Farmer Focus: Aiming to average 4.6 lactations by 2022

Breeding is always a big focus throughout May and June and it’s very satisfying to be in a position to remove the bulls after 11 weeks in July.

This year, we are really seeing the benefit of a more mature herd. Milk solids yield Is almost 9% higher than other years.

We have tried to simplify the system by creating set criteria for replacement heifer selection while using beef AI for the rest.

See also: Advice on using the most effective dairy fertility KPIs

Initially, we would have bred all cows bar the bottom 10% to dairy AI. But, over the years, we have become more and more selective for the ideal combination of fertility, production and health traits that keep cows in the herd longer.  

Our target average lactation for cows in the herd is an average of 4.6 lactations and, having brought in a higher level of replacements two years ago, we are currently at 3.6 lactations but hope to reach our target by 2022. 

A once a day (OAD) system has a few different considerations when looking at replacement rates.

Firstly, heifers are always going to be the lowest producers in the herd but more so in OAD. Our aim is to keep replacement rates below 20% while maintaining the mature engine of the herd to drive production.

With less pressure on the herd due to reduced walking and milking frequency, OAD brings benefits for fertility. These have been replicated in research herds finding higher conception rates, lower empty rates and higher six-week calving rates.

The same is seen in our own herd and we constantly strive to hit 67-70% conception rate to first service with a target of less than 7% empty after 10-11 weeks breeding.

High fertility performance drives efficiency and economic outcomes for the farm with research showing every 1% increase in six-week calving rate is worth £7.49 a cow (€8.22 a cow).

Considering the Irish national average six-week calving rate is 65%, the efficiency and economic gains are worth more than £18,000 by pushing that to 90% for an average 100 cow herd.  

July milk production is holding well at 4.26% protein and 5.39% butterfat (1.69kg milk solids a cow).

June milk supplied to our milk processor took a welcome price increase, rising to the equivalent of 38p/litre.


Gillian and Neil O’Sullivan are dairy farmers from southern Ireland. Read more.