The grazing season really begins in autumn as what you do now will influence grass supply on your farm in the spring. Each one-day delay in closing your farm’s grazing platform after October 15th has been shown to reduce spring grass supply by 15 kg DM/ha, therefore autumn grazing decisions will directly impact grass availability come next spring.
The objective for many farmers is to maintain grass in the diet for as long as possible, while also ensuring the farm will have sufficient grass available next spring, when it is hugely valuable on farm. With this in mind, thoughts should have now moved to autumn closing of the grazing platform, if not already underway.
Your soil type and location will have the greatest influence on your target closing date. Higher stocked farmers and farmers with heavy land will have started closing paddocks in rotation from early October while drier less densely stocked farms will have more time on their side.
A good reference tool is a 60:40 autumn rotation planner to see out the rest of the grazing season. The 60:40 rule states that 60% of the farm should be closed by the end of the 1st week of November and fully closed by late November, or at closing, has a farm cover of 550-600 kg DM/ha for those stocked at 2.5 LU/ha; whichever comes first.
The target is to have a grazing residual of 3.5 to 4 cm to ensure light reaches the base of the sward and minimises tiller death over the winter. Again, for higher stocked farms, you will need a higher closing residual and be aiming for nearer 70-80% of the grazing platform closed by early November, remembering that paddocks closed after this date will not be grazed again until next spring.
Don’t be tempted to go back and graze closed fields; even if grass growth remains strong. What is grazed now won’t be available in the spring, and each day delay in closing will reduce farm cover by 15 kg DM/ha next spring.
Best advice is to monitor grass and farm cover on an ongoing basis and close the farm when above mentioned targets have been achieved.
What the closed paddocks will look like next spring
The earlier closed paddocks may well be the later grazed ones come next spring. This will be due to the presence of too much grass at time of turnout and, if this is the case, they should ideally be kept for February/March time when cows have adapted back to grazing and their appetites have started to rise. The paddocks closed later on in the autumn grazing season should be targeted for early spring grazing and therefore, if achievable, these should be the drier paddocks close to the yard.
Other autumn grazing/closing tips
- Poorly grazed fields in autumn will result in decaying material over the winter and this will have a negative effect on spring grass supply, so this should be avoided.
- Block grazing and back fencing are useful tools. Use a strip wire and moving animals once a day will improve utilisation.
- Heavy cattle that are to be finished over the winter should be housed first.
- Closing cover should be approximately 600 kg – 650 kg DM/ha while spring opening cover should be 750 -800 kg DM/ha.