Study seeking reasons for milk-fat difference

Cornell University researchers know that Northern New York dairy farms have slightly lower percentages of milk fat and milk protein in the milk they produce than farms from other regions of the state.

They're trying to find out why.

So far, Larry E. Chase, professor of animal science at Cornell University, Ithaca, has analyzed data from 52 dairy farms in Clinton, Essex, Franklin, Jefferson, Lewis and St. Lawrence counties.

He found that the factors of larger corn silage particle size and higher neutral detergent fiber for digestibility correlate with higher levels of milk fat and higher ration starch level correlates with higher milk protein levels.

"The longer particle may be a more normal ruminant environment," Mr. Chase said. "The higher starch level may provide more energy for microorganisms and in the intestine."

But Mr. Chase said a cause-effect relationship is not yet clear. He will next consider multiple factors compared to protein and fat content.

"Dairy farmers are paid on how many pounds of fat and protein are in the milk, not on the volume of milk," said Ronald A. Kuck, dairy and livestock educator for Cornell Cooperative Extension of Jefferson County.

So having less fat and protein in the milk means less money for the dairy farm.

"The end goal would be to help identify whether their management practices could be improved," said Frans J. Vokey, dairy management educator in Lewis County. "Farmers can use the information to elevate the milk components in their milk."

Teams from the university and Cornell Cooperative Extension collected samples of feed and water, herd and production records and data on the size and condition of cows.

"It was really anything that might affect the cows," Mr. Kuck said.

The herds involved in the study ranged from those with 30 cows to those with over 1,000. They all used the total mix ration method of feeding, in which different feeds go into a mixer together so there is consistency in every bite.

Most farms were visited twice during the spring. The Northern New York Agricultural Development Program supported the research.

With additional funding from the university, Mr. Chase will use the same process to examine component levels in other regions in a three-year study. Results are expected at the beginning of next fall.

"A comparison of Northern New York versus other regions is important," Mr. Chase said. "We can see if we got similar answers or different answers for the important variables."