marbling ability

knabe said:

http://www.beefresearch.org/CMDocs/BeefResearch/PE_White_%20Papers/Marbling%20-%20Management%20of%20cattle%20to%20maximize%20the%20deposition%20of%20intramuscular%20adipose%20tissue.pdf

Click to expand...

Thanks, knabe- that was exactly the paper I was reading yesterday. I accidentally closed the window and was hoping to find it again. This blurb is the kind of low carb human fat loss info I was applying to cattle. The irony is they advise eating plenty of fat from grass fed beef and grass fed butter.

Nutrigenomics and Beef Quality: A Review about Lipogenesis
http://www.mdpi.com/1422-0067/17/6/918/htm

Johnson said several cattle breeds in Japan, Korea and China are bred to have very high marbling content. To compare, USDA choice beef usually is about 6 percent intramuscular fat, where Japanese Wagyu cattle produce about 30-35 percent intramuscular fat. He added high-end steakhouses in the U.S. have a huge demand for prime steaks with marbling, and those usually have about 6-8 percent marbling.

Asian cattle, however, are fed for much longer periods of time, close to three years in fact, where U.S. beef breeds are usually raised and harvested for meat between 18 and 22 months of age.

Johnson said the longer cattle feed, the more they are able to replace saturated fats with unsaturated fats, such as marbling. Cattle release an enzyme called stearoyl-CoA desaturase, which takes steric acid, a saturated acid, and saturates it to form double bonds to convert it into oleic acid.

“As the animal matures, it gets fatter, has more days on feed, it increases the activity or this enzyme,” Johnson said. “So, in fact, we are creating more monounsaturated fat. The best way to get more oleic acid is to feed cattle longer.”

Johnson said the genetics of cattle breeds used in the U.S. simply won’t allow for marbling comparable to Asian breeds, although dairy breeds such as Holsteins, which make up about 20 percent of the beef cattle industry, do marble very well and without much backfat. U.S. beef producers would have to introduce Asian breeds to have cattle with high marbling, but because they feed so long it would not be economically feasible.
http://today.ttu.edu/posts/2016/05/steak-marbling

STEATOSIS/MARBLING DEVELOPMENT IN TRANSGENIC PIGS OVEREXPRESSING THE STEAROYL-COA DESATURASE GENE
Non Technical Summary
The combination of increasing age of the population with an increasing incidence of obesity and type II diabetes has led to a muscle dysfunction commonly known as steatosis. Although steatosis can indicate simple accumulation of lipid within muscle fibers, more recent evidence has demonstrated that steatosis also includes the invasion of muscle fasciculi with newly formed adipocytes. In animal production, this is known as marbling and is considered highly desirable in beef and pork products consumed in the U.S., Asia, and Australia. We propose the novel concept that steatosis in humans, and marbling in livestock species, is caused in part by the over-production of oleic acid in adipocytes, which acts as a trans-acting factor to promote the trans-differentiation of muscle satellite cells into marbling adipocytes. To address this hypothesis, pigs will be made transgenic to the stearoyl-CoA desaturase (SCD) gene with a ubiquitous promoter as well as in pigs in which the SCD gene is silenced. We will use these pigs, as well as pigs that have tissue-specific, temporally regulated SCD gene expression, in experiments in which pigs are fed diets high in saturated and trans-fats (beef tallow) or diets high in oleic acid (sunflower oil). In this manner, we will be comparing conditions in which SCD gene expression is maximally activated (SCD-overexpressing pigs fed saturated fatty acids) and when SCD gene expression is maximally depressed (SCD-silenced pigs fed oleic acid). This livestock animal model will mimic conditions in humans exhibiting steatosis, both in outcome and mechanism of action.
http://portal.nifa.usda.gov/web/crisprojectpages/1000780-steatosismarbling-development-in-transgenic-pigs-overexpressing-the-stearoyl-coa-desaturase-gene.html

So, I THINK what's going on is that preadipocite cells get induced (with insulin?) to differentiate into adipose fat cells instead of muscle. This is why early weaning and high energy ration increases marbling in end product? This is why high marbling cattle have reduced muscle?
And the general obesity epidemic in kids?
Eat all the fat you want and zero sugar for a week and see what happens.

Last thing...Angus is already spinning it, despite the studies concluding that age and management was more important than breed. Gotta admire Angus for working the system.
http://www.angusjournal.com/ArticlePDF/CAB%20Marbling%2010_08%20AJ.pdf