Making the most of new grasses

Hawke's Bay father and son John and Duncan Gray can't afford to have livestock falling over with ryegrass staggers every summer. 

With 5500 stock units on 506ha of staggers-prone country near Waipukurau, safe grazing is a necessity, not a luxury. 

Which is why John and Duncan have been renewing runout paddocks with AR1 endophyte pastures since 2000.

"We did try one new paddock without AR1 (using Standard endophyte), but the stock fell over on it, so we didn't do that again," Duncan says. 

The pair runs bull beef, trading steers and Romney ewes and lambs under a fairly intensive grass-based system that concentrates on achieving maximum productivity from the farm's best land.  

This comprises about one-third of the Grays' total area, and has been progressively tipped over into modern, high producing pastures during the past 12 years. 

Some paddocks sown with earlier varieties are now being renewed for a second time to maintain high productivity and carrying capacity, Duncan says. 

Key elements of this successful regrassing policy are the use of summer crops; twice yearly fertiliser applications, and a stock management policy that maximises the longevity of new pastures by protecting them from over-grazing, and from winter damage. 

John's only partly joking when he says they've tackled renewal ‘like a dairy farmer' by using the right new varieties on their best land, and feeding them really well. 

Picking the right pasture options has involved much trial and error, as well as the help of PGG Wrightson rep Rex Newman from Waipukurau. 

"If you don't try something, you don't know how it will go.  We've tried heaps of new grasses here," John says. 

Their current perennial ryegrass is Bronsyn Plus AR1, with Apex and Sustain white clovers.  The oldest paddocks in this mix were sown in 2005, and have thus faced some challenging seasons. 

Duncan says Bronsyn's mix of AR1 staggers-free grazing, palatability, high yield and general toughness has stood up to their high stocking rates as well as their climate. 

"It's a good all-round pasture for us.  And it was the only thing that stayed green and grew through the drought, with good recovery afterwards."

Because of their stock policy the Grays need good feed year-round.  Soils on their rolling land are sedimentary (red metal and some limestone); annual rainfall historically averages 1000 - 1200 mm and the farm is relatively summer safe for Hawke's Bay, so they are stocked up most of the season. 

Their mix of high-producing pastures and summer crop - plus baleage - means they can winter 120 R1 dairy-beef bulls, plus 250 R2 beef steers, two thirds of which are Angus with the rest exotics.  A small number of R2 bulls (perhaps 30 head) is also carried through each winter. 

The bulls are bought in at 100kg and finished to target kill weights of 300-360kg.  Steers bought in at 18 months are typically quit at 330-400kg, depending on the season. 

The Grays' flock of 2500 Romney ewes averages 138% lambing from mid-August, with the first drafts taken off mum at weaning on December 1 (average kill weight 16kg). 

The bulk of the lamb crop is drafted for slaughter off summer crop, averaging 19kg, and the final 200-300 are carried through winter. 

Integration of sheep, steers and bulls gives the Grays a great deal of flexibility when it comes to their grazing management, allowing them to look after their best paddocks by grazing different classes of stock on them at different times of the season. 

Carry-over lambs, for example, are grazed on new paddocks of Bronsyn Plus AR1 during winter, then set-stocked with ewes for lambing at 13su/ha, and the bulls come on to them in late spring when growth gets cranking. 

"This also helps break the worm cycle," Duncan says.  "So there's less drenching, and less yard work with the bulls and less dags on the sheep.  It also improves the life of our pasture."

Good growth in spring is essential to get the bulls growing rapidly after winter.  During September 2008, when warm air temperatures combined happily with ample soil moisture from heavy winter rain, grass growth rocketed and liveweight gains reached 2.5 kg/head/day (average rates are 1.8-2 kg/head/day).

As of late November, with no appreciable rain for two-and-a-half months, the Grays like many in the Bay were eyeing up the prospect of another drought with some concern, but new pastures had been so well managed through spring seed heads were only just emerging on the Bronsyn paddocks, three to four weeks after it would normally be expected to flower. 

"We do try to keep right on top of the growth," Duncan says.  "The bulls are not over stocked at 2.5-3 head/ha in spring and we'll add steers for extra control if we need it.  If all else fails we'll get out the mower."

About 25ha of summer crop is sown each spring, for both lambs and bull calves, which start arriving on the farm from November. 

Once the crop is grazed, the paddocks are limed, cultivated and sown with new grass and clover seed in March and April.  Fertiliser is applied by truck at 300kg/ha sulphur super.  Six to eight weeks after sowing, when the grass is 12cm high, the Grays ‘chew it down' with ewes to stimulate growth and firm the ground. 

In spring they apply DAP at 150kg/ha and thereafter the new grass paddocks are dressed biannually with maintenance fertiliser of 300kg/ha sulphur super, and DAP. 

This is essential for survivability, John and Duncan say, as is maintaining good covers.  "You have to be careful not to overgraze it at certain times of the year, which has been hard in the last three years."

Published courtesy of Country-Wide - January 2009