Besides lean meat powder, what other safety hazards are there in American beef?
Editor's note: This article was written by Su Chung-ching, professor emeritus of the Department of Biochemical Science and Technology at National Taiwan University, and provides a comprehensive scientific analysis of the issues and pros and cons of American beef. He points out that American cattle are raised on grains such as corn, which can greatly shorten the time invested in feeding, and doubles the beef cutting yield; intermuscular fat increases and the meat becomes tender, so the economic benefits are very high. However, this practice also gives rise to many problems, summarized as follows:
1. The current American beef industry was built on the use of drugs to control "corn-fed cattle disease" and to enhance meat production. Feeding on grains violates the physiology of cattle, causing pathological changes in the animals and increasing pathogenic E. coli in their waste. Therefore drugs must be used for control, with feed additives such as antibiotics, hormones and lean meat powder (ractopamine) used in combination at different stages.
2. The problem of antibiotic use is in fact more serious than that of lean meat powder. Antibiotics select for bacteria carrying "resistance genes." In addition, the antibiotics used for corn-fed cattle easily produce special pharmacological effects, such as cardiac arrest. Different animals also have different metabolic mechanisms and toxicity, making it difficult to infer the effects on humans. Moreover, intensive confinement increases the chance of pathogen contamination and raises the probability of cross-contamination of carcasses.
3. So-called "residue testing" will have different "sensitivity" depending on the sampling amount, separation recovery rate, instruments and testing methods. To implement import inspection, standard operating procedures must be a prerequisite, along with clear scientific evidence.
4. Finally, the author points out that the government has a responsibility to clearly label the country of origin, nutritional content (fat content) and additive residue levels, so that consumers can make their own choices.
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The import of American beef has become a public controversy. Earlier there was doubt about how high the probability of mad cow disease transmission to consumers was, and now there is the dispute over whether ractopamine, which is banned domestically, should be permitted. American beef contains ractopamine, and just like the mad cow disease that spreads among cattle, it is a consequence of the use of feed in modern industrialized cattle raising, yet no appropriate analytical reporting has appeared in the media. Although the author's specialty is not animal husbandry science, based on knowledge of biochemical nutrition and general life science, he is willing to offer some humble views as a reference for consumers and policymakers.
Cattle are typical herbivores
Herbivores with ruminant stomachs, aided by the digestive action of microorganisms in the stomach, can convert grasses that other higher animals cannot use into nutrients. The herds of cattle seen in the well-known American western cowboy movies can all be raised to marketable size just by eating grass and drinking water. However, generally pasture-raised, grass-fed beef cattle take three to five years to mature to a marketable weight of about 300 to 500 kg. Although this has the advantage of lower fat content compared with beef from modern confined feeding operations that use grain feed, it is criticized for being tougher and less palatable (not tasty), requiring long-term investment because of the slow feeding period, and needing large land investment with low economic efficiency.
"Confined feeding" with grain feed violates the nutritional physiology of cattle
After World War II, the United States, with a large surplus of corn production, began researching and developing techniques for raising cattle in confinement on feed composed mainly of grains, especially corn. The basic nutritional needs of animals are fairly consistent, but their food sources are limited by environmental factors, so their feeding habits and the digestive physiology of their food differ under the influence of their evolutionary environment. Ruminants such as cattle and sheep are a typical group very different from humans.
The main component of grains is starch, and starch is an easily digestible polysaccharide, whose nutritional physiology differs greatly from the slow digestion and absorption of the grass fiber that ruminants are adapted to. In the digestive tract of cattle, the rapid digestion of starch quickly raises the amount of glucose in the rumen (the first stomach of ruminants). Because the absorption system is accustomed to slow digestion and cannot absorb and remove it in time, it causes abnormal fermentation by microorganisms in the digestive tract, producing large amounts of several organic acids and gases, resulting in "rumen acidosis" and flatulence, raising blood sugar and acidity levels and leading to many pathological conditions. It also changes the acid tolerance of coliform bacteria in the intestine, increasing the probability that pathogenic E. coli (E. coli O157:H7) appears in cattle feces; and because the terminal confinement environment is less sanitary, it may raise the probability of vector contamination of carcasses.
