Aber® high sugar grass best for pasture renewal
A leading South Australia dairy farm milking 2,300
cows has chosen an AberHSG high sugar grass for its pasture renewal
following an on-farm growing trial and laboratory tests.
The results of lab tests and a year-long grazing trial were
required by Donovans Dairying Company before committing to any new
grass for resowing five-to-10 percent of a 715-hectare milking
platform each year.
"The seed companies do provide data but we wanted to see for
ourselves what ryegrass will work best for us," said farm manager
Jim Simpson. He said the higher sugar content, as claimed for both
ryegrass cultivars chosen for the trial, was an appealing quality
as it could remedy high nitrate levels in their pasture and cows,
which causes scouring and reduces their conception rate.
A further motivation is to intensify their stocking rate while
allowing for more land to be used for maize silage and other forage
crops. "We currently have pasture ten to eleven years old that has
performed well enough but which has limited us," said Jim, who has
managed the property on the Limestone Coast south of Mt Gambier for
five years. A significant change already made by his team of 20
staff is to apply less urea fertiliser. "We have had a rethink
about productivity," said Jim, farming since he arrived in
Australia as a young history graduate from Wales looking for a
change of lifestyle. "Instead of targeting 20 tonne of drymatter
per hectare per year and the cows eating 16 tonne, we are now
targeting 16 tonne and the cows consuming about 14 tonne of better
quality feed," said Jim.
The outcome of the trial is already evident in the 32ha of
AberDart sown at the start of January with the plan being to sow
more at the start of each year. In their on-farm trial, the cows
began grazing the diploid (perennial) cultivar AberDart from
mid-February last year along with a tetraploid cultivar sown in the
other half of a 16 hectare block under pivot irrigation. Jim
observed the AberDart to be a denser ryegrass with fewer weeds in
the sward and appearing likely to withstand more stock traffic than
the open growing tetraploid cultivar. "The AberDart's dense, fine
tillers means that under irrigation there is less bare ground and
that should mean more water absorption and it catching any dew."
The cows showed a strong grazing preference for AberDart when being
allowed unrestricted access to both ryegrass cultivars. "They did
seem to eat the AberDart more," said Jim, who decided for the third
grazing that the cows had to be fenced into the tetraploid area to
graze it off and ease the grazing pressure on the AberDart half of
the paddock.
Managing one of Australia's biggest pasture-based dairy herds
and producing up to 22 million litres of milk a year from cows that
yield twice the national average, Jim said he will be looking for a
correlation between AberHSG ryegrass and milk yield from their
spring and autumn calving mobs. An increase in milk yield looks
achievable as the extra sugar in AberHSG ryegrass is known to boost
rumen function and therefore increase nitrogen use efficiency - the
bottom-line being that more grass is converted into animal protein
and there's less nitrogen waste. Advantage Ag general manager Rick
Jordan, whose Mt Gambier farm consultancy organised the trial and
analysis by two independent laboratories, said the aim was to
determine the suitability of AberDart under local conditions.
AberDart was chosen for the trial after a presentation by South
East Seeds Pty Ltd (supplier based in Naracoorte), Specialty Seeds
Australia Ltd and Germinal Seeds NZ Ltd, who were able to refer to
its performance on farms 120 kms east of Donovans at Yambuk, where
on one farm it's growing through a third summer as dry-land
pasture. "AberDart data shows much more improvement for longevity
and yield and the data sets highlighting increased WSC (water
soluble carbohydrate) levels appealed to myself and our farmer
collaborator in the trial as being a viable option to pursue," said
Rick. The lab results showed that AberDart did in fact have more
WSC than the tetraploid ryegrass and had similar levels of crude
protein (CP), although AberDart was calculated to have "higher
effective dietary protein", he said. "It was worth noting that the
AberDart also tested higher for drymatter percentage in a number of
tests but lower in NDF percentage (neutral detergent fibre)."
Less fibre in a ration enables an animal to eat more, reduces
the time required for rumination (digestion) and is linked to a
higher energy concentration - all important benefits. Rick Jordan
said they were also impressed with AberDart's ability to rapidly
re-establish tiller density after a delayed silage cut during
spring. "Other farmers in similar environments and under intensive
management regimes could and should consider AberDart as an
effective pasture base option for their enterprise where high
yields from optimising inputs are being targeted," he said. While
Rick had yet to see AberDart's longevity tested in the Mt Gambier
environment, Jim Simpson said it was likely to grow through their
summer heat after coping with an extreme heat wave of 35°C days
this past spring. Its dense root growth in the farm's thin topsoil
was a further indicator of persistence.
Contacts:
Laurie Meyer : Specialty Seeds Australia Ltd
Phone: +61 352 645 108
Mob: +61 419 335 225
Email: specseed@bigpond.com
Web: www.specseed.com.au
Steve Searle : Searle Communications
Phone: +64 7 871 6805
Mobile: +64 21 03333 04
Email: steve@searlecomms.co.nz
