The major point of conflict is over whether the definition of milk should be expanded to include ultra-filtered milk, or milk protein concentrates, used in all kinds of new products including low-carbohydrate beverages, drinkable yogurt and even energy drinks.
A national public hearing last week gave both sides the chance to air their views, and opposed has been vociferous.
"Dairy farmers have worked to develop an identity of milk and dairy products as pure and wholesome in the eye of the American consumer," said Dave Frederickson, National Farmers Union (NFU) president in a recent editorial.
"The change would seriously compromise decades of work and investment by the nation's dairy farmers and quality cheese makers and would be a serious deception to our nation's consumers."
In addition, the burden of proof lies at the door of those demanding change, and many in the industry remain unconvinced.
"MIF (Milk Industry Foundation) believes that the proponents of such amendments carry the burden of coming forth with solid data and analysis demonstrating both the need for a change and that the proposed amendment will address that need," said IDFA (International Dairy Foods Association) chief economist Bob Yonkers in testimony.
"Anecdotal evidence or broad suppositions do not suffice."
But despite these objections, there is increasing pressure for change. Many major milk producers remain frustrated that makers of novel products incorporating milk derivatives do not have to follow the same rules as milk sellers.
Milk sales have been plummeting for decades. In fact, since milk consumption peaked at 45 gallons per person in 1945, it has steadily declined, hitting a record low of 23 gallons per person in 2001, according to the USDA.
On the other hand, demand for new beverages that contain traces of milk has soared. Milk protein concentrates are increasingly popular with manufacturers because of their versatility and relatively low cost.
The problem is that dairy farmers in the US receive the highest prices when their raw milk ends up in milk bottles as opposed to cheese, yogurt, butter or any other dairy product. A broader definition of milk would therefore translate into higher prices if raw milk finishes up in products that compete with milk on the supermarket shelf.
However, there is real fear that consumer confidence in a product generally accepted to be healthy and nutritious could be severely damaged if the definition change is pushed through. Despite growing concern over the presence of fat in food products, fresh milk continues to enjoy a wholesome reputation.
"It seems unimaginable that any serious consideration would be given to tampering with the definition of a product with such an overwhelmingly positive perception," said Joe Logan, president of www.ohfarmersunion.org Ohio Farmers Union, who gave testimony to the hearing.
Logan points to a 2001 General Accounting Office report on ultra-filtered milk, which claimed that separation by filtration results in a highly concentrated ultra-filtered milk that is not nutritionally equivalent to fluid milk.
The study also cited that most of the vitamins, minerals, enzymes, and lactose are removed through the filtration process.
"Milk with the nutrients removed?" said Logan. "The current definition of milk already allows great latitude for processors to supplement or remove many dairy derivatives from milk products.
"Any further broadening of the definitions or interpretations only serves to signal the industry that any fractionation or recombination of dairy derived ingredients can pass as milk."
USDA officials, who have been reviewing this issue since August 2003, will now review the testimony before making a ruling, which could take six months or more. Even if the proposal is approved, it would not change what products could be labeled as milk at the grocery store; it would only affect how dairy products are priced.