EATING quality research likening Tattykeel Australian White lamb as the Wagyu of the sheep world has highlighted the need for more purebred and crossbred-based meat tasting studies, according to James Cook University Associate Professor of animal nutrition and genetics Aduli Malau-Aduli.
Assoc. Prof. Malau-Aduli joined the JCU College of Public Health, Medical and Veterinary Sciences in Townsville last year and was approached by Tattykeel Australian White stud principal Graham Gilmore to do some independent meat analysis and taste testing.
Mr Gilmore, his brother Martin, and his sons James and Ross conducted all the development the Australian White as a self-replacing, haired, meat sheep from the Poll Dorset, Texel, White Dorper and Van Rooy breeds on their Tattykeel farms.
Mr Gilmore said he sought independent meat testing of the Australian White lamb after extensive positive feedback from consumers, butchers and chefs on the meat’s eating quality.
More Australian White flock analysis needed
Assoc. Prof. Malau-Aduli has done extensive research on the intramuscular fat content in the meat of various purebred and crossbred sheep, looking at fat melting points and long-chain omega-3 fatty acid content, and relating this to consumer taste-testing.
The JCU researcher’s preliminary work on Tattykeel-bred Australian White lamb loins has led him to liken the intramuscular fat content and fat melting point of the lamb to highly marbled Wagyu beef.
Wagyu cattle have a genetic predisposition that allows, under feedlot conditions, the production of highly valued fat-marbled beef with a higher percentage of unsaturated fat and omega-3 and omega-6 fatty acids than typical beef.
Significantly, the Tattykeel-bred Australian White lamb tested came from commercial pasture-fed animals, whereas most Wagyu meat is marketed from cattle fed a high-grain feedlot diet.
Intra-muscular fat and the melting point of fat are indicators of the content of desirable long-chain omega-3 polyunsaturated fatty acids and eating quality. Assoc. Prof. Malau-Aduli said the Tattykeel Australian White lamb he tested had a minimum melting point of 35.5 degrees, averaged 37 degrees and had a range of 35.5-41 degrees. Most other Australian sheep meat he has tested had fat melting points of 42-48 degrees Celsius.
After 27 years of research, he considered the Australian White meat to be the closest sheep meat equivalent of Wagyu beef, known for its exceptional IMF and eating quality. He has worked with Wagyu beef breeds in Japan for two years as a Japan Society for the Promotion of Science Research Fellow.
“Unless there is another (sheep) breed that I haven’t worked with, but based on the breeds I have worked with in my entire career, I haven’t seen any sheep meat with as high intra muscular fat content and with as low fat melting point as the Tattykeel Aussie Whites,” Assoc. Prof. Malau-Aduli.
To date, he has only analysed randomly selected lamb loins and shoulder muscles from Australian White flocks of Tattykeel commercial clients.
“That’s why I want to conduct a more comprehensive analysis with more samples across the F1s, F2s and the whole flock.”
He has also analysed the fatty acid content in raw and cooked lamb to see what might be lost during cooking.
“We have been able to demonstrate that using different cooking methods you don’t lose the fatty acid composition at all.”
Assess actual eating quality under various feeding regimes
Assoc. Prof. Malau-Aduli has also done some eating quality research on various sheep crossbreds in Tasmania, before moving to the JCU campus in Townsville. This work has been done on sheep under pasture and feedlot management conditions.
“We’ve worked with Corriedale-Merino crosses, White Suffolk-Corriedale crosses, Merino-White Suffolk crosses, Merino-Poll Dorset cross and Merino-Suffolk crosses and a whole range of other breeds and supplementary feeding regimes.”
Assoc. Prof. Malau-Aduli’s research has not been funded by Meat & Livestock Australia, the Sheep CRC or Australian Wool Innovation. He has not been involved in the Sheep CRC eating quality research aimed at determining meat trait estimated breeding values.
“One of the things that attracted me to Graham Gilmore (Tattykeel principal and Australian White breed founder) was his ability to challenge the so-called status quo.
“Over the years he has done a brilliant job of implementing a very very strict line breeding program after crossing, to get a really good blend of the Van Rooy, Texel, White Dorper and Poll Dorset breeds mixed in the right proportion.”
He is not against the use of estimated breeding values in sheep breeding.
“I have worked with EBVs,” he said.
“But I keep telling people that EBVs are estimated values.
“They don’t really explain to you every percentage of the variation that is based on population averages.
“For example, if a farmer decides to inflate the values that he has got and then submits that to the EBV computing body, they have no way of actually working out what is real and what is unreal,” he said.
“With computing, what comes out at the other end is based on what you put in.”
“Maybe it is time to reflect and take a step back and say well, maybe the EBVs have done a good job in terms of selection and breeding of animals, maybe it is time for us to now evaluate their actual eating quality.”
