15 August 1997

Surplus advice as grass jumps ahead of stock

By FWlivestock reporters

HIGH grass growth rates across much of the country should be managed by increasing stocking rates and taking surplus for silage to maintain sward quality and intake potential later on.

Most farms are growing far more grass than stock are eating, says New Zealand consultant Paul Bird (see Grass Watch, p38).

Good quality ryegrass in a leafy dense sward could support 20 litres a cow a day this month, depending on stage of lactation, he says. But grazing mature grass will restrict production from forage.

"Grass has got ahead of stock. Have confidence to jump ahead to grass at the optimum cover for grazing to maintain grass quality and production. What to do with the surplus is a secondary issue."

He suggests ensuring quality grass for September by grazing down hard. Alternatively, go in with a mower and bottom the pasture to eliminate seed heads and stalks, he says. Excess grass could be cut for silage, kept for dry cows, or the lower quality grass could be deferred and strip grazed by dry or late lactation animals when grass growth declines later on.

New Zealand consultant John Simmounds also warns producers against leaving high residuals – more than 2500kg DM/ha – behind after grazing. This will compromise the quality of autumn grass.

Although pasture clean out is not critical on a day-to-day basis, he says pastures should be tidy by late September to avoid winter kill.

"Producers with autumn calving herds should use dry cows to manicure pastures which are a mess; strip or block graze graze down to 1000kg DM/ha. Where eating power to clean up after cows is limited then consider mechanical means, he says.

He advises aiming for a target grass cover across the farm of 2400-2500kg DM/ha. If its over that, skip paddocks from the grazing rotation and take these for silage.

"But if you cant eat it today, mow it tomorrow. You want paddocks growing grass again to avoid a feed deficit later on when grass growth falls."

Beef producers should aim to maintain swards at about 10cm (4in) to ensure there is enough grass for autumn grazing when set stocked herds traditionally face shortages, says SAC beef specialist Basil Lowman.

Where swards are at more than 10cm, and are getting ahead of cattle, consider conservation or shutting some off for later use.

"Consider conserving grass, but remember that its no use making silage if it means grazing will be short in autumn and that silage has to be fed to maintain growth rates."

A better option may be to shut up some grass for later use, says Dr Lowman. "This can be used when grass starts to run short. Mowing grass and grazing will reduce poaching, maintain intakes and cattle growth rates."

Welsh based dairy consultant Andrew Crossley is advising clients who have surplus grass to attempt to cut rather than graze longer aftermaths to make some better quality forage than that in store.

"I have seen dry matters of below 20%," he says. "If a producer does not know this when estimating whether they have enough silage their cows could be licking the back wall of the silo before the end of March."

Conserving as big bales could be a better option than clamping as the flexible system allows small areas of grass to be used.

MANAGING SURPLUS

&#8226 Graze down tightly

&#8226 Skip some paddocks

&#8226 Silage the surplus