and thus at less overall cost to dairy farmers - is the goal of a biotechnology project at Utah State University.
Robert C. Lamb, head of the school's department of animal, dairy and veterinary sciences, is heading a project studying the effects of bovine somatotropin, a genetically engineered growth hormone.Lamb said the idea of using the hormone was first conceived in the 1930's and was given considerable study in Great Britain during World War II. But at that time it was found to be counterproductive because the scientists had to use natural hormones from cattle. The process was time-consuming and costly.
But with the advent of biotechnology, also called genetic engineering, scientists have found a way to synthetically produce large quantities of the somatropin. That capability has given rebirth to the idea of increasing milk production while reducing the number of animals needed.
Lamb said one goal is to help small farms become more profitable while helping control the surplus numbers of dairy cattle in the United States.
At USU, researchers are working with four pharmaceutical companies to complete testing on the hormone while the U.S. Food and Drug Administration considers whether to approve the product for general use. Lamb said the arrangement is unusual because the four companies are competing for approval of their specific genetically altered strain. He said they are cooperating in the testing to get the information to the FDA as soon as possible.
The bovine somatropin is one of the first genetically altered products that may have a commercial application in the animal field, Lamb said.
Lamb said the product has passed the first stage of approval, an FDA ruling saying the synthetic hormones pose no health threat in milk and meat products. Since the hormone is naturally secreted by the animal, traces are already in milk and meat. Part of the USU study has been to determine whether the added injections of the hormone increase those levels. Studies thus far have shown no significant increase.
Because the hormone involves a natural protein, it is easily digested and broken down. Lamb said this is why it must be injected to give the animal a large enough dose to produce the increased growth and milk production.
It appears there are no growth side-effects that will affect human consumers. Lamb said the hormone works only on cattle and therefore is safe for human consumption.
Current studies are focusing on the impact the product has on the animal itself. He said the FDA wants to be sure that the product does not threaten the health of the animal.
Some 200 cattle have been involved with the study for more than two years. Lamb said results show farmers using the hormone can increase milk production by 15 to 20 percent while only increasing feed by 5 percent. Lamb said part of the study is intended to determine if this ratio provides an economic incentive to use the product.
The study has found one negative effect. Use of the hormone does affect reproductive fertility of the animals. Lamb said part of the research is now focusing on whether that problem can be resolved by waiting longer before putting cows on the hormone. He said the effect is not alarming because the same phenomenon has been seen in cattle with naturally high milk production.
In addition to the USU herd, three local farms have been involved with research, all with results similar to the USU herd. The milk from the test herds is being purchased by a processing company for use in dairy products such as cheese and yogurt. None is being marketed as bottled milk.
Lamb said researchers hope to have final FDA approval within five years.