How does marbling develop?
How does marbling develop? - Beef CRC - Beef Genetic Technologies
 An experiment which aims to determine what role nutrition plays in the development of marbling in beef cattle is underway at the Glen Innes Research station.Paul Greenwood from New South Wales Department of Primary industries is leading the Beef CRC project which will help researchers better understand the nature of fat deposits and whether they are biologically different. Dr Greenwood said the experiment will look at how different fat deposits develop and whether a strategic nutritional supplement during the early post-weaning period can influence the way fat develops. There are three main types of fat deposits in beef cattle. These include sub-cutaneous fat (outside fat), intra-muscular fat (marbling) and inter-muscular fat (the fat between muscles). While Dr Greenwood said animals must have adequate amounts of all fats to survive, grow and perform, excessive fat is un-desirable. “There is often a high degree of wastage and inefficiency when it comes to removing excess fat from carcasses,” said Dr Greenwood. “There is usually a fat specification that producers try to target. If they produce cattle with excess fat or inadequate fat they can be penalised financially.” “We want to see if we can improve marbling development without affecting the other fat deposits.” Marbling or Intra-Muscular Fat (IMF) is highly desirable in some export markets including Japan. “In a general sense we know there are certain genotypes which are pre-disposed to marble more than other animals. We also know that as animals age they tend to develop more IMF,” he said. “What we don’t know is whether there is anything we can do at a nutritional level to change or enhance marbling.” Dr Greenwood said the cattle used during the experiment can be classified into several broad genotypes. “One group of cattle is high marbling but is also likely to deposit high levels of sub-cutaneous and inter-muscular fat. Another group is also a high marbling genotype but will deposit less fat in the subcutaneous region,” he said. “The third genotype has less marbling but is pre-disposed to depositing more fat in the other regions. These different groups will allow us to look at the different fat distribution and marbling characteristics.” Half the animals will be fed a forage based diet, (pasture and forage based supplement) while the rest of the cattle will receive a pasture based ration with a high energy supplement. The cattle will be strategically fed for four months post-weaning. They’ll then be backgrounded for six months prior to entering the feedlot. One group will be fed for 100 days while the other group will be fed for 300. Dr Greenwood said there is no guarantee the experiment will have a positive outcome. But he added if they do discover a way to manipulate the biology and development of marbling it could have commercial significance. “Being able to strategically supplement cattle in the period when the animal is smaller and younger, ideally means the animals will hit their market specification earlier,” he said. “This would not only mean a potential saving in the amount of feed the animal needs but reduces the amount of time animals need to stay in the feedlot.” Dr Greenwood said they will also be tracking the impact of marbling or IMF on beef quality. “Earlier work indicates very high marbling genotypes can have a favourable effect on some of the lower-value cuts in terms of eating quality.” “We’ll be collecting scanning data at various points in the experiment. This will allow us to determine the effect of the treatments on meat quality along the way.” |
| To find out more about this research project contact Alison Betts, Communications Manager on (02) 6773 3795 or 0439 405 077. |