Although raising cattle on grains has the short-term benefit of rapidly increasing the body weight of beef cattle or the milk production of dairy cows, if corn is fed for a long time without medical treatment, not only will all livestock benefits disappear, but pathological conditions will worsen and lead to death; all of this is reported in detail in animal science literature. The grain-feeding pathological conditions explained above will occur regardless of cattle breed.
Because of the serious problems described above, after weaning, calves are raised on pasture for a period before entering a grain feedlot for fattening for the 110 to 150 days before slaughter, during which the cattle's body weight can increase by about 50%.
American cattle-raising technology that overcomes "corn-fed cattle disease" with drugs
The United States is a country with advanced science and technology, so of course much research has been done on the physiology and pathology of corn-fed cattle and corresponding strategies. The most complete account of its course and achievements is the comprehensive report "Fifty years of pharmaceutical technology and its impact on the beef we provide to consumers" published in 2004 by Thomas E. Elam and Rodney L. Preston. Searching Google with the keywords pharmaceutical technology and beef will immediately find this article.
From the title of this article it can be inferred that the current American beef industry was built on the use of drugs to control "corn-fed cattle disease" and to enhance meat production. Briefly put, the control of corn-fed cattle disease mainly uses the elimination or weakening of the microorganisms that cause rumen acidosis, and the agent used is a class of antibiotics called ionophores; before confinement, hormones are used to accelerate growth; to raise carcass meat yield and control excessive fat production, the physiological regulator ractopamine is added in the later stage of confinement; methods of drug use include hormone implants and feed additives; feed formulas and drug use are designed in strict coordination with the physiological characteristics of cattle at different growth stages, and electronic tags and computers are used for feeding management.
Thus, fifty years of research and development technology achieved a shortened feeding period of two years, doubled the beef cutting yield of a single animal, increased intermuscular fat and made the meat tender, giving it rich aroma and good taste when grilled. According to the USDA beef grading standards, most of it can be classified as high-grade beef, so the economic benefits can be said to be very great.
The harm of antibiotic misuse
Antibiotics used as feed additives can reduce the disease rate of livestock and also improve feed utilization. In the era when Taiwan's agricultural administration was led by the "Rural Rehabilitation Committee," American Cyanamid set up a factory in Taiwan to produce the feed additive "Aureomycin" (also known as chlortetracycline) containing aureomycin, which became popular for a time, showing that "non-therapeutic antibiotic use" in Taiwan's livestock industry also has a fairly long history.
Antibiotics are bactericidal or bacterial growth-inhibiting agents produced by microorganisms. Their large-scale use in treating human disease began with "penicillin" during World War II. Many antibiotics are now registered for medical use, and they are very effective drugs for treating infectious diseases, once revered in Taiwan as "miracle pills." Their use was originally limited to hospitals, but what impact occurs when they are introduced into the broader environment as veterinary drugs or feed additives?
When microorganisms come into contact with antibiotics, those without resistance die, but bacterial cells carrying "resistance genes" survive. These resistance genes exist in small circular DNA called plasmids, which can spread among bacterial cells by horizontal infection and can also multiply by vertical inheritance. Plasmids are not the main hereditary DNA of bacteria, and multiple copies can exist within a single bacterial cell; the more copies there are, the stronger the resistance.
Thus, antibiotics present in the environment become a selection factor for resistant bacteria, and the more widely antibiotics are used, the more the distribution range and resistance of resistant bacteria increase, reducing the opportunity to treat human diseases caused by such bacteria with antibiotics. This is the reason why our Bureau of Animal and Plant Health Inspection and Quarantine, in its "Regulations on the Use of Medicated Feed Additives," stipulates that antibiotics shared by humans and animals should not be used as feed additives.
