Q. What if conditions are wet for weeks?
A. If you don’t have a feed pad, do as much as you can to avoid damaging the pasture. Here are some tactics you can use:
- Graze the first break of several paddocks to limit the number of times cows move through each gateway.
- Put supplements in the paddock before the cows arrive. This reduces stock movement and pasture damage when it’s wet.
- Allocate bigger areas (a faster rotation) – this is okay as long as you can slow it down when it’s not raining.
- Of course, if you have a stand-off pad, use that.
Q. What if winter growth exceeds expectations, leaving me with high pasture cover?
A. One of the nuances of this scenario is that high winter growth and high pasture covers at calving could result in a slower-than-average spring growth rate. This is because nitrogen has been used up growing grass in the winter, and pastures could be slower to re-grow because they’re more open as the base has been shaded. That’s why you should use DairyNZ’s Spring Rotation Planner (dairynz.co.nz/SRP) to allocate pasture appropriately until you’re sure you have the growth rates and the cover to move faster. If necessary, apply some nitrogen to fill any projected deficits.
Q. What if pasture growth is below target?
A. Don’t speed up the rotation; stay on the allocated area per day as long as you can, and keep an eye on your residuals. If they’re getting too low, use supplements to feed the cows and apply nitrogen fertiliser to boost growth.
Q. What if the area allocated by the Spring Rotation Planner doesn’t give me enough pasture?
A. Your cows are the best judge of how well you’ve assessed the pasture yield. They’ll indicate to you, through the grazing residual, if it’s consistently wrong. If you think your residuals are too low and cows are underfed, before making a decision, measure the residual first (with a plate meter) to make sure. If it is low (1400 kilograms of dry matter/hectare or less), you can increase the area of pasture offered in the next break, provided average pasture cover and rotation length are high enough; or you can feed available supplement to fill the deficit and stay with the same area of pasture.
To learn more about pasture management from calving to balance date, go to dairynz.co.nz/spring
This article was originally published in Inside Dairy August 2019