Magic Day

Published 17 May 13

We've had some higher grass growth rates in the past week or so from some of the farmers who are taking part in our Forage for Knowledge grass analysis, says Piers Badnell, DairyCo Extension Officer.

"Soil temperature and moisture levels seem to have come together to provide better long awaited growing conditions. And what this means is, that in some areas, Magic Day is here or soon to be here, even if it is a month later then normal!

"Magic Day is the day that grass supply matches grass demand," explains Piers Badnell. "It means you have to start managing your grass in a new way. It's the start of a new regime.

"Grass growth rates are finally increasing so you have to be on top of your management in order to make sure the grass does not get away from you, and quality suffers. Grazing surpluses should be conserved. If the next field is getting away from you skip it and move to the correct entry of 2700 - 2800 kg DM / Ha. It is very important to maintain grass at the correct entry covers, but in a year where silage is going to be lower in yield than usual the ability to conserve what you can't utilise now but are able to utilise as silage later, is a double bonus.

"Grass that gets beyond 2800 and certainly 3000 kg DM / Ha is growing slower, thus reducing your overall yield, and it is reducing in quality. It is also harder for the cow to graze and utilise and so it gets wasted.  

"It's after magic day that it's all important you manage the grass using the grass wedge.  The wedge allows you to spot potential surpluses or shortages in forage supply in the near future. Using the  wedge gives you ten days to two weeks' notice of what is happening in terms of growth speeding up or slowing down. It gives you time to put measures in place to rectify the situation, before things get away from you in terms of having too much grass in front of cows, and thus increasing waste. Or conversely with grass growth slowing and potentially cows chasing grass and getting ahead of supply, with the end result of no grass and the resultant cost implications of feeding cows from the pit or lorry.

"On a recent farm visit with a grassland group, it looked like the host farmer might well be heading towards having a grass surplus and we talked about what steps he was going to take to help get grazing back on track," says Piers Badnell.

"The farmer is going to increase the grass allocation to his low yielding cows to 15kg DM and possibly look at increasing the grass in the high yielders diets after a conversation with another member who has been able to make use of the high dry matters in grazing to increase dry matter intake to 9kg DM per cow. The conclusion of the group was to measure the grass weekly and reassess the situation to try and make sure they are one step ahead of it.

"Even with Magic Day approaching it is important to remembe there might not always be plenty of grass. Especially in areas where night time temperatures are below where we would normally expect with the resultant suppression of grass growth.

"Grass growth varies through the season, and with the ability to measure and budget with a plate meter and the grazing wedge, managing the rapid increases in growth and then the slowing up enables good profitable decisions to be made."