However, there are many kinds of antibiotics with diverse pharmacological actions, and how the use of a certain antibiotic as a feed additive affects human health indirectly and directly is a proposition that can only be concluded with quite advanced public health expertise. Even so, it is common knowledge among modern people that diseases infected in hospitals where antibiotics are heavily used (generally called nosocomial infections) are more difficult to treat with antibiotics.
Based on the above points, regarding the import of beef, its safety and consumers' choices, the author offers his humble views and suggestions as follows.
The necessity of imported beef
Religion and ethnic customs have a considerable influence on the choice of animals for food; for example, Muslims absolutely do not eat pork, and Jews do not eat scaleless eels and catfish. The cattle the author saw in Taiwan as a child were either water buffalo used for plowing fields or yellow cattle used for pulling carts, and there was no farming industry for beef cattle or dairy cattle. At that time, ordinary Taiwanese people did not eat beef; the reason heard from elders was that draft cattle ate only grass and toiled hard, and out of gratitude for their contribution to humans, people could not bear to slaughter and eat them.
After World War II, the Japanese who had the habit of eating beef left Taiwan, but new immigrants who consumed beef, represented by beef noodles, arrived. Subsequently, with economic and foreign trade development, food diversification was a natural trend. The supply of beef could of course also be considered domestically produced, but it requires large areas of grassland and long periods of pasture-raising beef cattle, which is a livestock method that cannot be sustained in Taiwan, a country with a small territory; pasture-raising plus American-style confined fattening technology is of course also not feasible. Although there is now a small amount of domestically produced beef, it simply cannot meet demand, and not importing would be unfair to the public who like to consume beef. If we affirm that beef imports meet the needs of Taiwanese society, then of course we should choose a source of beef that is cheap, tasty and safe.
Safety is the first requirement of food quality: strengthen inspection of imports
Before entering this topic, let me first point out two problems of incorrect wording or lack of caution in newspaper reports concerning feed additive residues.
Pig farming in our country bans ractopamine. Ractopamine is a synthetic chemical substance and does not exist in plants or animals. Therefore, Taiwanese pork produced in accordance with the law banning ractopamine will not have ractopamine "residue"; only Taiwanese products used illegally and imported meat used legally will have disputes over "residue levels."
The use of the phrase "must not be detected" can only be correct if the background of the testing technology is understood. Food testing includes chemical and physical methods. "Residue testing" in food mostly first processes the sample to extract the substance to be tested, then directly or further separates it by chemical or physical methods, and uses specific spectra or reagents to reveal its quantitative state to achieve the testing purpose. In such a series of testing processes, the extraction step has issues of sample amount and separation recovery rate, and the instruments and detection methods used differ, giving rise to different "sensitivity" problems. Therefore, the standard of "must not be detected" must be premised on the designation of a standard sampling amount and testing method, because insufficient sampling amount or sensitivity will both underestimate the actual content and lead to the error of judging a product as qualified.
If the government permits the import of American beef produced with ractopamine, it must at the same time permit our country's livestock industry to also use ractopamine, in order to maintain the fairness and balance of laws and regulations, and set an acceptable residue level with a clear scientific basis, so that the public understands the legitimacy of the policy change. According to data found in the literature, the lean meat powder ractopamine is rapidly metabolized and eliminated in cattle and pigs, and the allowable residue levels set by the United States are consistent with the views of the United Nations Codex Alimentarius Commission, which should serve as a reference basis for the policy change.
The advantage of rapid metabolic and excretory elimination means that American agricultural authorities do not set a deadline for banning ractopamine before slaughter, and if it is not used continuously, the benefit gained from its use quickly disappears; this is the reason why much Taiwanese-imported American beef is found to have ractopamine residues.
