In recent years use of the hormone to increase milk production has become an increasingly debatable topic for the dairy industry. Bovine growth hormone, or bovine somatotropin (also called bGH, rbGH, bST, or bST), help cows mature faster and produce more milk. The hormone is produced by cows' pituitary gland and an extra amino acid is attached before it's injected into dairy cows.
Though several nations, including all 25 European Union nations, Japan, Australia, New Zealand and Canada, have banned rBGH, the World Health Organization and U.S. Food and Drug Administration say that milk from rBGH treated cows is safe.
 Why should I be aware of this?
The potential health hazards to both cows and humans make rBGH controversial. According to the Center for Food Safety (and supported by a 2003 study published in the Canadian Journal of Veterinary Research), cows treated with rBGH suffer a 50 percent greater incidence of lameness (leg and hoof problems), 25 percent more udder infections (mastitis), and serious reproductive problems including infertility, cystic ovaries, fetal loss and birth defects.
Such health problems are likely to affect humans too and affect our disease resistance, as antibiotics used to fight infection can find their way into the milk that we consume.
 Hormone growth milk and health
Opposing groups in the US are demanding ban on bGH injections on the grounds that these hormones cause health problems like lameness, reproductive trouble, and udder infections in dairy cows. The antibiotics they are then treated with show up in the milk, especially because it usually takes longer to treat cows receiving bGH. The antibiotic residues also help create antibiotic-resistant bacteria, which is a serious, developing public health problem.
It is also feared that that bovine growth hormone injections may lead to the production of another hormone called insulin-like growth factor-1 (IGF-1). IGF-1 in increased dozes in the bloodstream could raise the risk for some cancers, particularly colon and breast cancers. according to research findings.
bGH manufacturers, however, claim that the presence of a little extra IGF-1 in milk is not harmful to health because — just like bovine growth hormone — IGF-1 is broken down by the human digestive system and never makes it into the blood. There are other studies which show that IGF-1 survives digestion and passes into the intestines.
 Other health concerns
Forced increase in milk production makes cows more susceptible to udder infections called mastitis, which can increase the amount of cow’s pus which ends up in the milk.
Mastitis is treated with antibiotics. This leaves more antibiotic residues in milk fed to consumers. Proponents of rBGH , however claim that antibiotic residues in the milk do not reach the consumer because each tanker of milk is tested for antibiotics and rejected if any residue is found.
 All about growth-hormone milk
Also referred to as recombinant bovine somatotropin, rBST is a synthetic variant of the naturally occurring hormone in the pituitary gland of cattle, which can be injected into a cow to increase milk production. rBGH is manufactured by Monsanto and sold to dairy farmers under the trade name POSILAC. Injection of this GE hormone forces cows to increase their milk production by about 10%. Monsanto and the US Food and Drug Administration (FDA) insist that rBGH milk is indistinguishable from natural milk and safe to cows and consumers.
However it is reported that Monsanto has been forced to admit to about 20 veterinary health risks on its Posilac label including mastitis and udder inflammation.
 What's rBGH?
- rBGH milk is contaminated by pus from mastitis induced by rBGH, and antibiotics used to treat the mastitis.
- rBGH milk is contaminated by the GE hormone which can be absorbed through the gut and induce immunological effects.
- rBGH milk is chemically and nutritionally very different from natural milk.
- rBGH milk is supercharged with high levels of a natural growth factor (IGF-1), excess levels of which have been incriminated as major causes of breast, colon, and prostate cancers.
- rBGH factory farms pose a major threat to the viability of small dairy farms.
 Ninty degrees
Many rBST proponents feel such labeling practices can mislead consumers into believing that milk made with the synthetic hormone, which typically costs less, is inferior.
With more and more consumers going for milk that comes from cows that are not treated with the artificial growth hormone, everyone from the largest to the smallest retailers started selling milk that is labeled as coming from cows not treated with the hormone.
According to some reports a third of the dairy farmers in the US inject cows with a hormone called Posilac. As a result cows produce an extra gallon a day thus bolstering the dairy farmers' production and bottom lines.
Drop in Milk Sale Feared
Because of fears of the hormone's safety it was feared that approval of the hormone by the FDA would result in a drop in the sale of milk and milk products.
 See Also
- New choices mean controversy for milk
- Bovine growth hormone milk does nobody good