Drought Exposed Overstocking on Irish Dairy Farms

This summer's drought functioned as a stress test for Irish dairy farms, exposing farms carrying too many cows for their grass growth capacity and forcing them into expensive concentrates and imported fodder.

Since Ireland's dairy industry began its rapid expansion a decade ago, stocking rate problems have been a recurring theme. Overstocked farms lose profit as production per unit drops and input costs climb, with the damage sharpest in drought years when grass growth collapses.

Maintaining the optimal stocking rate is one of the most crucial practices for protecting margins, and the arithmetic is straightforward. Each cow needs access to approximately 19-20kg of dry matter (DM) per day. Farmers can cross-check the size of their dairy platform against average grass growth, taking peak growth and seasonal growth curves into account, to find the farm's true carrying capacity.

What does Teagasc recommend?

A general guide from Teagasc links optimal stocking rate to tonnes of grass grown per hectare and the level of supplement fed:

• At 10t DM/ha grown and no supplement, the optimal rate is 1.5 cows/ha; at 1t DM/cow of supplement, it rises to 2.0 cows/ha.
• At 12t DM/ha, the range runs from 2.0 cows/ha with no supplement to 2.4 cows/ha with 1t DM/cow.
• At 14t DM/ha, rates span 2.3 to 2.9 cows/ha depending on supplement.
• At 16t DM/ha, the range is 2.6 to 3.1 cows/ha.

Every farm must adjust for land quality, cow size and other factors, but the table anchors the decision. 'Finding the sweet spot' also means matching derogation restrictions, banding and fertiliser allowances.

Why does 3 cows/ha mark the danger line?

Farms stocked at 2.5-3 cows/ha generally manage growth and demand efficiently, keeping demand below the average grass growth curve from April to September. Above 3 cows/ha, and especially at 3.5 cows/ha, farms struggle with grass availability through the summer months, a risk that grows as droughts become more common.

At 4 cows/ha, demand surpasses even peak growth. That costs farms twice. Cow performance falls, silage production drops, and concentrate use runs well above the typical farm, adding financial pressure.

Overstocking also blocks pasture renewal. There is not enough grass in front of the herd to cover the two-month turnaround a reseed requires, so farmers skip reseeding. That choice looks acceptable in the short term but reduces profit per hectare as swards age and grass growth declines.

The problems extend into the autumn. Overstocked farms struggle to build covers in the backend of the year because demand outpaces growth early in the back shoulder, leaving many short of feed in the final months.

Is understocking the answer?

No. Surplus covers build, pastures become too heavy to graze, and while abundant silage is useful, repeatedly generating excessive surpluses is counterproductive.

The practical advice as margins tighten: evaluate the current stocking rate before the next grazing season. But avoid rash culling to hit a target number, because a sudden cut to the herd can disrupt other factors, including banding. Match the rate to measured growth, supplement level and the regulatory limits the farm operates under, and the drought becomes a diagnostic tool rather than a financial setback.