of each individual cow. For example, a high milk bull can be used on a cow that already has a high fertility score.

Fahey confirmed that the cows in the Lyons Systems’ herd had been maintained in the top 1% of the national average in terms of overall ‘EBI’ value and the specific index for ‘milk’ figure from the start of the project.

Fertility Index

The fertility index value had remained at a top 10% classification level up to 2019, but had risen to a top 5% evaluation figure by October of last year.

Fahey commented:

Our objective has been to maintain a herd of high EBI cows with a balanced ratio for production and fertility. Breeding replacements that are positive for milk have also been a priority for the development of the project. To date, we have managed  to secure all these objectives.

Fahey pointed out that the actual performance achieved from a cow is determined by a combination of her actual genetic potential and the on-farm management systems that are applied.

“The environment a cow finds herself in can either add to or detract from her genetic potential,” he continued.

Genomic testing

“All the heifers’ calves born on the systems’ unit are genomically tested. This is helping us to decide which of these animals best meet the criteria we have set for the replacements we want to bring through,” Fahey said.

This is an approach that I would advise all dairy farmers to take. Each test only costs €22 and represents a very small proportion of the overall outlay involved in rearing a replacement heifer.

“The genetics and management systems employed on farms must complement each other. Farmers must decide what their breeding goals are and then stick to these for a number of years.

“EBI can be used to identify the cows and bulls that are suited for each system,” Fahey concluded.