Farm Ireland

Monday 22 January 2018

Assess grass cover levels

The right combination of heat and moisture has provided perfect growing conditions for grass over the past week, and most farms have moved from a shortage to a surplus of grass.

It's a great complaint, but prompt decisions are needed to manage a surplus and keep the quality of the grass high. Decisions taken now influence the rest of the grazing season and these decisions should be based on an accurate assessment of the grass covers on the farm.

More farmers are using tools such as the pasture wedge graph to help them manage their grass cover, and the increased number of farmers in dairy discussion groups means that more are learning how to measure grass and make decisions based on covers.

Using the pasture wedge graph is a good way of identifying if you are in surplus and which paddocks need to be taken out of the rotation and cut for silage. The wedge should be completed on a weekly basis to estimate the cover on each paddock.

It can be drawn up manually or on the computer and gives a good visual representation of the amount of feed available. Your challenge, once the graph is completed, is to interpret the information.

Ideally, you should aim for pre-grazing covers of around 1,400kg DM/ha. This will help to maintain leafy grass of high quality with less stem. Keeping swards leafy will help to keep up the protein in the milk.


Many farmers, though, continue to turn their cows into paddocks with too much grass throughout the main grazing season. This results in poorer cow performance and increased topping costs. Grazing lower covers mid-season is important. Every farm will have a different pre-grazing cover target, which is related to your stocking rate. Talk to your local Teagasc advisor for more details.

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There is evidence that proteins have dipped for many producers. All the research proves that improving the quality of grass in front of cows will increase milk protein and result in up to two litres additional yield per cow per day.

The lift in growth rates is also helping to bulk up silage crops, increasing the potential yield. Some crops had been looking very light and slow to build up, but that has thankfully changed over the past fortnight.

Some farmers are knocking crops already as the first days of June beckon, and the quality of silage should be good. Holding on for another week to let crops bulk out may suit your farm, but remember that, while each week delayed harvesting will increase quantities in the pit, it will have an impact on quality, and DMD will begin to reduce.

It's a balancing act between quantity and quality, but there is scope to hold for a week or 10 days without taking risks with silage digestibility.

Irish Independent