Improved heat detection in NI dairy herds has the potential to deliver £80 more per cow per year, Professor John Fetrow from the University of Minnesota told farmers at a farm walk near Omagh on Tuesday.

Speaking at the event organised by Thompsons Feeds on the farm of Drew McConnell, Fetrow explained that a 21-day pregnancy rate is a product of submission rate and conception rate.

He said that the average NI dairy farm has a 21-day pregnancy rate of 13% which comes from a 40% submission rate and a conception rate of 33%. “In most dairy farms here, the limiting factor is submission rates from heat detection,” he said.

Fetrow said that by increasing submission rates from 40% to 60%, a 21-day pregnancy rate increases to 20%.

His calculations, based on NI average figures, showed that this can deliver up to an extra £80 profit per cow per year.

“The financial return is largely made up of improved milk production because cows spend more time in lactation. Also, they get pregnant and live to the next lactation, reducing replacement costs. And older cows make more milk,” he said.

Options

The lowest cost option outlined by Fetrow to improve submission rate was tail-painting cows. “Most dairies need to move to some sort of aggressive heat detection programme which commonly means tail chalking cows,” he said.

However, Fetrow added that on many dairy farms this could require altering facilities. “Use of infrastructure-like self-locking stations to easily refresh tail chalk can typically increase submission rates from 40% to 60% on farms and is not labour-intensive,” he said.

Fetrow also outlined the use of hormones to synchronise cycles across a herd.

“This has a cost of around £20 per cow, which is significantly more expensive than in the US. It delivers £13 profit per cow on average or a 65% return on investment,” he said.

Based on a milk price of 20p/l, Fetrow acknowledged that this option, and the third option of using activity monitors to identify heats, might not appeal to most farmers at present.