What policymakers must note is that, according to the author's observation, our country's pig farmers oppose American beef imports by using "banning versus not banning ractopamine" as the basis for distinguishing domestic from American meat products, with the aim of realizing their position against opening the "pork market that domestic production can already satisfy" to imports. As far as the ractopamine controversy is concerned, only by integrating the issues of beef and pork imports can a solution consistent with scientific principles be proposed. A plan that separates beef and pork will probably have to rely on political wisdom beyond the author's imagination.
From the standpoint of food safety, the author believes antibiotics are a more worrying problem than ractopamine. The pharmacological action of the antibiotics that must be used to produce corn-fed cattle is quite special, and this has been cited as the basis for inferring that microorganisms will not develop the aforementioned resistance. Biological cells or organelles have an outer membrane, and the electric potential difference produced by the cation concentration difference on the two sides drives many biological physiological functions. The pharmacological action of the antibiotics used in raising corn-fed cattle is to eliminate this potential difference and stop the physiological functions it drives, such as the heartbeat of animals.
Because of this pharmacological action, this class of antibiotics cannot be used to treat human infectious diseases. To avoid the direct harm of antibiotic residues, it is absolutely necessary to set allowable residue levels for imported beef that suit national conditions. Another special feature of this class of antibiotics is that their mechanisms of absorption, metabolism and excretion and their toxicity differ among different animals. Taking the most widely used monensin as an example, the LD50 (the dose lethal to half of the test animals, mg/kg body weight) for horses, cattle and chickens is 2 to 3, 20 to 80, and 200 respectively. Comparing only these three kinds of livestock, the toxic dose differs by a hundredfold; how to extrapolate to obtain a safe allowable value for humans should not be an easily solved proposition.
In cattle, the main absorption site is the rumen; after entering the liver, it is sent through the bile duct into the small intestine and excreted in the feces. Therefore, the residue levels in these internal organs should all be higher than in muscle. If the import of internal organs is permitted, residue control must be given special attention.
Besides antibiotic residues, intensive confinement also increases the chance of pathogenic bacterial contamination, so bacterial contamination testing must also be strengthened. In addition, producers should be required to provide production records, and allowable residue levels should be set for all drugs they use, as a basis for mediation when disputes arise. According to the literature, every cow in the United States has individual production record data, so adopting such a control system should not be an excessive demand. Personnel must be sent to inspect and understand the operating conditions of the upstream and downstream facilities related to shipping, including calf and intermediate cattle farms, finishing feedlots, slaughterhouses and cutting and packaging plants, to obtain the necessary information for communication and for pursuing responsibility when problems occur.
Consumers' beef choices
Food is a substance necessary for sustaining life, but consumers' choices may differ considerably depending on their values and consumption patterns (boiling, pan-frying, grilling, eating raw). Taking imported beef alone, when there is a choice between American corn-fed cattle and Australian grass-fed cattle, the former has the double drawback of high total fat and saturated fatty acid content but low content of "nutritionally essential unsaturated fatty acids." However, if one considers good eating sensation and calculates from a year's intake, the fatty acid advantage of grass-fed cattle is not significant, because when eating a little less fish oil capsules can make up the unsaturated fat difference, choosing corn-fed cattle cannot be said to be wrong. On the other hand, when adhering to the old teaching of "not eating the meat of sick animals" (the author received such a family teaching) and regarding corn-fed cattle as pathological cattle kept alive by drugs, the opposite choice also cannot be said to be wrong.
Recently I went to a hypermarket and found a large billboard in the store promoting whole boxes of Australian-produced, grain-fed beef, showing that Taiwan's beef market has already influenced Australia, the main base of grass-fed cattle production, to also modify its production methods to please consumers who like grain-fed cattle. On the other hand, information on a website shows that in the United States, the main base of corn-fed cattle, although the output value of grass-fed beef cattle once declined to only 15% of the total value, in recent years it has rebounded to 20%, and the reason should be that part of the consumers have already developed doubts about the safety of corn-fed cattle.
