The ban, particularly in China, prompts researchers to look for proof that the product is safe for use in food animals
HOUSTON, Texas — There is considerable interest in doing business with China, but there are barriers that some meat traders find difficult to hurdle.
The Chinese do not allow the use of growth promoting hormones and beta agonists, so research is under way to prove they are safe for use in food animals.
“When you combine those technologies in production, they clearly improve the efficiency of growth,” said animal scientist Keith Belk of Colorado State University.
Seventy to 80 percent of feedlot cattle receive the feed additive ractopamine, and about 95 percent are implanted with growth promoting hormones. It would cost $150 per head if these products were not used.
Beef products are tested for residues at the port of entry, and retail meat may be rejected if results are positive.
The United States wants the Chinese to follow minimum residue level standards set by the World Organization for Animal Health or Codex Alimentarius, which regard the products as safe. However, a series of food safety scandals forced the Chinese government to crack down on domestic producers, and it will not offer different standards to other countries, said Belk.
Working with Texas A & M University, Belk and other researchers have been commissioned by the U.S. Department of Agriculture to look at compound residues.
The Chinese disallow 146 compounds, including estradiol, progesterone, testosterone, MGA, zeranol and ractopamine.
“There is a zero tolerance policy for all of them. They are even more restrictive than the European Union,” he said at the International Livestock Congress held in Houston late last month.
Researchers want to know if the products deplete over time.
Work is ongoing but they have already learned ractopamine residues might show up in feed grade tallow.
Tallow feeding is conventionally done in feedlots and contains 0.8 to 50 parts per billion, so ractopamine could possibly show up in non-hormone treated (NHT) cattle.
“Many of the cattle in those NHT programs in the United States are fed tallow because nobody knew this was a problem,” he said.
“We could be feeding tallow that by virtue of the fact it is recirculating ractopamine … could cause tissues in those cattle to be positive.”
As well, they are checking to see if cross contamination from livers and intestines could occur at the packing plant.
Research is also measuring ractopamine withdrawal times. The product is fed for 28 days prior to shipping.
“From the study, we know if we withdraw cattle from ractopamine for two, four or seven days, we can, depending on the tissue, reduce the residues, particularly below the (minimum residue levels) that have been established,” he said.
“The omasum, small intestine and large intestines are problematic for us.”
Companies exporting these items may have to reconsider their business plans.
Another problem is the presence of the growth promoter zeranol in animal tissues.
Zeranol can occur naturally in fusarium-infected grain.
“You can see about 50 percent of the time when mould was growing, you can detect zeranol, even when the cattle weren’t treated with zeranol as a Ralgro implant,” he said.
“This can be a problem relative to exports.”
In Canada, feedlots do not use ractopamine if a packer contract requires untreated cattle. Not using the product reduces the value of the carcass by $15 to $30, but the packer offsets that loss with a premium.
“We have learned the feedlot needs to go off the beta agonists altogether and not have it on the site. It has been very difficult to achieve racto-free unless the product is not being used on the site,” said veterinarian Kee Jim of Feedlot Health Management Services in Okotoks, Alta.
These products require careful planning in the feeding regimen, and Jim does not believe it is possible to withdraw it and then market the cattle as residue free.
“It is a biological system. You either don’t use it at all in the feedlot or it is fairly difficult to manage the other way. It is theoretically possible, but I haven’t seen much success with that,” he said.
The product can be more concentrated in certain tissues, but the levels can be measured at very low amounts — parts per million or parts per billion — depending on the testing methodology used.