Grass Challenges: Matching Supply and Demand

28th June 2024

Widespread unpredictability in weather across NI to date has presented a number of challenges for grass management this grazing season; persistent rainfall in early spring resulted in an undesirably later turnout for most grazing herds with entry covers well in excess of the optimal 3000 kg DM/ha, whilst current weather have introduced additional challenges for grass regrowth and quality.

Grass growth for June peaked in the region of 70kg DM/ha – 10 kg DM/ha behind last year, with the 10-year average significantly ahead at 85 kg DM/ha.

Similarly, grass quality has been impacted with GrassCheck plots indicating below-average crude protein and energy values:

As a result, full-time grazing herds have been struggling to maintain milk production; lighter entry covers due to slower regrowth and/or wet grazing conditions will significantly reduce dry matter intake.

Therefore, it is important to factor these implications and make allowances to match supply and demand of fresh grass.

Measure or walk paddocks weekly to assess grass growth:

  • Target grazing cover = 3000 kg DM/ha or 10cm height
  • Target residual cover = 1500 kg DM/ha or 4cm height

Over Demand:

  • Consider buffer feeding cows with forage before evening milking or housing cows at night to conserve grass and ensure target dry matter intakes are met.

Over Supply:

  • Consider removing some paddocks from the grazing rotation for baling; can be used for buffer feeding at a later stage if required.