During the second half of August, grass growth will start to slow on many cattle farms and, as such, thoughts should be turning to building grass for autumn grazing.
While grass growth should exceed livestock demand during August, growth rates will fall below daily demand at some point in September.
This means cattle will be eating through swards faster than grass can regrow. Following the outlined steps will help maximise grass growth over the coming weeks to extend grazing into late autumn.
Make sure all grazing swards are fertilised once cattle are removed in the current grazing rotation. Use a chemical fertiliser to drive grass growth at this point of the season.
Don’t rely on slurry to supply nitrogen. Slurry spread in late summer or early autumn will provide very little nitrogen to the sward.
Apply 25 to 30 units/ac of nitrogen, ideally with some phosphorus, potassium and sulphur. Include any silage aftermath in fertiliser plans.
Use silage ground to increase grazing area
Hopefully, silage will be finishing up on most farms by mid- to late August. As this ground becomes available for grazing, it will help lengthen rotations and give more time for grass covers to build.
Alternatively, in a more set-stocking situation, silage ground can be used to spread cattle out over a bigger area, reducing the demand on older and less productive swards.
Leaving higher grazing residuals
As grazing moves from late summer into autumn, avoid grazing swards out tight to ground.
Leaving a slightly higher residual cover means there is more leaf present to capture sunlight. This increases the rate of regrowth after swards have been grazed.
There is no issue with grass quality at this time of year, so leaving a higher residual will not impact on sward quality in the next rotation.
Extending rotation length
By the end of August, the aim should be to have between 25 and 30 days of grazing ahead of cattle on each block. This should see cattle comfortably grazing into the final week of September.
The regrowth that comes back on grazed paddocks during September will carry cattle into October and, weather depending, housing time.
Reducing grazing demand
Another way of building grass ahead of cattle is to reduce the grazing demand. This can be carried out using a number of methods.
Firstly, the live ring is extremely strong at present, so give thought to selling stores carrying plenty of condition during late August, rather than late September or October.
Offloading other cows marked for culling as early as possible will also reduce grazing demand
Scanning spring-calving cows early will identify empty animals for sale. Cows can be accurately scanned around 40 days after service.
Empty cows can be offloaded through the live ring while they are in good condition, either as a cull or with a calf at foot. Offloading other cows marked for culling as early as possible will also reduce grazing demand.
Introducing concentrate to autumn-calving cows, stores and spring-born calves will also reduce the demand for fresh grass in early autumn.
Finally, housing forward stores for a short intensive finishing period on high-quality, high dry matter silage and concentrate will also free up more ground for other stock, again reducing demand.