Deep dive on carcase traits and calving ease at Beef Week

Herefords Australia took a deep dive with two seedstock producers on their philosophy around what they believe the breed needs to be aspirational about – carcase traits and calving ease.

Wirruna Poll Herefords, Holbrook, and Yavenvale Poll Herefords, Adelong, opened their gates to visitors during the 2022 Southern Beef Week, with their bull sale teams on display, and outlined their focus on performance recording and objective measurement to achieve above breed average genetic gain.

Both herds have had a strong focus on selection for marbling over the past decades and run large contemporary groups – Wirruna joins 800 registered females while Yavenvale has 900 registered and 150 commercial females to calve in 2022.

Wirruna has subcategories for bulls including growth, muscle, specialist heifer and good herd bulls.

“For example, the job description for the growth bulls is they must be in the top 20 per cent of the breed or better for growth traits,” Wirruna co-principal Ian Locke said.

“On average, a higher growth bull will have a higher birthweight and mature cow weight, but we look to break the usual correlations by measuring and selecting outlier animals that can bend the growth curve.

“Our job as seedstock producers is to measure all these things so we can identify animals which are born easily, grow well at the 200- and 400-day weights but then don’t keep growing until we have extreme animals that look and eat like a draught horse.”

The Locke family early wean their calves at an average of four and-a-half months (bulls at 200kg and heifers 190kg), allowing a greater number of cows run at a higher stocking rate.

The average birthdate is August 25 and weaning is from the first week of January, with all calves yard weaned for 10-14 days and bunk trained on a pellet ration comprising 12.5 per cent energy and 17 per cent protein plus good quality ad lib lucerne or canola hay.

“With early weaning, the cow turns dry and goes onto the low value pasture while the calves go onto the highest value pasture of ryegrass, lucerne or early oats,” Ian said.

“It’s about running cows under commercial stress conditions at high stocking rates, 17DSE/ha compared to the district average of 10-11DSE/ha (average rainfall is 750mm).”

During dry years the Wirruna steers are sent to feedlots but in good seasonal conditions they are caried through to heavier weights and sold over the hooks to obtain the valuable MSA carcase data.

In the past, the family has value added a portion of their grass finished steers through Provenir to produce Wirruna branded beef with some cuts reaching a marble score six.

Ian said the Provenir pathway gave additional valuable feedback on eating quality, cutability, tenderness and flavour.

“Years ago, especially when we kill surplus heifers, the MSA kill data for marbling used to be zeros, ones or the occasional two, but now it is more ones, twos and the occasional three.

“Everything in cattle breeding takes time but it is changing, and we all recognise Wagyu play a part in the marbling market however we see that high end as a niche market, and we are not trying to be there.

“We want to be relevant to the Australian beef industry where they want a little bit more marbling of two and three score, recognised for adding juiciness and a satisfying beef meal experience.

“It doesn’t have to be extreme, but we want to be able to compete against the other breeds for high quality beef.

“We are recognising we have variation within our breed and there are cattle which do or don’t marble, and if you choose to drive the trait, you can select animals that will marble equally as well at the high end.

“When we are in the game of breeding cattle, we have to take a visionary approach and recognise MLA has done a lot of eating quality research to show the consumer likes a level of marbling, and we have to be relevant in the Australia beef industry by providing that product.”

At Yavenvale, cattle consigned to the Teys Grasslands brand enable the Pearce family to benchmark individual animal and sire line performance.

In 2017, Yavenvale was named in the top 100 NSW producers for the MSA Excellence in Eating Quality Awards.

“It’s the real world aligning with scientific data – we are seeing the bulls which sire those steers and cull females grading well on the MSA Index have good IMF EBVs on BREEDPLAN,” Yavenvale co-principal James Pearce said.

“The benchmarking is important as it allows us to show our clients the genetic selection is working through the supply chain.”

Yavenvale has more than 400 active females ranking in the top five per cent of the breed for intramuscular fat.

