Most cattle feeding strategies in North America include hormone implants even though organic consumers and the European Union have reservations about their use.
But the hormonal growth stimulants are misunderstood, even by cattle producers, experts say.
Gary Robinson of Great Northern Livestock Consulting of Westlock, Alta., said the need to use the implants is obvious. He specializes in cattle feeding strategies, supervising the nutrition and development of more than 100,000 animals daily. He said implants add more than $70 to the value of each slaughter animal.
The higher value comes from improved feed efficiency and increased average daily gain and is “often the difference between making money and not” in the cattle feeding business.
Read Also
StatCan stands by its model-based crop forecast
Statistics Canada’s model-based production estimates are under scrutiny, but agency says it is confident in the results.
Robinson told those attending last week’s Western Canada Feedlot Management School in Saskatoon that he recommends every feeder use them, and most do.
“We’ve used them for 30 years or more and our government approves them as safe,” he said.
European markets limit North American imports of beef due to fears that increased hormone levels may appear in meat or in feces that end up in ground or surface water.
Guy Gamberg of Schering-Plough in Calgary said there have been no scientific studies that show significantly increased levels of hormones in meat produced with implants.
The majority of beef cattle produced in North American over the past 30 years have been produced using hormone implants.
Androgens are used to build muscle and aid the body in replacing testicle-produced testosterone lost by castration. Estrogens boost growth hormone production and, along with progesterone, control the female estrus cycle, channeling feed resources from reproduction into meat production.
As recently as 1999, the World Health Organization approved the use of five hormones in beef production – testosterone, progesterone, estradiol, zeranol and trenbolone acetate.
Early-age implants are done using an estrogenic implant that stimulates the growth of muscle and bone structures by stimulating the pituitary gland to produce more of the animal’s own growth hormones.
“We are placing tiny, trace amounts of estrogen or zeranol, an estrogen-like molecule, in the ear, the only spot on a beef animal that doesn’t enter the food chain someplace … it stimulates the animal’s pituitary gland to produce more of its own growth hormones,” he said.
Jean Lundquist of Intervet Canada in Sask-atoon agreed.
“It’s not like we are filling these animals full of steroids to make them do something they don’t do naturally. We’re not adding hormones to the meat or even causing large amounts of the animal’s own (hormones) to be deposited (in the meat). In steers, we replace some of what is lost in castration … in heifers, it simply levels out their hormone levels, balancing their behaviour, letting them eat and gain steadily,” he said.
Gamberg said eight-ounce cuts of beef steak, produced with or without the use of implants, contain two to three nanograms, or two to three billionths of a gram, of estrogen.
“A glass of milk contains 35 ng, a serving of peas 336 ng. An egg contains 1,750 ng. An adult male (human) produces in his own body 136,000 ng. An adult female 480,000 ng. If she is pregnant, she produces 20 million ng,” he said.
“Two nanograms (of estrogen) present in beef isn’t likely going to cause me to lose my beard or suddenly start talking higher when I’m kicking out 136,000 every day. That is the challenge of communicating this issue to the public,” he said.
Hormones in meat are destroyed by digestion in the human stomach and filtered through the liver, according to the international Society for Endocrinology.
The WHO expert committee on food additives reports that implanted beef may contain slightly elevated levels of estradiol.
At the highest allowable implant limits, cattle can produce beef with an additional residue level of 30-50 ng of estradiol per 500 grams of meat.
The committee reported a 60 kg person has an acceptable daily intake of estradiol of 3,000 ng per day, so the additional estradiol in the large portion of meat from the implanted animal would represent 0.16 percent of the allowable daily total.
Gamberg said hormone use in beef makes the public think of professional athletes abusing hormones to create abnormal growth.
“(Beef produced with growth stimulants) is normal development being balanced out for efficiency by relatively tiny amounts of (hormones),” he said.
