The Monsanto rBGH product, sold under the trade name Posilac, comes with an insert sheet containing information about the drug. The Posilac insert sheet says, in part, "Cows injected with Posilac are at an increased risk for clinical mastitis (visibly abnormal milk). The number of cows affected with clinical mastitis and the number of cases per cow may increase. In addition, the risk of subclinical mastitis (milk not visibly abnormal) is increased. In some herds, use of Posilac has been associated with increases in somatic cell counts." [11] Somatic cell counts are another name for pus in milk. The insert sheet mentions other health effects of rBGH on cows: "Use of Posilac has been associated with increases in cystic ovaries and disorders of the uterus during the treatment period." And: "Use of Posilac may result in increased digestive disorders such as indigestion, bloat, and diarrhea."
There is abundant evidence that, when cows get mastitis, farmers give them antibiotics. Mastitis (or the pus it puts into milk) is a major cause of lost revenues to dairy farmers. According to the U.S. General Accounting Office (GAO), FDA has approved use of 30 antibiotics on dairy cows but an additional 50 antibiotics are suspected of being used illegally on dairy cows. A 1988 Illinois survey found over 200 different animal drugs on dairy farms, 58% of them not approved for use on dairy cows. Furthermore, the routine tests that FDA applies to milk nationwide can only detect 4 types of antibiotics, so FDA is not in a position to protect consumers from illegal use of antibiotics (which are sold without prescription at farm supply stores). Antibiotic residues in milk --which seem certain to increase with rBGH use --may cause adverse allergic reactions in some consumers, and very likely will contribute to development of strains of bacteria that are resistant to antibiotics, thus reducing the effectiveness of antibiotic medicinals against human and animal diseases. [12]