“When we were ultrasound scanning heifers in 2000, there were a number which would register as the bare minimum or maximum on the scanning machine,” James said.

“The average of 20 years ago has now doubled in that time.

“Marbling can be fast tracked by buying bulls in the top one to five per cent but it is critical not to single trait select.

“The term ‘marbling is a free trait’ was coined and I think it is a valid one. You do get more subcutaneous fat with intramuscular fat but that doing ability is extremely important, especially for fertility.

“Our breed is terrific for fertility – there is a genetic correlation between positive rump fat and female fertility.”

Ian Locke has found no negative correlations when selecting for marbling.

“We all want growth in cattle but we don’t want the hangovers of heavy birthweights or large mature cow size,” he said.

“Marbling is most correlated to fat – positive fat allows us to run a lower cost cow herd which is fertile as it is able to put on the fat when the grass is there and live off it when it is not.

“There is a slight negative correlation to muscle but through selection of outliers, we have been able to drive the muscle trait as fast as the marbling trait.”

Wirruna started ultrasound scanning for intramuscular fat under the Validation Project in 1998 to determine the importance of marbling

“By 2002, Herefords had an estimated breeding value for marbling and we knew we could drive it,” Ian said.

“Every year we made incremental gains genetically but over time it compounds.”

Today, Wirruna sits in the top five per cent of the Hereford breed for marbling and is continuing to drive that trait.

“We have been driving muscle at the same time, our fat is going up but there will be a ceiling as we don’t want to keep driving fat and lose yield,” Ian said. “So, we need muscle too to keep acceptable meat yield.”

James Pearce believes breeders need to focus on calving ease and moderating birthweights whilst achieving reasonable growth.

He said inquiry for heifer bulls was exceptionally strong due to herd rebuilding.

James recommended having heifers grown out to a critical mating weight pre-joining.

Producers should ensure heifers are on a continuous plane of nutrition post-joining and managed correctly during the last 90 days of pregnancy to prevent calving difficulties.

“That should be achievable on grass only under commercial stocking rate conditions for the heifer to calve as a two-year-old,” James said.

“Select a bull with the correct shoulder structure and length of neck, plus EBVs for calving ease.”

With bull prices skyrocketing, James has observed trends of commercial producers wanting dual purpose bulls for heifers and cows, or using bulls over a split joining with a desire for longevity to reduce the per calf cost for their enterprise.

Ian Locke said the Hereford breed had switched onto lowering average birthweights.

“I keep a foot on birthweight at around +3.0kg and push growth from that stage,” he said.

“Originally, we had Birthweight EBVs and not Calving Ease EBVs. People used Birthweight as a proxy for selecting easy calving animals. If we want to select for ease of calving, to me the important trait is calving ease and not birthweight.

“I encourage commercial clients to look at Calving Ease Direct EBV and don’t get too wrapped up in birthweight.

“I aim to keep our birthweights stable while trying to lift growth without getting into a growth race.”

Breeders need to be careful not to drive the mature cow weights to be ever larger. In some British breeds cow size has blown out and Ian said there were no benefits in extreme high maintenance females.

“Certainly, coming out of the drought years, commercial producers are aware of the pitfalls of large framed cattle.

“The ideal heifer bulls provide lower birthweight and good calving ease (as do their sire and dam) and come out of program where there is a consistent breeding program for those traits.

“You want those heifer bulls with neck extension and tapered shape through the shoulder.”

The Lockes have an average critical mating weight of 350kg and join heifers at 14 months of age over six weeks.

Any heifers failing to conceive over two cycles are no longer in the breeding herd.

“Every female must have a live unassisted calf they take through to weaning, resulting from a six-week joining so an eight-year-old cow has jumped many hurdles by calving every 365 days under the pressure of a high stocking rate,” Ian said.

“Running these key disciplines under heavy stocking rates screens out individual females I don’t want to replicate and leaves us with a very maternally efficient cow herd.”