Carcass data helps produce high-quality grass-fed beef

Having a strong focus on carcass data is helping Mount Linton Station to produce high-quality, grass fed beef in challenging climatic conditions.

The 13,200ha station, located at the foothills of the Takitimu Mountains in Southland, produces 2,400 Angus heifers and steers each year. They also run 750 pedigree Angus cows, selling 300 breeding bulls privately.

All beef is finished by 18 months off forage alone and is sold to Silver Fern Farm’s quality beef scheme, where the meat is graded using an eating quality (EQ) system.

Cows in New Zealand

Last year, their hit rate for EQ was 85% – almost triple the national average of 28% – which is earning them a premium of NZ$150 (£64) an animal. This is having a big effect on their bottom line.    

See also: Scanning eye muscle helps cut beef feed costs                                                                                                

General manager Ceri Lewis, who hails from Wales, believes their success is down to the fact they have been heavily recording carcass data.

“We really started pushing carcass data in the past  seven to eight years,” says Mr Lewis. This was led by a drive to produce premium beef.

Breeding selection

A big emphasis has been placed on breeding from animals with superior carcass EBVs.

The Silver Fern Farms Eating Quality (EQ) grading process guarantees tenderness, juiciness and tastiness by measuring meat marbling, pH and colour.

Pedigree cows are synchronised and AI’d to high-genetic merit Australian Angus sires in December. In addition to the main selection criteria for maternal traits, AI bulls must be within the top 1% for carcass traits, with positive rib and rump fat and exceptionally high intramuscular fat (IMF) and marbling scores.

“Our biggest push and our point of difference is we have a really strong focus on intramuscular fat and marbling.

“They also have to be 100% for temperament and structurally sound so I go over to Australia every year to look at bulls,” explains Mr Lewis.

Currently, the station owns a half share in the breed’s highest-marbling sire, Rennylea H840, which boasts an EBV for IMF of six, compared to the breed average of 1.5. He is going to be used extensively in the herd’s AI programme this year.

General manager Ceri Lewis.

General manager Ceri Lewis.

“We used him lightly last year and have about 70 calves on the ground by him this spring, but we will use him heavily in next month’s AI programme,” says Mr Lewis.

See also: Embryo transfer speeds up genetic gain

They are also taking advantage of genomics to give them a more accurate picture of which bulls to use. Each year the best 50 yearling bulls are selected from the pedigree stud for genomic testing based on their EBVs and 30 of these are kept for use as sweeper bulls within the stud at a ratio of 1:15.

“If they return they all come on heat on the same day, so you have to use a lot of bull power.”

Generally, 70% of the cows hold to AI within the first cycle before getting a second chance at being served naturally within the second cycle, which keeps the calving period down to six weeks, adds Mr Lewis.

Meanwhile the commercial cows are mated naturally to home-bred, proven sires within the top 1% for marbling and maternal traits at a ratio of one bull to every 50 cows for six weeks to maximise genetic gain.

Farm facts

  • Owned by the McGregor and Masfen families, who are 50/50 shareholders
  • Mount Linton is one of the largest privately owned stations in New Zealand
  • 13,200ha in total, growing 80ha of fodder beet for winter feeding
  • Land ranges from 250-900m above sea level
  • 750 pedigree Angus cows, all performance recorded
  • 2,400 commercial Angus cows
  • 45,000 breeding ewes that are Texel Romneys alongside a Suftex terminal and Texel Romney maternal-recorded flocks
  • Prime beef is sold through Silver Fern Farms as part of eating quality-assured scheme for about $1,800 (£770)
  • Cost of production is $1,080 (£465) a head
  • The station spends $1m/year (£430,000) on a land development programme, turning 300ha of hill country into productive land
  • 150 pedigree bulls are sold as yearlings and another 150 are sold at 18 months after being used in the stud. Bulls sell for between $2,750-$5,000 (£1,180-£2,150) depending on their EBV figures.

Sire parentage of commercials calves is unknown, although Mr Lewis says they have a reasonable idea of how these bulls will perform because they have already been used in the stud programme.

However, next year Mount Linton will be DNA-testing calves from the commercial herd to identify sires. The test, which costs $60 (£25) a head, is being funded by a New Zealand Beef and Lamb project. This will provide powerful feedback to inform future breeding decisions, says Mr Lewis.