Not all consumers are experts in food science or biological science, and a large proportion of consumers are not the direct food purchasers who go to hypermarkets. Therefore, the government's responsibility is to take the safety-related scientific data on which import decisions are based and turn it into public information in plain language for all citizens, and, in accordance with fresh food labeling laws, in addition to existing labels, add safety-related labels such as country of origin, nutritional content (especially fat content) and additive residue levels, as indicators for consumers' beef choices.
Conclusion
Although regarding the use of ractopamine, the Japanese government has adopted a dual standard that is inconsistent domestically and internationally (which the author dares not endorse) to buffer the problem of American beef imports, the author's earliest knowledge of the actual state of corn-fed cattle raising came from a program recently broadcast by Japan's public NHK satellite television and produced by an American university, showing that the publics of both the United States and Japan are quite concerned about the consequences of grain-fed cattle raising.
To write this article, the author did a lot of Google searches; because American beef is a domestic controversy, most of the materials found came from the United States, but there were also a few Japanese technical reports on residue testing. The nature of the reference materials included official reports, scientific and technological literature from academia, and expressions of public opinion on websites. Probably because of their duties, official and pharmaceutical industry reports all praise the economic contribution to the livestock industry. From academic reports one can gain a deeper understanding of the truth behind the occurrence of pathological cattle. The voices abandoning corn-fed cattle for grass-fed cattle mostly come from public opinion web pages; I also saw news reports of importing grass-fed cattle from Australia and New Zealand to make up for insufficient domestic American production. Comparing this with the actual situation of Taiwan importing grain-fed cattle from Australia, one feels that beef is really not a food that can be fully covered by the simple word "beef."
Judging from the structure of the human digestive system, human feeding habits are omnivorous, but a vegetarian diet can also maintain health, as evidenced by long-lived vegetarians. As mentioned above, humans' meat choices are influenced by cultural factors such as beliefs and ethnic customs. Using drugs to force herbivorous animals to become omnivorous animals in order to produce gourmet beef that meets market demand is, like using genetic engineering technology to create genetically cloned organisms (GMOs), a remarkable biotechnology achievement.
In the late 1950s, during the author's stay in the United States, he read Aldous Huxley's Brave New World and received a great cultural shock. Although corn-fed cattle and GMO crops are agricultural applications of biotechnology, and are completely different from what Huxley's novel describes, namely the use of "cloning" human reproductive technology to change the population composition and operating mechanism of human society and overturn traditional values, the fact that both technologies have an impact on cultural values related to religion and belief, and therefore encounter regional rejection, should not be ignored.
In addition, it must be pointed out that, besides the positive economic benefits of improving meat quality and feed efficiency, corn-fed cattle technology also has the positive environmental benefit of reducing cattle emissions of methane, which has a greater greenhouse effect than carbon dioxide. At a time when, from the concept of the "carbon footprint," urging industry to reduce greenhouse gas output has become a global consensus, this fact will be one of the chips supporting grain-fed cattle raising.
Finally, the author presents two items from the collected materials that may have reference value. First, in the caution notice issued by the manufacturer of the lean meat powder ractopamine to users, it is stated that workers engaged in mixing feed with ractopamine must wear full protective clothing and put on precision-grade masks and eye protection, and those with a history of cardiovascular disease must not come into contact with it. Therefore cattle farmers have raised doubts about whether a toxic substance requiring such protection is safe to ingest through beef. Second, not all American pig and cattle farmers use ractopamine; therefore, if a ban on ractopamine is insisted upon, there should be the option of importing only from producers who do not use it.
[Editor's note: After this article was finalized, Executive Yuan spokesman Yang Yung-ming announced on March 5 that, based on the conclusions of an expert meeting's assessment, the Executive Yuan proposed a sixteen-character policy direction: "safe tolerance, separation of beef and pork, mandatory labeling, exclusion of internal organs." It will first fully communicate with all sectors before deciding the timing of lifting the ban.]
(Originally reprinted from Science Monthly, issue 363, March edition)
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