7 replies to this topic

[Shalmanese]

Slate has an article on how Beef is being fed a growth drug, Zilmax to increase the lean muscle mass at the expense of flavor and marbling.

This seems like a pretty distressing trend. Does anyone have any more information about this?

[rotuts]

so pics of the Beef:

http://www.wtamu.edu...taagonistsd.pdf

[DiggingDogFarm]

It's nothing new, growth stimulants have been used in the production of beef for quite some time.
The solution is simple, don't buy questionable beef.

Know your grower!!!!!!


~Martin

[Mjx]

After reading the article, which mentions that Zilmax was originally developed as a drug to treat asthma in humans, I did a search to see what side-effects it has, and there seem to be no current references to this use. Now I'm wondering whether it has been pulled for human use for any reason (I checked for the compound name, zilpaterol hydrochloride, in hopes of getting a broader overview). Anyone else find something in google scholar?

[gfweb]

Its a beta-agonist, meaning it mimics the effect of adrenalin on beta receptors. Why this causes weight gain I can't figure. It doesn't appear to be a hormone. I'll poke around some more.

[DiggingDogFarm]

Here is another article:
"As Beef Cattle Become Behemoths, Who Are Animal Scientists Serving?"
By Melody Petersen
http://chronicle.com...-Become/131480/


~Martin

[jmolinari]

Sounds like ractopamine, which goes by Paylean, in the pig industry...builds muscle at the expense of fat as well as various neurological and physiological problems in the pigs.

[Keith_W]

After reading the article, which mentions that Zilmax was originally developed as a drug to treat asthma in humans, I did a search to see what side-effects it has, and there seem to be no current references to this use. Now I'm wondering whether it has been pulled for human use for any reason (I checked for the compound name, zilpaterol hydrochloride, in hopes of getting a broader overview). Anyone else find something in google scholar?

Physician here.

This is correct. Zilmax is Zilpaterol, which is a long acting beta-agonist. An "agonist" means that it stimulates a certain receptor, in this case Beta-receptors. Beta receptors are part of the autonomic nervous system, which you may have learnt in school as part of the "flight or fight" response. In addition to dilating lung bronchioles, beta agonists also make the heart beat stronger and faster, stimulates the pancreas to release Glucagon (which in turn makes the liver convert glycogen to glucose, freeing up energy to be used), and diverts blood flow from non-essential organs (e.g. intestines) to muscles. Overdosage will result in cardiomyopathies (disease of the heart muscle due to chronic overstimulation), hypertension, disturbed sleep patterns, psychiatric phenomena, and wastage of the organs which are deprived of blood flow.

As a doctor for humans, obviously my focus and my way of thinking is quite different to how a feedlot scientist might think. When I prescribe a long-acting beta agonist, my concern is to use the minimum dose required to achieve the desired effect (relief and prevention of asthma), whilst minimizing the side effects. I would imagine a feedlot owner couldn't care less if his cows were awake and suffering from nightmares (or should I say nightcattle?) all night or suffering from high blood pressure. What matters to them is the delivery of a quality product with no toxicity.

Given that I do not routinely sample the meat of my patients, I can not comment if the quality of the meat is different, nor do I know if the nutritional value of the meat has been changed. But - if you are wondering if you can be affected by ingesting beef which has been treated by this drug, I am pretty confident that it is safe on theoretical grounds.