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Panel Gives Local Perspective on rBGH by Elizabeth Ferry Drinking milk is as American as apple pie. But the introduction of recombinant bovine growth hormone (rBGH) has raised questions in some consumers’ minds. How does rBGH work? Does the human body respond any differently to it than to non-rBGH milk? What effect does it have on the health of cows or on the local farm economy? On Tuesday, October 24, the Co-op’s Education Department presented "Bovine Growth Hormone: Information for Consumers" as the third and final event in its "Educated Eater: Know What You Eat" series. The Co-op’s goal was to present a multi-faceted panel that could speak to all sides of the issue. Speakers included two local farmers, a veterinarian, an endocrinologist, and a professor of consumer economics. The information that they shared challenged many assumptions and held several surprises. A summary of the evening’s discussion follows. What is Bovine Growth Hormone? Before one can understand recombinant bovine growth hormone, one first needs to understand the growth hormone that occurs naturally in all cows. Bovine growth hormone is produced in the cow’s pituitary gland. The level of the hormone increases as a pregnant cow gets ready to give birth, and remains high in the first few months after the calf’s birth. The growth hormone is passed on to the calf through its mother’s milk. The hormone also stimulates milk production in the mother and coordinates a variety of body mechanisms that help to maintain the animal’s metabolic and physiologic equilibrium. Recombinant bovine growth hormone is a synthetic form of the hormone. The word "recombinant" refers to the method of producing the hormone outside of the cow. The laboratory technique used to created rBGH involves splicing the gene that produces BGH in the cow into the genetic information of a bacterium. The bacterium then uses its own protein synthesis machinery to produce the hormone. Of the 190 amino acids that make up bovine growth hormone, the recombinant version differs by only one. The synthetic version is nearly identical to the original in structure, and it appears to be identical in how it functions in the cow’s system. Recombinant bovine growth hormone, also known as recombinant bovine somatotropin (rBST), is sold under the brand name Posilac. Posilac is produced by the Monsanto Corporation, a leader in the bio-tech industry. How Does it Work? Recombinant bovine growth hormone is used to increase milk production in lactating cows. This was explained in greater detail by Dan Kelly, large and small animal veterinarian from Bradford, Vermont. Dr. Kelly serves many of the dairy farms in this part of the Upper Valley. About half of his clients use rBGH. Dr. Kelly’s views are based both in his veterinary training and in his observations of many Upper Valley farms. rBGH is injected into a cow to increase both the rate and duration of lactation. Physiologically, it signals the cow’s liver to produce more insulin-like growth factor (IGF-1) which, in turn, has an impact on milk production. Dr. Kelly stressed that the IGF-1 stimulated by rBGH is identical to the IFG-1 that is produced by cows who are not injected with rBGH. Once a cow has calved, her milk production gradually increases over a 90-day period, whether her hormone level is supplemented or not. Milk production then gradually tapers off over a period of ten months. Farmers who use rBGH typically start treating a cow nine weeks into her lactation period. With rBGH, the curve stays about the same, but the peak goes up a little higher, and the curve is sustained longer. Farmers generally see an increase of 10 to 15 pounds of milk per day. While this does not seem like a lot, Kelly said that it "adds up tremendously" over the course of the lactation period. Does it Affect Humans? Dr. John Turco, endocrinologist at Dartmouth-Hitchcock Medical Center, raised questions without conclusive answers regarding the safety of consuming milk produced with rBGH. What happens to bovine growth hormone and IGF-1 when they enter the human system? The standard answer is that these peptides are destroyed in the human stomach and would not be absorbed by the body. "That may be true, but like everything else in science, it isn’t that simple," said Dr. Turco. A few scientific studies show that perhaps the growth hormone — but more likely the IGF-1 — is not totally destroyed by gastric acids. Further, some studies indicate that IGF-1 could stimulate cell growth and could lead to cancer. Neither side in this debate has information that is conclusive. More studies need to be conducted to amass more data. In the meantime, however, the majority of scientific literature