Caption: Farmers at last month’s field day on David and Erin Gunson’s Northland
property heard how the Gunsons had managed to lift meat production from around
200kg/ha to 300kg/ha over the past five years.
Caption for heifers: Calving dates have been progressively shifted back on the Gunson’s
property. The herd now starts calving on December 20.
Hugh Stringleman
Feeding increased numbers of sheep and cattle as part of a nitrogen project has
brought challenges for Northland farmers David and Erin Gunson.
One of 14 farms nationwide in the hill country farming project, the Gunson’s
Waikiekie property near Waiotira received an average of 108kg N/ha this year.
The farm is 422ha with 370ha effective, with 60% medium hill country and the
remainder split between easy/rolling and steep hills.
The highest rates of application were up to 132kg on the intensive beef unit and
the twin-lambing paddocks. All nitrogen was applied with three or four spreadings during
June to November.
In recent years the nitrogen use has been about 30kg/ha.
Stock numbers have been increased to utilise the anticipated feed.
More than 1000 extra sheep were wintered and between 60 and 136 more cattle,
depending on timing, when compared with the two previous years.
On July 1, 2005 the Kauri Glen property carried 2740 sheep, compared with 1740
the year before. Breeding ewes went up from 1100 to 1232, ewe hoggets from 325 to 505,
wether hoggets from 300 to 380 and 593 trading ewes were purchased, which is a new
stock class to the farm.
The cattle numbers on July 1 were 665, comprising 124 breeding cows, 71 R1yr
heifers, 397 R1yr bulls, 67 R2yr bulls and 6 breeding bulls.
The production and financial analysis of the stock numbers and finances showed
that EFS has varied between $450 and $600/ha over the past five years. The Gunsons
want it to be consistently over $550/ha.
Meat production from the farm has risen from around 200kg/ha (Northland
average) to 300kg. This has been done by intensifying beef management so that more
bulls can be wintered, increasing the subdivision, raising the sheep reproduction rate with
Finn sheep, using summer crops for lamb finishing and ewe hogget growth and
strategically applying low rates of nitrogen.
The aim of the wise use of nitrogen project is to get meat production up to
395kg/ha and the gross margin up from $670/ha to $900.
To do this, the Gunsons are introducing winter trading stock options, increasing
sheep numbers to equate to 50% of feed demand, boosting stocking rates on the lambing
platform and cranking up the intensive beef system.
AgResearch scientist Greg Lambert, the designer of the wise use of nitrogen
project, and Northland farm adviser Bob Thomson also want the Gunson experience over
the three years to be demonstrably sustainable.
However, the Northland weather is never predictable particularly in the spring.
David set-stocked the lambing platform with 12 to 17 twin-bearing ewes per
hectare, up to twice the stocking rate used before. Those areas also carried a cow to the
hectare.
The Farmax model came up with that much higher stocking rate based on the
strategic use of nitrogen. The lambing platform had 46kg N/ha on August 15, and 30 kg
N/ha on either October 15 or November 15. It is scheduled to have a 40kg application in
autumn.
The lack of rain right through until June, followed by a mild winter and a very wet
October, when the nitrogen application was a month late, adversely affected lamb growth
rates.
David responded by mobbing up the ewes with lambs and started a rotation to
build some feed ahead of them. But this was a rescue job.
At the late November field day David said he expected to wean in early
December, at shearing time, and have to sell some smaller store lambs.
Lamb growth rates from twinning ewes between birth and docking (late October)
ranged from 190 to 220g/day. Some of the terminal-sired lambs achieved 225 to
290g/day. These rates were all less than the 300 grams targeted.
This is in contrast to spring of 2004 when the Gunsons were one of three farms
participating in a Farmer-Initiated Technology Transfer (FITT) programme aimed at
30kg lamb weaning weights.
The programme demonstrated that 30kg weaning weights are possible at 12
weeks, although in the Gunson’s case this was achieved at 14 weeks.
The treatment area received 37kg N/ha at set-stocking, in late August, and another
37 kg N/ha at docking, in early October.
The lamb growth rates on the treatment area were 308g/day for birth to docking
and 208g/day from docking to weaning. The average weights were 15.2kg at docking and
29.3kg at weaning.
The objectives were to market half of the male lambs and 30% of the terminalsired ewe lambs at weaning when the market prices are higher and to get ewes back to
tupping weight at lamb weaning.
As well ewe lambs would be well on the way to 45kg target mating weight by
May 1.
The FITT trial also demonstrated that more attention would have to be paid to
pasture growth rate along with pasture cover and pasture quality.
Aiming at 1500kg DM/ha means that pasture quality can easily be lost, said the
FITT project report.
Ways of ensuring that pasture quality is maintained include:
Aiming for covers of 1200-1400kg DM, to keep leafy green pasture and therefore
preventing seeding and loss of quality,
Boosting pasture growth rates through the lactation period to ensure pasture is
responding, with at least two applications of 50kg N/ha, and
Lambing slightly earlier in the season, say in August rather than September, so that
longer periods of quality feed are possible while plants are in their natural vegetative
growth phase.
At the late November field day for the wise use of nitrogen project, David
reflected on the contrasts between 2005 and 2004.
He said that the 2005 winter and spring were not antagonistic to lambing, but that
pasture growth rates were no better than the previous year.
During the wet October lambs did not grow and therefore the key indicator of
growth rate in the birth to docking phase was down by 90-100g/day.
From then it was a catch-up job, which was not going to produce 30kg lambs at
weaning, he said.
Realistically, lambs would be likely to reach liveweights of 22/23kgs in late
November and 25/26kg on December 10. So daily weight gains during the full lactation
were going to be down around 200-240g/day.
