All you meat lovers will be glad to hear Dr. Thomson say that steroid implants have no effect on beef quality, according to published research. More importantly, though, the meat is safe. The technology has been used since 1954 and there are strict guidelines and regulations in place to assure that neither human health nor animal health is negatively impacted. When compared to meat and milk that come from animals raised without hormones, the difference is…there is none. The USDA, the Academy of Nutrition and Dietetics and the Journal of Clinical Nutrition have all stated that beef from natural and organic programs is not safer, more nutritious, more wholesome or different in appearance compared to beef from animals that have received steroid implants. Aside from cooking the burgers at your next barbecue to the proper internal temperature , there’s no need for you to stress about the quality of regular beef and hormone-free beef!
How might behaviors affect hormones? The birdsong example demonstrates how hormones can affect behavior, but as noted, the reciprocal relation also occurs; that is, behavior can affect hormone concentrations. For example, the sight of a territorial intruder may elevate blood testosterone concentrations in resident male birds and thereby stimulate singing or fighting behavior. Similarly, male mice or rhesus monkeys that lose a fight decrease circulating testosterone concentrations for several days or even weeks afterward. Comparable results have also been reported in humans. Testosterone concentrations are affected not only in humans involved in physical combat, but also in those involved in simulated battles. For example, testosterone concentrations were elevated in winners and reduced in losers of regional chess tournaments.