Dairy Management: avoid an April grass surplus

Grass growth rates have jumped significantly over the last few days and farmers can see the changes in the fields before their eyes.

It’s a great time to be a farmer and to be able to experience the change in the seasons as we move to late spring and early summer.

Growth rates at this time of year can be notoriously unpredictable. Most farmers will plan for growth to increase around now, but there’s no guarantee that it will come.

Equally, there is every chance that if the weather turns cold for a week growth rates could drop again later in April.

However, we can only make decisions based on the information available to us at any one time and now, its looking like growth rates will be improving daily for the coming week.

Now that grass is beginning to motor, particularly on farms in warmer areas in southern counties and on farms that have been well fertilised, action will need to be taken to avoid a big grass surplus in April.

This is a big risk and it creates a lot of problems because before you know it, over half of the farm could be unsuitable for grazing.

This is a problem that happens when covers go out of hand because supplement was left in for two long.

The supplement I’m referring to here is silage and high rates of meal. Problems with too much grass in April can be traced back to poor decisions in late March and early April.

The ideal average farm cover at this time of year is around 550kg DM/ha. The only justification for feeding silage now is on farms where farm cover is much lower than this or demand is very high due to a high stocking rate.

If growth is exceeding demand, or if farm cover is much higher than target, continuing to reduce grass demand by feeding silage or a lot of meal will mean that farm cover will continue to increase.

The ideal farm cover in early to mid-April is around 160 to 180kg DM/cow. This is average farm cover per hectare divided by the stocking rate.

If farm cover goes higher than this, land can be taken out for silage and reseeding but the area available for the cows still needs to be big enough to sustain a 21-day round length with 2kg or 3kg of meal.

The risk now is that if farmers are slow to remove supplement, and keep cows in on silage by night, or keep feeding 5kg or 6kg of meal that average farm cover could go 300kg/cow quite easily.

This would mean grazing covers of 1,600 to 1,700kg which is too high. In order to rectify this, too much of the farm will have to be closed for silage.

The next consequence of this is the grazing area available to the herd becomes too small and if a week of depressed growth rates comes in late April, the farm could go from having too much grass to too little grass.

Best policy is to keep on top of changes by walking the farm regularly and removing surplus whenever you can in order to increase demand.

This is a much better policy than to keep feeding and close up ground first. It’s easy to put the supplement back in if you need it.

Closing up too much ground in April is risky. Aim to close up long term silage ground, but try and avoid too much surpluses other than that.