currently available indicates that this is safe. The Food and Drug Administration has approved the safety of milk produced with rBGH. While Dr. Turco generally concurs with the product’s safety, "that doesn’t mean that science is infallible, or that everyone should accept" this conclusion. He cited an example of a drug approved by the FDA that was later withdrawn from use due to unforeseen effects in a segment of the population. "I wish that I could come down and say, in black and white, that it is safe, or it isn’t safe," he concluded, "but it isn’t that simple." Economic Survival of the Small Family Farm Farmers who raise our food have a special perspective on its production. For that reason, the panel included two Upper Valley farmers. Pat McNamara of McNamara Dairy in Plainfield, New Hampshire, does not use rBGH on his herd. Tom Debevoise of Upwey Farm in South Woodstock, Vermont, finds it a useful resource. Both are soft-spoken men who obviously care deeply about their farms, the animals, and the future of family farms in the region. Both farmers agree that rBGH can increase milk production and efficiency in a well-managed herd. Both said that it did not need to cause health problems in cows. They further agreed that only well-managed herds will benefit from the use of rBGH; it is not a substitute for good management practices. They differed in their approach to earning a living in the current farm economy. Dairy farmers today earn the same price for milk that they did in 1979. Since the introduction of rBGH in 1994, the United States has seen an increase in milk production despite a reduction in the number of farms. This has created a milk surplus which, in turn, has lowered the unit price paid to the farmer. Concern for the cows’ health made Tom Debevoise and his wife, Lori Livingston, cautious in their approach to rBGH. However, in the five years that they have been using it, they have not seen any negative effect on the animals’ health. The couple decided to use rBGH in response to the constant pressure to produce milk in greater quantity and with greater efficiency. Although rBGH increases costs and adds work to the daily routine, it is a useful management tool. "Given our location, we can’t expand the farm’s acreage or the size of our herd," Debevoise explained. "With rBGH, we can increase milk production and provide a living for the family from the same number of animals." Pat and Mary McNamara looked at what rBGH had to offer and chose a different route. The McNamaras process and bottle their own milk from their herd of 110 cows. Consumer preference played a large role in the McNamaras’ decision not to use rBGH. "We had decided not to use it long before it became a standard in the industry," Pat recalls. "When it was publicized in 1994, our phone was ringing off the hook. Our customers wanted to know if we were using it. They didn’t want it. It costs more to produce milk without rBGH. But we produce enough volume that, with bottling our own, we are okay without it." What Do Consumers Want? Dr. Jane Kolodinsky, professor of Community Development and Applied Economics at the University of Vermont, conducts research on the structure and institutions that impact the quality of life of rural people. Her research concludes that consumers: - want to be able to choose between rBGH and non-rBGH milk - want those products labeled - are willing to pay more for this type of information, in some cases. Currently, in Vermont, consumers are paying up to three dollars more per gallon for rBGH-free milk. However, most of this premium is consumed by middlemen; very little of it goes to the farmer. Kolodinsky reports that it remains to be seen whether rBGH or rBGH-free producers will be the winner in the marketplace. Conclusion The most surprising information had to do with the economic pressures on small dairy farmers. It is difficult to be a small producer in a market that is characterized by a surplus of milk from large farms. rBGH plays a complex role on this stage: it has helped to create this difficult economic situation and yet, for some farmers, it offers some financial relief as well. rBGH was supposed to keep milk prices affordable for the consumer; to the contrary, consumer prices have risen. At the same time, rBGH has resulted in a lower price per unit for the farmer, but has increased profits for the life sciences company that makes it. The evening was a rare opportunity for farmers, consumers, and health professionals to meet and grapple with issues that affect every one of us. Each presenter spoke from his or her direct experience in the field, always respecting other points of view and often challenging listeners to think beyond the limits of their previous understanding.