A variety of alternative growth promoters have been marketed as natural replacements for conventional productivity-enhancing technologies.

Can we replace growth promotants?

Research on the Record with Reynold Bergen

Hormone implants and feed additives such as ionophores (e.g. monensin/Rumensin), beta-agonists (e.g. ractopamine/Optaflexx) and MGA (to suppress heat in heifers) have allowed Canada’s feedlot sector to dramatically improve growth rates, feed efficiency and environmental performance. In-feed antimicrobials to prevent liver abscesses (e.g. tylosin) also have an indirect benefit because healthy cattle grow better. While consumers […] Read more

How long do growth promotants persist in soil and manure, and is there a risk they could enter surface or groundwater?

Growth promotants and the environment

Research on the Record with Reynold Bergen

Growth promotants dramatically improve the growth rates and feed efficiency of beef cattle. Trenbolone acetate (TBA) behaves like testosterone and is used in several feedlot implants (Component, Revalor and Synovex). Melengestrol acetate (MGA) behaves like progesterone, a pregnancy hormone. Some feedlots feed MGA to suppress estrous cycles and riding activity in heifers until a few […] Read more


Taste-testing during a Canadian Beef Advantage Seminar in Shanghai in 2013.

Devil’s in the detail of China-U.S. beef deal

The announcement on May 4 that China will start accepting U.S. beef on or before July 16 had U.S. industry leaders applauding the Trump administration and excited about supplying this giant market. Their enthusiasm was understandable — U.S. beef has been shut out of China since late 2003, when the U.S. reported its first BSE […] Read more

feedlot cattle

Performance-improving product approvals for livestock

Research on the Record with Reynold Bergen

Last month’s column summarized a North Dakota State University research project where young female pigs were fed burgers made from tofu or beef from naturally raised or implanted cattle to see whether they reached puberty sooner. They didn’t. That is no surprise, because researchers, pharmaceutical companies and government regulators invest a lot of time, effort […] Read more


Seeking Credibility

Two recent events jumped agriculture’s role in the antimicrobial resistance merry-go-round into high gear. First was the Food and Drug Administration’s (FDA) Final Guidance 213 (December 2013) that established a three-year time frame to end the use of medically important antibiotics as growth promotants. There were also new rules on veterinary oversight related to antibiotic […] Read more