Grass Watch 18


Grass Watch 2018

Grass Watch is designed to demonstrate the value of grass in milk production and the impact this variable food source can have on key components such as butterfat and Protein(%).
This key information on grass quality can help shape a feeding programme to achieve the results of a modern day high yielding herd. Samples are taken Weekly every Monday from the Paddocks the cows are grazing and are sent off to be analysed. Several monitor farms are used locally and are combined to achieve average. Programme runs until November.
The Map to the right shows the 15 Areas in which are collector sites to generate the results displayed below. Please note that the Map pins are not exact and are only used as a general guide to the area in this programme.

GrassWatch summary update: Week 32 (Aug 6th) 

Grass quality has declined over the past few weeks with fibre content of swards increasing and proportion of rapidly fermentable carbohydrate decreasing – hence butterfat alert indicates low risk of milk fat from acid load and fibre index. However oil content and RUFAL (rumen unsaturated fatty acid load) of grass remains high, therefore butterfat alert continues to indicate high risk of milk fat drop.


Grass crude protein has continued to rise this week, with NFEPB (NutriOpt Fermentable Energy Protein Balance) value consequently increasing – illustrating the increasing oversupply of rumen degradable protein relative to available rumen degradable energy in grass. This imbalances results in excess rumen nitrogen. The energy required to deaminate this excess rumen nitrogen corresponds to  an energy loss equivalent of 1.4 litres/cow/day of milk this week. Grass high in nitrogen is often ‘sour’ and hence unpalatable to cows –  hence getting swards grazed out well can be a challenge at the moment.

With grass growth doubling over the past week, it’s important to be pro-active in identifying and pulling out surpluses early.

Tips for managing grazing:

  • Continue to hold at least a 30 day rotation to allow grass covers to recover
  • Walk the grazing platform at least once per week to monitor grass supply
  • Ensure residuals of 4cm are still being achieved – this may become a challenge as grass can be excessively high in nitrogen at the moment, making it less palatable to cows.
  • Continue to sow at a rate of 25-30 units of nitrogen per acre on the grazing platform. Where fertilizer application ceased on some farms over the drought period, blanket spread the entire grazing platform with 25-30 unitsN/acre.
  • Phosphorus (P) will be essential in root recovery after the drought, therefore where farm Phosphorus balances allow, application of compound fertilizer containing phosphorus should be considered. Application of potassium and Sulphur may also aid in sward recovery

The dry matter (DM) content of forage (measured as a percentage) is the proportion of total components (fibres, proteins, ash, water soluble carbohydrates, lipids, etc) remaining after water has been removed.
Knowing the dry matter percentage of forage is important. The lower the dry matter content, the higher the fresh weight of forage required to achieve a target nutrient intake, whether this is grazed grass or conserved forage.

In Ireland, due to the climate, we typically have very low grass growth rates in the spring and again in the autumn, with maximum growth rates being achieved during the month of May. Although there is little we can do about the weather in the spring and autumn periods, there are a number of measures we can take to improve grass production at the shoulders of the season.

If you would like to be updated with the latest results fill out the below contact form and we will keep you up to date.

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Weekly Dry Matter

Predicted Milk Yield From Grass Only: Based on Average Grass Energy

Compound (kg/d) based on Average Grass ME

14kg DMI

Crude Protein %

Oil Process A

ME     (MJ/kg)


Sugars – Fresh

Turnout – Getting More From Grass

Short informative video on key essentials to maximizing yield from grass systems.

Weekly Grass Growths (PastureBase Ireland)

Weekly Grazing Information

Weekly Grass Growths (PastureBase Ireland)

Weekly Grazing Information