** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** IMPROVING THE EFFICIENCY OF NUTRIENT CONVERSION TO MILK IN DAIRY COWS CAN BE ACHIEVED BY INCREASING MILK PRODUCTION. MILK IS PRODUCED BY CELLS IN THE MAMMARY GLANDS OF DAIRY COWS. THIS PROJECT INVESTIGATES THE LOSSES OF CELLS FROM THE MAMMARY GLAND INTO MILK. MAINTAINING CELLS IN THE MAMMARY GLAND HAS THE POTENTIAL TO INCREASE MILK PRODUCTION AND THE PRODUCTIVE LIFE OF DAIRY COWS. IMPROVING PRODUCTION EFFICIENCY AND THE PRODUCTIVE LIFE OF DAIRY COWS INCREASES THE PROFITABILITY OF DAIRY FARMERS, PROLONGS THE LIFE OF DAIRY COWS, AND REDUCING THE ENVIRONMENTAL IMPACT OF DAIRY COWS.WE HYPOTHESIZE THAT CELLS LOST INTO MILK LEAD TO REDUCTIONS IN MILK PRODUCTION BY DAIRY COWS AND THAT UNDERSTANDING HOW AND WHY CELLS END UP IN MILK WILL GIVE US TOOLS TO REDUCE THESE LOSSES AND INCREASE MILK PRODUCTION. OUR AIMS INCLUDE (1) DESCRIBING THE CELLS THAT ARE FOUND IN MILK AND COMPARING THEM TO CELLS REMAINING IN THE MAMAMRY GLAND AND (2) DESCRIBING WAYS THAT PEOPLE MANAGING DAIRY COWS OR THEIR LIVING CONDITIONS INFLUENCE THE NUMBERS OF CELLS FOUND IN MILK.WE EXPECT THAT THE CELLS FOUND IN MILK ARE DISTINCT FROM THOSE OF THE MAMMARY GLAND, BUT THAT THE CHARACTERISTICS AND QUALITIES OF SOME CELLS WILL REVEAL THAT THEY COULD HAVE REMAINED IN THE MAMMARY GLAND, THAT THEY WERE PREMATURELY LOST WHILE STILL PRODUCTIVE. WE EXPECT THESE PREMATURELY LOST CELLS TO BE LOST IN GREATER AND LESSER AMOUNTS WHEN COWS ARE MANAGED FOR DECREASED AND INCREASED MILK YIELD. WE BELIEVE THIS IS A FORM OF REGULATION THE COW AND MAMMARY GLAND EMPLOY TO RIGHT-SIZE THE NUMBER OF CELLS IN THE MAMMARY GLAND TO RESPOND TO CONDITIONS OF THE COW.OUR GOAL IS TO EXTEND LACTATION LENGTH AND MAINTAIN MILK PRODUCTION IN DAIRY COWS BEYOND TRADITIONAL LENGTHS. THE IMPACT OF ACHIEVING THIS WOULD BE INCREASED PROFITABILITY OF DAIRY FARMERS AND IMPROVED PRODUCTIVE LIFE OF DAIRY COWS. DAIRY FARMERS EARN INCOME FROM SELLING MILK AND MAINTAING MAXIMAL MILK PRODUCTION FROM DAIRY COWS. THIS RESULTS IN THE STRONGEST MARGINS FORPROFITABILITY BY MAXIMIZING MILK YIELD PER UNIT OF FEED INPUT. COWS ARE OFTEN CULLED FROM DAIRY HERDS FOR LOW MILK PRODUCTION. MAINTAINING HIGHER LEVELS OF MILK PRODUCTION FOR GREATER LENGTHS OF TIME INCREASES THE PRODUCTIVE LIFE OF DAIRY COWS AND REDUCES THE LIKELIHOOD THAT THEY WILL BE REMOVED FROM THE HERD SOONER.