Grass Fed Marbled Angus Beef at Mt Linton

High quality marbled beef can be produced efficiently off grass and winter crops with Angus genetics selected for intramuscular fat (IMF) and the beef will earn a worthwhile premium, according to Ceri Lewis, General Manager of Mount Linton Station. Marbled beef is usually produced with grain finishing of the premium cattle in feedlots, not from grass-fed cattle. Marbled beef is consistently rated higher eating quality than non-marbled and is highly valued in almost all premium beef markets around the world.

Mount Linton Station covers over 13,000ha in Western Southland and is owned by the McGregor and Masfen families. The McGregors have farmed Mount Linton since the early 1900’s and the Masfens became 50% shareholders in 2003. It has a huge carrying capacity of sheep and cattle on more than 12,000ha of pasture. Mount Linton uses size, entrepreneurship and determination to be a leader in genetics, with recording of Angus going back to 1991 and with Texel and Sufftex sheep since 1995.

The station’s total cattle numbers are 6500 head wintered, including 2600 mixed age cows and first-calving heifers, 1200 each of 18-month steers and heifers and 2500 calves (numbers of younger cattle come and go during the year). Mount Linton also has an Angus stud with 800 registered cows, selling more than 100 yearling bulls by private treaty from November onwards every year.

In late 2009, Mount Linton Station was approached by Dr Jason Archer, an AgResearch senior scientist based in Invermay, to participate in trials on producing lightly marbled beef from grass-fed cattle, using energy-dense finishing for the right cattle genotypes. The trial emphasised the natural, environmental and animal-welfare friendly approach of NZ pasture-based beef cattle farming, versus the grain-fed feedlot approach to finishing cattle elsewhere in the world. The trial measured the marbling potential of heifers.

Mount Linton had been using mainly Australian Angus sires that had high estimated breeding values (EBVs) for intramuscular fat (IMF), such as Booroomooka Theo T30, Merrick Rivers T149 and Te Mania Ambassador. More recently Rennylea C511 has also been used extensively. Lewis was confident that the propensity to marbling was present in the Mount Linton herd and a large ultra-sound scanning of 400 stud 15-month Angus heifers confirmed the high IMF presence. The heifers were also capable of very high growth rates on pasture of nearly 2kg LW per day in late spring and early summer, compared with the expected average of 1.2-1.6kg/day LW.

In addition to the main focus on cattle selection for soundness, fertility, mothering ability, low birth weights, calving ease, high growth rates, and moderate mature cow weights, Mount Linton is now selecting high IMF scores. Scanning results in recent years have shown that Mount Linton cows have an average of 7.2% IMF compared with the Breedplan average of 3.5%.

While the cattle genetically may have high IMF EBVs and high IMF scanning results, they still need the right feeding and finishing on a rising plane of nutrition to express that genetic propensity in marbling in the beef.

Mount Linton entered Angus heifers in the Steak of Origin Competition in 2012 and 2013 that objectively demonstrated the progress it has made with high IMF. The first year two heifers had marbling scores of 4 and 5, which Lewis commented, ”is as good as it gets off grass at that age”. The following year two Mount Linton heifers scored 6, while the best of the remaining British breed entries scored 4 and the majority were in the 1 to 3 range.

There are two visual assessment scales of marbling in beef, the Australian scale MSA of 1 to 9 and the Japanese scale of 1 to 14. The 6’s scored by Mount Linton heifers fed on grass was the highest score for the Steak of Origin competition.

This year Mount Linton ultrasound scanned all finishing cattle to correlate their IMF readings to the marbling scores from the carcasses when slaughtered. That will provide a powerful feedback for informing breeding decisions. The station has also planted 20ha of fodder beet, which will be used for winter-feeding of high-IMF cattle to enhance their marbling results. “Marbling can be very fickle, being the first fat to disappear when feed is restricted,” Lewis said.

Convinced that there is a worthwhile premium available in the markets for grass-fed marbled beef, in March Mount Linton sent 40 heifers to Greenlea Meats in Hamilton for processing for Firstlight Foods, a premium meat company. “This product needs to be marketed into a niche, where the birth-to-market story is told,” Lewis said. Firstlight undertook marbling score and taste testing and sent the premium product to high-end customers in the United States, like hotels and restaurants but the feedback has not been received yet. Lewis had earlier advised Firstlight principal Gerard Hickey of the marbling scores being achieved off Mount Linton Angus grass-fed cattle. Firstlight already has a big Wagyu and Wagyu-cross beef programme aimed at producing grass-fed marbled beef for sale.

“Grain-fed beef is traded solely on its marble score; the higher the score the higher the price. But the health benefits of grass-fed over grain-fed are also being recognised and fuelling demand for grass-fed marbled beef. We have been taking a great interest in the premiums that are being offered and are involved in trial work with several of the processors trying to further develop this market. The profitability of a beef cow herd and hill country farm would change significantly if it received $6/kg for a finished Angus steer or heifer with the right genetics,” Lewis said.

Mount Linton has artificially inseminated as many cows as it could to the highest marbling bull in the Angus breed and its own-bred yearling bulls used as follow-ups were all in the top 10% of the breed for IMF. “While we have a strong focus on carcass quality, we are very mindful that the maternal traits are the number one driver of profitability and we are not compromising these,” he said.