MILK PRODUCTION IS A MAJOR DETERMINANT OF DAIRY FARM PROFITABILITY. GREATER MILK PRODUCTION INCREASES NUTRIENT EFFICIENCY, AND INCREASED NUTRIENT EFFICIENCY REDUCES ENVIRONMENTAL IMPACT. MILKING FREQUENCY IS THE NUMBER OF TIMES A COW IS MILKED IN A DAY. INCREASING MILKING FREQUENCY, THAT IS MILKING COWS MORE TIMES IN A DAY, INCREASES A COW'S MILK PRODUCTION. RECENT EXPERIMENTS HAVE SHOWN THAT INCREASING MILKING FREQUENCY ONLY DURING THE FIRST WEEKS OF A COW'S LACTATION CAN INCREASE MILK PRODUCTION THROUGHOUT LACTATION EVEN AFTER A SUBSEQUENT REDUCTION IN THE NUMBER OF MILKINGS PER DAY.OUR LONG-TERM GOAL IS TO FURTHER INCREASE MILK PRODUCTION RESULTING FROM INCREASED MILKING FREQUENCY IN EARLY LACTATION. THIS PROJECT WILL DEVELOP METHODS THAT DAIRY FARMERS CAN USE TO INCREASE MILK PRODUCTION BY INCREASING MILKING FREQUENCY ONLY DURING THE EARLY PORTION OF A COW'S LACTATION.OUR FIRST OBJECTIVE IS TO REFINE THIS METHOD TO MAXIMIZE GAINS IN MILK YIELD RESULTING FROM INCREASED MILKING FREQUENCY. OUR SECOND OBJECTIVE IS TO DETERMINE HOW MILKING FREQUENCY INFLUENCES THE MILK PRODUCING CELLS OF A COW.WE EXPECT THAT OUR FOUR EXPERIMENTS FOR OBJECTIVE 1 WILL RESULT IN A SPECIFIC APPROACH DAIRY FARMERS CAN USE ON THEIR FARM THAT GIVES THEM THE GREATEST MILK YIELD GAIN WHEN THEY INCREASE THE MILKING FREQUENCY OF THEIR COWS IN EARLY LACTATION WHILE BALANCING LABOR NEEDS TO SUPPORT EXTRA MILKINGS. FOR THE SECOND OBJECTIVE, WE EXPECT TO IDENTIFY SPECIFIC PROTEINS IN THE MILK PRODUCING CELLS OF DAIRY COWS THAT RESPOND TO CHANGES IN MILKING FREQUENCY.A MAJOR IMPACT OF THIS PROJECT WILL BE THE USE OF THE FINDINGS BY DAIRY FARMERS TO INCREASE MILK PRODUCTION, INCREASE EFFICIENCY, AND IMPROVE FARM PROFITABILITY. FARMERS WILL BE ABLE TO TAKE THE COMBINATION OF METHODS DEVELOPED FROM THIS PROJECT AND BEGIN TO APPLY THEM TO THEIR OWN COWS TO INCREASE MILK PRODUCTION. AN ADDITIONAL IMPACT WILL BE THE IDENTIFICATION OF THE PROTEIN OR PROTEINS THAT RESPOND TO CHANGES IN MILKING FREQUENCY. MILKING FREQUENCY IS KNOWN TO DIRECTLY AND IMMEDIATELY IMPACT MILK PRODUCTION, BUT HOW THE MILK PRODUCING CELLS OF THE COW DETECT THESE CHANGES AND RESPOND IS NOT UNDERSTOOD. IDENTIFYING THESE PROTEINS MIGHT ENABLE SCIENTISTS TO IDENTIFY COWS MORE OR LESS RESPONSIVE TO MILKING FREQUENCY ALLOWING FARMERS TO SELECT FOR COWS THAT HAVE THE GREATEST POTENTIAL TO PRODUCE MILK.