Dairy Farm Resiliency Act This bill updates the Dairy Margin Coverage (DMC) program.As background, the DMC program was enacted in the 2018 farm bill to support dairy operations by allowing producers to buy a guaranteed margin for their milk production. The margin is the difference between the Department of Agriculture's (USDA's) national all milk price and a calculated feed cost, which provides producers optional risk protection on price and feed costs.The bill updates the current requirements that a participating dairy producer have an established milk production history with USDA's Farm Service Agency. Specifically, the bill requires that a dairy operation's production history for DMC be based on the most recent three-year history and be recalculated every five years.The bill also increases Tier I margin coverage for annual milk production to 6 million pounds or less (currently 5 million pounds or less) and Tier II margin coverage to over 6 million pounds (currently over 5 million pounds).