Grass growth: Things looking better than they may seem

The warm temperatures and bouts of rain have meant that grass is still growing well on farms across the country.

In terms of average grass growth rates, PastureBase Ireland figures are showing 57kg DM/ha in Ulster, 58kg DM/ha in Leinster, 55kg DM/ha in Connacht and 60kg DM/ha in Munster.

While growth rates are high, nationally, the majority of farms have not achieved their target average farm cover for this time of the year.

This is particularly evident on farms which are at a stocking rate of three cows/ha or greater.

Every effort should be made, while growth rates are high, to build covers – in order to extend the grazing season and to leave the grazing platform with a sufficient cover of grass, at housing, for grazing the following spring.

To build grass on the farm, demand must be reduced to below grass growth rates. However, on lowly stocked farms demand is usually already below growth rates this time of the year.

So, if grass growth is 60kg DM/ha/day, demand (stocking rate by intake) should be below this.

For instance, if demand was reduced to 50kg of DM/ha – at a stocking rate of 3.5 cow/ha and at this growth rate – 10kg of DM/ha/day or 70kg of DM/ha/week would be available as surplus.

Options to reduce the demand:
  • Increase supplementation through the introduction of concentrates and/or good-quality silage;
  • Removal of under-performing/empty/lame cows from the milking platform;
  • Bring zero-grazed grass from an outside block back home to feed.

Reaching residuals and keeping grass in the diet

Residuals must continue to be met during the final leg of the grazing season – to ensure that there won’t be a build-up of dead material before paddocks are closed.

A target residual of between 4cm and 4.5cm must be met. This will also stimulate grass growth and the development of a new generation of tillers.

Where residuals are not being met the strip wire may need to be re-introduced. This can often be the case when silage is being fed or when pre-grazing yields reach over 2,000kg of DM/ha.

Some areas in the west and northwest have received well above normal rainfall amounts, making grazing conditions difficult.

Grazing strategies in poor weather conditions:
  • Use on-off grazing;
  • Use off-spur roadways;
  • Use a back fence;
  • Graze in 12-hour blocks.

Farmers should aim to keep grass in the cow’s diet as much as possible through the use of these simple and effective grazing strategies.