Add two days to your grazing rotation
Published 17/08/2016 | 02:30
Building autumn covers of grass can be a tricky business. If you don't build enough grass, cows will end up eating too much expensive meals and silage in the month of October. And if you build up too much grass then you run the risk of leaving a butt of old grass through the winter which is a waste of good feed and will also impact heavily on next spring's grass quality.
With milk prices being where they are, it is vital this year that the majority of our autumn milk is produced off grass. Grass costs 7c/kg to produce, silage 15c and meal 25c approximately, so obviously we want as much as possible of the stuff that costs 7c in our cow's diets this autumn.
Grass growth generally tapers off at the end of August, typically dropping below 60kgs growth per day, and it further tails off further as we head into October, dropping to below 40kgs per day. Therefore, the grass we graze in October/November has to be grown in September and this won't happen by accident.
Rotation length needs to increase by two days per week from now on.
Most farmers try to determine the rotation length by trying to remember when the cows were last in today's paddock, which gives a good indication, but a better way is to divide the amount of ground the cows are eating on a daily basis into the total ground available. If you have 100ac available for the cows and they are eating 4ac per day, then your rotation length should be 25 days. At the end of August they need to be eating only 3.3ac per day.
Adding two days per week to the rotation length can happen in two ways - increase the supply of grass or reduce the demand.
Increasing grass supply