Making the most of summer grazing

by Katherine Byrne, GippsDairy

It was a good spring across Gippsland, but as the summer heats up there are still plenty of opportunities to maximise the benefits of a favourable season and prepare your pastures so they can bounce back in autumn.

With rainfall becoming more sporadic as we move in to the New Year, the management of residuals become more important than ever.

The key points for managing grazing residuals over summer are:

• Do not over-graze. Maintain the residuals at 1,500 kg DM/ha (4-6 cms). Cows tend to graze down to 1,200–1,300 kg DM/ha over summer, so grazing will need to be restricted.
• Aim to maintain some green material over summer (e.g. green stem, pseudostems), as this will help summer survival and autumn regrowth to build the feed wedge.

The presence of some pasture cover by maintaining residuals at around 1,500 kg DM/ha creates a more favourable micro climate near the soil surface than when grazed down to around 1,200 kg DM/ha. The micro climate can help retain soil moisture close to the surface and create protection from extreme soil surface temperature.

Achieving these aims can be challenging on dryland dairy farms with high stocking rates when the summer rainfall and temperature are not sufficient to support pasture growth.

As the temperature starts rising, but there is still actively growing pasture, some techniques to consider are:

• Get the cows onto available pasture before the temperature rises. This may mean milking earlier in the morning in order to get the cows onto their daily pasture allocation earlier. By doing this the cows will eat more of the offered pasture before the heat starts to affect their desire to graze. Alternatively, some farmers prefer to milk the cows later in the morning based on the assumption that the cows will graze more pasture before they come in to milk (and supplement will be fed to them during the day in a shaded area).
• Offer the cows a larger part of their daily allocation at night. They are more likely to graze harder at night when it is cooler.

In situations where limited pasture is available, strategies include:

• Keeping the cows in a reduced area (sacrifice paddock) where they can be fed and only access the pasture paddocks to consume the allocated pasture, allowing for a residual of around 1,500 kg DM/ha (4-6cms).
• Identifying paddocks suitable for use as sacrifice paddocks. These should have good stock water access, good shade, proximity to the dairy and have been previously identified for renovation.
• Feeding out in the sacrifice area. Cows will be less hungry when entering a new strip of grass, making it easier to control the grazing intensity and leaving a residual close to the target.

Supplement use is another key part of successful summer grazing strategies. If it is too hot for the cows to graze the open pasture, then it may be far more profitable to feed them supplement in a shady area during the heat of the day.

The daily pasture allocation can then be offered to the herd at night when they are more likely to eat it.

To learn more about pastures and allocation, put your name down for the next Feeding Pastures For Profit program commencing in March 2022. For more information please contact Katherine Byrne at Katherine.Byrne@gippsdairy.com.au