Stud cows are brought to the downs at calving on 15 September to make recording easier, but the commercial cows remain on the hill, where they are expected to calve unaided when calving begins on 5 October.


Ultrasound scanning has played a huge part in unearthing outliers in the genetic programme.

As well as weights being recorded at birth, weaning, 400 days and 600 days, bulls are ultrasound scanned at 11 months and heifers are scanned at 14 months to measure rib, rump fat, eye muscle area and intramuscular fat.

In recent years, growth rates at 600 days have increased by 15% – 30kg – and scanning results show Mount Linton cows have an average of 7.2% IMF compared with the Breedplan average of 3.5%.

This is helping them to achieve exceptional marbling scores off grass, with average grades hitting up to 8 on a scale of 1-9, which is unheard of outside the Wagyu breed, says Mr Lewis.

“The biggest reason cattle don’t meet the [EQ] grade is because they aren’t marbled well enough. That’s not a problem for us. We can pretty much guarantee we will get a minimum marbling score of two.

“The biggest benefit of scanning is it identifies the outliers – animals that are likely to perform well outside their mid parent breeding values [H840 was one of these]. The use of these animals in an AI breeding programme can turbo-boost genetic progress in the traits you are looking for,” adds Mr Lewis

“Essentially they are freaks, but they have the potential to be herd changers – even breed changers.

“We scan bulls at 11 months because we are selling a number of them as yearlings and our buyers want the carcass information on the bulls. It is not ideal timing, because they are coming out of the winter and often do not have high levels of fat cover, but it does identify the outliers better.”

See also: Scanning terminal sires is key to profitable sheep production

Meanwhile, heifers are scanned at 14 months because that is the ideal time in terms of their fat covers, he adds. “We also scan the commercial heifers as a culling tool and sell the bottom 10%.”

Pedigree cattle and calf

Ideally fat covers need to be 2-6mm at 11 months and 6-12mm at 14 months, with moderate mature weights of 560kg, says Mr Lewis. He believes this is critical to ensure females can withstand being wintered on the hill and tussock country up to 1,000m above sea level, which is prone to heavy snowfall.

“The reason good fat covers are important to us is during the winter at Mount Linton the cattle lose up to 200kg [about one body condition score point] due to the climate. The fatter they are, the more they are able to metabolise the fat and use it for energy to keep warm and feed their calves. They also bounce back very quickly in the spring and start laying down fat again for the next winter.”

Mr Lewis says there is also a strong genetic correlation between positive rib fat and fertility in heifers, which helps to identify highly fertile breeders.

This scrupulous eye on production has seen calving percentage rise to 92% on average among heifers and 97% in mature cows across both herds.


It is not just genetics, concedes Mr Lewis. He believes animals still require the right nutrition to express that genetic predisposition to marbling in the beef.

After spending their first summer on grass, fatstock is outwintered on fodder beet, which Mr Lewis believes enhances their marbling quality because of its high sugar content.

“The fodder beet has really been the catalyst to get them gone by the end of the winter because they are not taking a check in growth over the winter. In fact, they are averaging 1.5kg/day.

“Only 10% of cattle in New Zealand are killed at 18 months because they haven’t got the growth rates and management system in place. The cost of taking an animal through a second winter is $500 [£213].”

Pedigree beef animal

Mr Lewis says being disciplined when it comes to hitting targets ensures cattle are gone quickly too. Last year, steers averaged 285kg deadweight and heifers averaged 265kg deadweight, with meat yields at 56%.

“We know exactly where they need to be and when. They are weighed at weaning and monthly from September onwards.”

By the time they are strip-grazed on fodder beet, they are split into three weight groups so weights can be monitored weekly.


Mr Lewis has some big plans for the future. Recent interest from a UK company that would like to buy 20 carcasses a week, and terrific growth in US grass-fed beef sales, have sparked a bright idea.

“I would like to develop our own grass-fed beef brand. Mount Linton genetics are reasonably well established. We are probably already supplying about 5,000 calves to the industry every year through farms that buy our bulls.

“If we could buy those calves back and buy a second farm and finish them ourselves it would give us some leverage to launch our own brand.”