Thuốc Siêu Nạc Ractopamine!!!

Ta Tưởng đâu chỉ có tụi TQ mới chơi thuốc siêu nạc, ai dè đâu Mỷ, Canada, củng chơi, nhưng mà chơi loại ít độc hơn, Ractopamine!!!
Trong khi rất nhiều nước trên thế giới đã cấm thuốc này kể cả TQ, nhưng anh Mỷ, và Canada lại cho sử dụng!!!

Trích:
http://usfoodpolicy.blogspot.ca/2012...e-in-pigs.html

Three views of ractopamine in pigs
Helena Bottemiller this week writes a thorough summary of the international trade controversies over U.S. exports of pork from pigs that have been treated with the growth promoter ractopamine hydrochloride. This animal drug is allowed under U.S. rules, but banned in many other countries, so U.S. trade negotiators have been pressing hard to get other countries to relent and allow small residues of the drug in imported pork.

Bottemiller describes the history of testing by the drug's manufacturer, Elanco, in terms that could leave a reader quite concerned:

The FDA ruled that ractopamine was safe and approved it for pigs in 1999, for cattle in 2003 and turkeys in 2008. As with many drugs, the approval process relied on safety studies conducted by the drug-maker — studies that lie at the heart of the current trade dispute.

Elanco mainly tested animals — mice, rats, monkeys and dogs — to judge how much ractopamine could be safely consumed. Only one human study was used in the safety assessment by Elanco, and among the six healthy young men who participated, one was removed because his heart began racing and pounding abnormally, according to a detailed evaluation of the study by European food safety officials.

When Elanco studied the drug in pigs for its effectiveness, it reported that “no adverse effects were observed for any treatments.” But within a few years of Paylean’s approval, the company received hundreds of reports of sickened pigs from farmers and veterinarians, according to records from the FDA’s Center for Veterinary Medicine.

USDA meat inspectors also reported an increase in the number of “downer pigs” — lame animals unable to walk — in slaughter plants. As a result of the high number of adverse reactions, the FDA requested Elanco add a warning label to the drug, and it did so in 2002.

The company also received a warning letter from the FDA that year for failing to disclose all data about the safety and effectiveness of the drug.

Some of the research literature is available on the USDA website, including this 2003 article by Marchant and colleagues, which indicates why there might be concern.

We found that there were differences in 24h behavioral time budgets, with the ractopamine-fed pigs being more active and alert and taking longer to lie down after being disturbed. However, these differences were only apparent during the first 2 weeks. In contrast, ractopamine pigs remained more difficult to handle over the entire 4-week period. At the end of the 4-week period, they also had higher heart rates than control-fed pigs and higher levels of circulating stress hormones.

We conclude therefore, that feeding ractopamine to pigs does affect behavior and physiology. Pigs that are more difficult to move are more likely to be subjected to rough handling and increased stress during transportation, implying reduced welfare, increased workload for the handlers and, potentially, poorer meat quality. However, for this conclusion to be applicable to the finishing pig population in general, other genetic lines should be tested.

I have been spending some time recently thinking about what makes many Wikipedia articles excellent, and also about the limitations of the free encyclopedia approach. Interestingly, the Wikipedia article on ractopamine is highly technical, as if written by an animal science expert, and generally downplays the safety concern. Although the Wikipedia article includes the Bottemiller article as one recent reference, its summary of the animal safety issue seems to contrast both with her article and with the Marchant article cited above. Here is the section in full:

Target animal safety

Ractopamine is safe for finishing pigs heavier than 240 pounds when administered in the diet at concentrations up to 10 ppm and fed for up to 35 days. However, there was an increase in the number of ractopamine hydrochloride-treated animals exhibiting signs of injury during the final drive to slaughter. (FDA)

I suppose the second sentence captures the animal health issues sufficiently? Of course, the great thing about Wikipedia is that articles are constantly changing and commonly improving.

Trích:
http://www.inspection.gc.ca/animals/.../1331129741124
Approved Brands

PAYLEAN 20 PREMIX contains ractopamine hydrochloride at 20 g/kg (Elanco).
OPTAFLEXX 100 PREMIX contains ractopamine hydrochloride at 100 g/kg (Elanco).

Approved for use

In meal or pellet feed for finishing barrows and gilts and finishing beef cattle and finishing heavy turkeys (toms and hens) only.

Note:

PAYLEAN 20 PREMIX is approved for use in swine (barrows and gilts) and heavy turkey (toms and hens) only.
OPTAFLEXX 100 PREMIX is approved for use in confined finishing beef cattle feeds only.

Approved Claims

For finishing barrows and gilts - Claims 1 and 2.
For confined finishing beef cattle greater than 400 kg body weight - Claims 3 and 4.
For finishing heavy tom turkeys in their last 14 days prior to slaughter - Claim 5.
For finishing heavy hen turkeys in their last 7 to 14 days prior to slaughter - Claim 6.
Claim 1: For increased carcass leanness, increased dressing percent, improved rate of weight gain and improved feed efficiency in finishing barrows and gilts.

Level of Drug: 10 mg/kg (0.001%) of the complete feed.

Directions:

Feed continuously as sole ration to finishing barrows and gilts, that are a minimum 70 kg starting body weight for no longer than six (6) weeks.

Note:

To obtain the performance benefits of ractopamine hydrochloride, diets should contain a minimum of 16% crude protein, or its equivalent obtained by amino acid (0.85-0.95% lysine) fortification. Dietary specifications should be determined in consultation with a recognized swine nutritionist (required on premix and supplement labels, only).

Warning:

Ractopamine hydrochloride is beta-adrenergic agonist. Individuals with cardiovascular disease should exercise special caution to avoid exposure to this medicated feed (required on premix and supplement labels, only).
When mixing and handling this medicated feed, use protective clothing, impervious gloves, and a dust mask. Operators should wash thoroughly with soap and water after handling. If accidental eye contact occurs, immediately rinse thoroughly with water. If irritation persists, seek medical attention (required on premix and supplement labels, only).
Keep out of reach of children (required on premix and supplement labels, only).

Caution:

Do not feed to breeding swine.
Do not feed to pigs intended to be retained for breeding.
Do not feed medicated feeds containing ractopamine hydrochloride for more than six (6) weeks.
The use of ractopamine hydrochloride in pigs finishing over 132 kg body weight has not been studied.
Pigs fed ractopamine hydrochloride may be at increased risk for exhibiting the fatigued or downer pig syndrome particularly when marketed at high body weights. Pig handling methods to reduce the incidence of fatigued or downer pigs should be thoroughly evaluated prior to initiating the use of this medicated feed.
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