At the time of the field day (November 24), the Gunsons were looking to $1.70/kg
store lamb values in mid-December.
The Gunsons have quarter-Finn Romney ewes, two-thirds used to breed
replacements and one-third mated to Suffolk terminal sires.
They expect to move the mating date forward 10 days to March 20 with the
strategic use of nitrogen.
They aim to market all surplus lambs by the end of January, which is a month
earlier than in recent years.
Hogget mating started in 2001, with a mating date of May 1. The average weight has
been 41kg but in 2005 they were only 38.5kg.
In previous years they have scanned 146% and docked 99%, but in 2005 they scanned
116% (88% in lamb) and docked 75%.
The historical performance of the main flock has been 190% to 200% scanning
and 170% lambing. In 2005 the MA ewes scanned 195% and the two-tooths 179%, for a
docking outcome of 156% in both cases.
The Gunson cattle policy is based on Hereford Friesian-cross cows with the first
calvers mated to a Limousin bull and the older cows to Charolais. In the past three years
replacement heifers have not be kept, so that the cow numbers would reduce by attrition.
Heifers are sold local trade at 195kg and the beef bull calves kept entire and
targeted to the store market at 450-500kg LW. As the stocking rate with bulls has
increased more have been sold store at 300-400kg LW.
On the intensive beef systems bulls were wintered at stocking rates of 2-2.5 per
hectare with good liveweight gains of 0.8-1.0kg/head/day. However the cattle were not
able to control the feed in October and November.
More intensive systems were initiated with higher stocking rates, lower winter
weight gains, better control of spring feed and consequently better production and profit
per hectare.
Now in their sixth year, the intensive bull blocks are stocked with 750-960kg
LW/ha starting in June and July. That is an average of 4.5 bulls, at average weights of
185kg. There were seven systems this past winter with 51-60 bulls per system.
They generally remain on their systems until December when most are sold store,
having gained about 707kg on average and up to 778kg LW/ha (net).
At the time of the field day the projections were for average per head weights
around 340 in mid December and 365kg if they were kept until mid-January.
However the rates of gain in that last summer month will fall to 0.75kg/head/day,
having been up at 1kg prior to that.
The objective is to get net beef production off the intensive beef system up to
1000kg/ha from May to December.
During the past two seasons David has moved the cow mating date back by four
to six weeks, to around December 20, which means more grass can be allocated to other
stock classes in the critical August/September period.
For example, last yeat the saved grass area per cow during calving was reduced
from 0.45-0.5ha (to be break fed) by 0.15-0.2ha to 0.3ha.
That meant that about 20ha of grass (for a cow herd of 100) could be reallocated.
Calving cows later also helps with the unpredictable spring growth.
This year no specific saved feed area was kept for the cows. Instead the cows
were set-stocked at one to the hectare with the lambing ewes to help maintain pasture
quality. David said this worked really well.
“There is less and less need for cows on this farm, however I will concede they
perform a very useful pasture control role and with October calving their feed demand is
minimised when feed is most valuable,” said David.
STORY TWO
Caption: Demonstrating sustainable farming practices will reinforce the view many
consumers have of New Zealand farm produce says farm consultant Bob Thomson, who
shared much of the speaking duties at last month’s field day with Northland host farmer
David Gunson.
By Hugh Stringleman
Regional councils will introduce regulations within five years to govern nitrogen
applications on hill country, AgResearch scientist Greg Lambert believes.
The regulations will be introduced to stop further degradation of upland streams
and rivers.
“What farmers are doing now on their farms is everyone’s business,” he told a
wise use of nitrogen annual field day on David and Erin Gunson’s sheep and beef hill
country farm at Waikeikei, Northland.
“The community has views on how farming impacts the landscape,” he warned.
“Farmers are getting less traction than the environment groups.”
The arguments will be all about environment versus profit.
“There is no argument in the long term, because without sustainable agriculture
there will be no profits.
“The conflicts occur mainly in the short term,” Lambert said.
More than one million tonnes of nitrogen are fixed every year by clover in New
Zealand, and 350,000 tonnes of nitrogen is applied with fertilisers.
“One quarter of our nitrogen is now coming from fertiliser, but comparatively
little of it is spread on hill country sheep and beef farms,” Lambert said.
Work at Ballantrae hill country research station has shown that using nitrogen on
hill country could be very profitable.
In Northland farmers could obtain responses right through the winter, although
that was also the period of greatest leaching.
The wise use of nitrogen fertiliser on hill country nationwide project, supported
by the Sustainable Farming Fund, Fertiliser Manufacturers Research Association and
Ravensdown and Ballance, seeks to find answers to the practical questions of how much
nitrogen fertiliser to use and how frequently to apply it.
The strategic use of nitrogen fertiliser to grow more grass in winter and spring
makes farming more flexible, not less, Lambert said.
Farmers have more options, particularly if they use a budgeting and management
tool like Overseer or Farmax, which require monitoring.
“We have to accept as ‘our problem’ the balancing of the environmental and
economic impacts of nitrogen use,” Lambert said.
Otherwise the terms of use will be dictated to farming.
Right now everyone is looking for voluntary compliance rather than regulation,
including the Northland Regional Council.
Kate Banbury, land management officer, suggested comprehensive farm mapping
as part of a land and environment plan.
“It will help convert environment threats into opportunities,” she said.
Farm owners should identify the limitations to land uses, including management
right down to paddock scale.
“This will enhance the sale value of the property through demonstrated
sustainability and attractive landscapes,” she said.
Farm consultant Bob Thomson said the world marketplaces already perceived
New Zealand as farming sustainably. But this needed demonstrating, in reality not just
perception.