Middlehurst High Country Station

July 2009

Producing fine micron merino wool on a high country station

Middlehurst is a high country station of climatic extremes. Frosts are frequent and can occur at any time, temperatures sometimes exceed 40 degrees celsius the mountainous back-country is snow-capped through winter. Complementing Middlehurst are properties at Cheviot in Canterbury and Havelock in Marlborough, which extend a tight window of pasture growth and increase options for marketing stock.

Willie and Sue Macdonald purchased Middlehurst in 1998. At the time, the 16,723 hectare (10,723 hectares effective) station was fenced into 11 blocks plus holding paddocks. Overgrazing by stock and rabbits had caused areas to erode then be invaded by the flatweed Hieracium.

They bought the property for its naturally fertile soils, scope and good balance of north and south facing country, and the quality of the merino sheep run there; large-framed with a good constitution and plenty of wool.

The last 10 years have seen intensive improvement of the land now in 19 blocks plus paddocks - and livestock. To add flexibility, in 2001, a 550 hectare finishing block at Cheviot in North Canterbury was purchased and in 2008 150 hectares at Havelock, at the head of Pelorus Sound.

Altitude at Middlehurst ranges from 600 metres above sea level near the homestead to 2400 metres, on the western flanks of the rugged Inland Kaikoura Range. Just over two thirds of the property is Crown leasehold and 5303 hectares is freehold.

Temperatures fluctuate from -10degrees celsius to over 40 degrees and rainfall from 360 and 1030mm, with a long term average of 550mm. An average of 200 frosts a year and snow can occur at any time.

The pasture growth window is extremely narrow, from late October/mid November through until mid January.

Middlehurst winters 4500 merino ewes (including two tooths), 4000 mixed sex hoggets, 200 steer calves and 500 Angus cows mated with a composite bull.

Before ramping up production at Middlehurst, the Macdonalds took the pressure off the most sensitive country, selling the 1800 head merino wether flock so land that had been grazed hard for years could be spelled.

Around 30 kilometres of fencing has broken blocks which had ranged from 660 to 1500 hectares, down to 200-400 hectares.

Taking advantage of frost lift, areas infested Hieracium were oversown in mid to late August with Tahora white clover, Leura sub clover and Tekapo cocksfloot with a little Montgomery red clover added. The seed was flown on with 100kg of sulphur super 30 (30% sulphur).

Caucasian clover, renowned for its ability to withstand drought, was sown on more arid sites with lots of Hieracium.

Developed blocks were closed up from spring through to summer for two years, to encourage reseeding.

The fertiliser programme has now reached a maintenance phase of 100kg/ha of Maxi Sulphur Super (47% sulphur) applied over 6000ha, with 2000 hectares treated each year.

Applications were ratcheted back last year, due to an exponential increase in prices per tonne. Willies worried that gains made could be lost, if applying fertiliser becomes uneconomic. We are concerned that without fertiliser, particularly sulphur, improved pastures wont take long to revert to Hieracium.

The price has since dropped, but not to a level where fertiliser would be flown on without question.

On the home block, the Macdonalds have established 21 hectares of lucerne and 12 hectares of winter crop destined for sowing in lucerne. The lucerne is each year baled into hay used as winter feed reserves, and directly grazed by ram hoggets from January until May.

As well as increasing finishing and marketing options, investment in the Cheviot and Havelock blocks has reduced their exposure to climatic and financial risk, says Willie.

Theres lots of fine-tuning of numbers between the three properties, to suit the season.

Generally, the Cheviot farm carries 700 cast for age ewes mated to a poll dorset ram, 800 merino hoggets carried through until the following year, 200 heifer calves, 150 rising two-year-old (R2) heifers and 120 R2 steers.

Pasture growth at Cheviot peaks from August and tails off in around mid November, just as it starts to take off at Middlehurst. The productive season at Havelock which has a reliable 1500-2200mm rainfall extends from September/October through to May, with a reliable 1500-2200mm rainfall.

In late September, around 3000 surplus hoggets are shifted to Cheviot on time to catch the pasture production curve, and finished here to meet a winter lamb contract by November. Cast for age ewes are also sent south where they are mated with a Poll Dorset ram. Depending on the season, they are either be sold with lambs at foot or kept on for another year to raise another lamb or two before being culled.

Not only has finishing hoggets and running cull ewes off-farm improved profits, it enables priority to be placed on ewes that will breed replacements at Middlehurst. Lambs are then raised on the high country at little cost.

Cattle only are run at Havelock, where 1500-2200mm of rain falls a year. Around 120 R2 and 50 R3 steers are finished here each year. After weaning, 200 heifer calves leave Middlehurst for Cheviot. Half go to a bull as yearlings and half are killed at local abattoir, Harris Meats. Seventy five in-calf R2 heifers return to the high country and the truck is back-loaded with that years crop of calves. The remaining 25 are killed.

The Middlehurst environment is extremely fragile, so the Macdonalds emphasise protection of their land ahead of maximising production.

The months from mid January until mid November are generally extremely dry. For this reason, pasture is saved through the productive summer months to carry stock through winter.

Keeping cover on soils is critical. Rabbits are a major threat to soil stability, and while rabbit calicivirus disease (RCD) knocked back numbers soon after their purchase of Middlehurst, resistance has since built up and populations are getting away.

To protect their fragile country, aerial poisoning has been carried out over the last two winters and a part-time rabbiter employed.

Briar is one of the main weeds at Middlehurst, but it is a blessing as well as a curse providing shelter for stock and nutritious berries during the tough winter months.

The Macdonalds have learned to become snow-wise. Ewes are run on the back country during winter so warmer blocks can be utilised at times when high productivity is needed, such as leading up to tupping. They are mustered back in early September usually in better condition than they left - for shearing then.

Snowfalls seem to be getting increasingly erratic, says Sue. In July last year, an unusually wet and heavy dump fell for two weeks, covering a third of the farm. Snow raking the sheep out by stomping paths in the snow was not possible, so mobs were located in the Macdonalds aeroplane then baleage was dropped in by helicopter.

The Macdonalds purchase of Middlehurst included all the stock. While the merinos were robust with plenty of wool, this was not sufficiently fine to meet lucrative contracts with New Zealand-based outdoor garment manufacturer, Icebreaker.

Using semen and live rams purchased from Wallaloo Park Merino Stud in Victoria, Australia, the Macdonalds have developed dual purpose merino ewes that cut 6.5-6.8kg/head of 19 micron wool (17.5 microns for hoggets); a considerable improvement on the 5.4kg/head of 23 micron wool produced at takeover.

AI was an intensive operation, requiring four workers plus a technician for the 18 days ewes were kept in the yards with teaser rams then mated as they became fertile. Regular feeding and weighing ensured weights were on a level plane pre, during and post AI.

Ewes are now flock-mated, apart from an unregistered stud flock of 250 ewes which are laparoscopically inseminated each year. Middlehurst rams are now sold both in New Zealand and overseas, adding another strand to the business.

The payback on improved genetics has been attracting a contract with luxury outdoor garment manufacturer, Icebreaker, for 80% of the clip and also with American sock manufacturer, SmartWool. The contracts are facilitated by the NZ Merino Company.

There is a strong emphasis on meat as well as wool production. Since the purchase of the Cheviot property, cull hoggets have been finished to an average 20 kilogram carcase weight. Most are killed in November, on time to catch early market premiums.

The Macdonald children attend a correspondence school unit on the property, which currently has seven pupils on its roll. Correspondence lessons are supervised by trained teacher and neighbour, Carey-Anne Hamilton.