Mark Ivey with the Glentanner stud ram hoggets, on the rolling downs at the southern end of Lake Pukaki.

Several hundred hectares of cultivated rolling downs nestled at the southern end of Lake Pukaki is home to the Glentanner Station merino stud.

The Ivey family, who bought Glentanner in the 1950s, has been developing the stud since 1987. It is the passion and hobby of Ross Ivey and son Mark is also heavily involved.

These days the stud runs to over 600 ewes, sells 60 to 70 rams a year and has a reputation for producing commercial sheep with footrot resistance that do well on the wet gorge country typical of the station, lying as it does close to the main divide.

Pat Deavoll Glentanner ram hoggets: the Iveys like their rams to have a visually “open” head and good conformation

The rolling downs, which are separate from the rest of Glentanner, became part of the station in 1984 as compensation for land lost with the raising of Lake Pukaki. Stock no longer have access to the lake due to a covenant put on all land facing the lake, so Meridian has put a reticulated water scheme on the property.

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The paddocks are highly modified and make for prime pasture for the merino stud.

The stud has grown significantly the past couple of years, Mark says. In 2014 the Iveys bought the Glenthorne Stud off Bob Brown, who owned Blue Mountain and a smaller farm on the south bank of the Rakaia called The Glen. This year the Iveys will sell between 80 and 100 rams, most off-farm

"Bob didn't have time for the stud and wanted to see someone carry it on. We bought 200 ewes and 60 ram hoggets off him and took on some of his clients," Mark says.

"There is a lot of work these days in stud sheep. The commercial clients want more out of the merino than in the past. Back then the merino was seen as just a wool sheep but now with wool not being so valuable a lot more people are interested in a dual purpose sheep. There is a lot more work and cost for us in breeding them."

These days the Iveys eye-muscle scan their merino hoggets and foot-score the stud for footrot. The foot-score is done at Lincoln University and the station has been doing this for 15-odd years. Merinos have a softer white foot that is susceptible to foot-rot, Mark says.

"The old test has been around for 17 years - we and Bob Brown were the first to use it, hence his good foot-scores were part of the reason for us buying his stud. It is also one of the selling points for our rams - we sell a lot to wet gorge properties that are susceptible to footrot. A blood test delivers two scores anywhere between one and five. The ram will have inherited one score from his mother and the other from his sire."

BIG NOT ALWAYS BEST

Merino New Zealand (NZM) has used government funding to refine the test and come up with more accurate readings, and this has been good, says Mark, but not perfect if used on a large scale.

If rams with good foot scores are used on commercial sheep for 10 years, on average susceptibility to foot rot will reduce and the Iveys have determined this in their commercial flock.

"Obviously, this test should be better because the technology of the old one is 20 years old now. Foot-score testing is an important selling point for our merinos. Most of our clients are interested in the scores."

Eye-muscle scanning and ultra-sounding for fat depth in the kidney area is also important and is done by a private contractor. More specifically the Iveys are looking for the ratio of eye-muscle to live weight. This indicates yield and allows them to rank the rams - based on them all being fed the same - within the mob to determine which are better yielding.

"Just because an animal is big doesn't necessarily mean it's the best," Mark says. "The eye muscle area could be fairly small. Determining the meat yield is also beneficial to lamb survival and the general thrift of the ewe flock is better if they have some fat on them and a larger eye muscle area relative to body weight."

He says this usually correlates to other beneficial traits in the animal like footrot resistance, which is determined by the sheep's immune system. A sheep that's fat and healthy won't get footrot, and is usually more resistant to parasites. Big fat sheep seem to tolerate a higher parasite egg count.

The Iveys use estimated breeding values (EBVs) but Mark says they would never get to the extreme of using EBVs alone. They employ an expert sheep-classer to make a visual assessment which is combined with the EBV.

EBVs are also used to collate statistics for wool. Mark says they produce a medium to strong micron wool with the commercial ewes and wethers averaging 19 microns.

"That's where we want to be," he says.

"We are trying to breed rams 18-20 microns, in the dual purpose range of strong micron wool. We also breed a larger framed animal which is different from the Central Otago tradition of fine or ultra-fine micron sheep."

"This type of sheep suits Glentanner's gorge/ mountain country. Our rainfall averages from 50 inches at the homestead up to 120 inches where it borders on Aoraki Mount Cook National Park. It is very late country - the mountains act like a large radiator, cooling down the air. Down at Pukaki, where the stud is, it's two to three weeks earlier and the rainfall around 25 inches. The downs have a much warmer climate but it's unreliable as far as rainfall goes in the summer."

Glentanner's owners like their rams to have a visually "open" head (their sheep are known for this), and good conformation. The Iveys are particular about the animals having sound pasterns and hocks - this means the shoulders are square and there is no "table-top" between the shoulders to hold water.

"Probably more so than micron we are concerned with the staple structure of the wool," Mark says. "We look for a broad crimp that stands up and dries faster. Anything too flat, cross-fibred or dour won't dry quickly and will end up water damaged and discoloured."

Glentanner's wool is sold to NZM and goes to the likes of SmartWool, Icebreaker and Designer Textiles International. The station used to have more specific contracts, says Mark, but the last few years NZM has done the brokering and they just supply.

This year the Iveys will have four new clients garnered from the Bob Brown legacy. The clients will be buying Brown's rams because Glentanner bought 50 of his ram hoggets. Glentanner will supply Brown's existing clients through the transition year and the following year the clients will buy Brown's ram hoggets but they could be from a Glentanner ewe.

The Iveys use Chris Bowman, an Australian sheep classer to finalise what rams they keep for sale. Brown does a visual assessment of the young rams and Mark says his "eye" is worth paying for.

"We are the farmers and know a little bit but at the end of the day we only do this a few days a year, whereas Chris does it 365 and we would be foolish not to listen to him. He works with a lot of different studs, particularly the ones in Australia that show quite prominently."

"In a nutshell, our stud had to get bigger to make all the EBVs and info gathering worthwhile. And it's fair to say smaller studs selling only 20 or 30 rams are either chucking it or getting bigger these days. It's happening over the whole industry."