This increase may seem small, but there will be a higher proportion of herds with more than 100 cows.
These figures were presented at recent Teagasc/Lakeland Dairies joint expansion open day held in Co. Meath recently.
He also said the the average working week reduces as dairy herds expand, but this is only a slight reduction.
Farmers with 0-80 cows work 64 hours each week, while larger farmers with herds of 161+ cows work for approximately 61 hours, according to Teagasc data.
However, he said this is not the case for all farmers.
“Some farmers have run into difficulty, they found that their own work load increased as herd size increased.
“This is something serious to consider, if farmers carry an additional 50-100 cows, who is going to do the work load. Is it going to be a sustainable work load?”
With this expected increase in cow numbers farmers will have to think long and hard about the additional labour they might require on farm, he said.
Clarke added that the labour requirement into the future will be based on the simplicity of the farms operation.
Clarke also highlighted the additional labour units farmers require as their herd size increases.
A herd milking 0-80 cows will require 0.5 additional labour units, this is mainly in the form of a paid or unpaid family member, he said.
If this herd increased to 80-120 cows the farm would need an additional full unit of labour (50% family 50% paid).
When herd size increases to 120-160 cows, the farmer will require an extra 1.4 labour units. So essentially if help from family is considered as 0.5 labour units, this farm will require a full additional labour unit.
While farms milking in excess of 161 cows will require an additional 2.4 labour units, he said.
The system will dictate to a large extent when additional labour is required. How complete or how simple the system is will dictate the level of labour required.
According to Clarke, as the farming system becomes more complex the need for labour will also increase. The more efficient farmers in recent years have moved to reduce the work load by adapting simpler farming systems.
Cow numbers also have an impact on efficiency, as the farmer is dealing with more cows at any one time, farmers tend to become more efficient as the herd increases, he said.