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07 May 2025

Dealing with surplus grass this May

Dealing with surplus grass this May


With most farms now in a position of surplus grass, the Teagasc Grass10 team share key grassland management tips to maintain quality swards this May.

Growth rates are well above normal with the phenomenal weather we are currently experiencing and have increased to 77kg DM/ha and 67kg DM/ha, respectively on dairy and drystock farms.

Predicted growth rates from the MoSt model from Teagasc Moorepark indicate that growth rates will still be high at 60-80kg DM/ha/day over the next week. PastureBase Ireland (PBI) figures inform us that most farms throughout the country are in a surplus grass situation currently with >200kg DM/LU.

Excess grass supply must be tackled immediately. Grazing high covers >1500kg DM/ha will have a negative effect on animal performance, grass recovery and clean outs. If excess grass supply is not tackled, sward quality will be poor for the rest of the season. Learnings from previous years informs us that these paddocks in surplus grass must be removed immediately before stem arrives so as to speed up return to the grazing rotation.

How to deal with surplus grass during May

  • Walk the farm every 5 days
  • Pre Grazing Yield (PGY) above 1400kg DM/ha is a strong indicator of surplus grass
  • Post Grazing Heights (PGH) should be 4 – 4.5 cm (50-100 Kg DM/Ha)
  • Higher PGY results in higher PGH 5+ cm (200-250+ Kg DM/ha)
  • Cover/LU above 200kg DM/LU is also a strong indicator and current PBI data supports this with 60% of farms above this figure
  • Current growth rates and predicted growth rates are well above normal
  • Growth rates are much higher than demand leading to huge increases in AFC (This week Growth 77 vs Demand 57 = 140kg DM/ha increase in AFC per week)
  • AFC targets should be 600-700kg DM/ha, currently 798kg DM/Ha on dairy farms
  • Wedge – too many paddocks above demand line set at 1,400kg DM/ha PGY
  • Demand can be increased by reducing meal feeding, reseeding, removing paddocks for surplus bales, bringing animals back to main grazing platform
  • Remove surplus immediately this week and get paddocks back into the grazing rotation.

For more tips and advice on Grassland management, visit the Grass10 webpage.