Assoc. Prof. Malau-Aduli believes the Australian sheep industry should be assessing the relative eating quality traits of its various breeds and crossbreds under different feeding regimens.
“At the end, what you want is to meet consumer demand and at the moment, people are interested in healthy meat, but they are also interested in something that is really tasty.
“The only way you can strike that balance is by trying to see if you’ve got the right mix, the right breed and the right feeding to bring out that delicate balance in eating quality,” he said.
“Over the years what people have emphasised is selection for large meat yield, large muscle, which is OK, but the downside to that is that the meat is lean and the taste can be compromised, completely lost or is not there as you want it due to very little IMF.
“So I think the industry should focus more on trying to evaluate the different breeds and what breeds fit what (pasture based or lot-feeding) system.”
He believed it was possible specific breeds had breed-specific meat eating quality traits which needed to be defined.
Need for breed eating quality comparison under one system
Assoc. Prof. Malau-Aduli has also studied meat from purebred Poll Dorsets, but not Southdowns or Texels. He recognised that most lamb produced in Australia is from crossbreds, but said the management system’s effect on eating quality also needed to be considered.
“The problem is if you take samples at random from different management systems.
“In all cases, we have got all these breeds and maintained them under the same management system, same feeding for the same duration and then killed them at the same end point to minimise all other significant environmental differences between them.
“So it goes beyond just analysing the different breeds in different systems; they have to come under the one management system to remove bias.”
Assoc. Prof. Malau-Aduli agrees with the Tattykeel approach to use selective line breeding to enhance positive traits without the use of EBVs and directly test meat for eating quality with consumers.
“That way you can then be able to come up with a unique DNA signature for each breed that is based directly on the performance of that animal, not on some estimated breeding value.”
Mr Gilmore said the next step is more extensive research and the release of more eating quality details on Australian Whites in September at the next annual Tattykeel ram sale.
According to James Cook University, Assoc. Prof. Malau-Aduli is internationally recognised as an academic leader, teacher and researcher with cutting-edge expertise in genetics-nutrition interactions in omega-3 fatty acids influencing sensory traits associated with meat and milk quality. He has attracted more than $3.7 million in collaborative projects in Australia, Asia and Africa; mainly from the Australian Centre for International Agricultural Research, the Australian Wool Education Trust, CSIRO and Dairy Australia.
Editor: As indicated in the above article, there is still extensive research and testing to be done with more samples of the Tattykeel Aussie White as the preliminary work was based on only randomly selected samples. The results of this work has not yet been published, but the methodology used for the sensory evaluation of eating quality, intramuscular fat content, melting point and fatty acid composition in the muscle tissues of sheep and beef cattle can be found in the following peer-reviewed journal papers from Assoc. Prof. Aduli’s research group.
1. Flakemore AR, Malau-Aduli BS, Nichols PD, Malau-Aduli AEO 2017. Omega-3 fatty acids, nutrient retention values, and sensory meat eating quality in cooked and raw Australian lamb. Meat Science 123 (1): 79–87. doi:10.1016/j.meatsci.2016.09.006
2. Nguyen DV, Flakemore AR, Otto JR, Ives SW, Smith RW, Nichols PD, Malau-Aduli AEO 2017. Nutritional value and sensory characteristics of meat eating quality of Australian prime lambs supplemented with pelleted canola and flaxseed oils: Fatty acid profiles of muscle and adipose tissues. Internal Medicine Review 3 (3): 1-21http://internalmedicinereview.org/index.php/imr/article/view/295
3. Malau-Aduli AEO, Holman BWB, Kashani A, Nichols PD 2016. Sire breed and sex effects on the fatty acid composition of heart, kidney, liver, adipose and muscle tissues of purebred and first-cross prime lambs Animal Production Science, 56 (12): 2122-2132 http://dx.doi.org/10.1071/AN14906
4. Malau-Aduli AEO, Edriss MA, Siebert BD, Bottema CDK, Deland MPB, Pitchford WS 2000. Breed differences and genetic parameters for melting point, marbling score and fatty acid composition of lot-fed cattle. Journal of Animal Physiology and Animal Nutrition 83 (2): 95-105, doi: 10.1046/j.1439-0396.2000.00254.x
5. Malau-Aduli AEO, Siebert BD, Bottema CDK, Pitchford WS 1998. Breed comparison of the fatty acid composition of muscle phospholipids in Limousin and Jersey cattle.Journal of Animal Science 76 (3): 766-773, doi:/1998.763766x
6. Malau-Aduli AEO, Siebert BD, Bottema CDK, Pitchford WS 1997. A comparison of the fatty acid composition of triacylglycerols in adipose tissue from Limousin and Jersey cattle. Australian Journal of Agricultural Research 48 (5): 715-722, doi:10.1071/A96083