The U.S. Agriculture Department wants to improve its handling of the nation's worst-ever outbreak of bird flu in poultry after coming under criticism for a slow and confusing response. The USDA is aiming to assign one person to communicate with each infected farm during the entire time the facility is affected by the deadly virus, John Clifford, the chief U.S. veterinary officer, said at a U.S. Senate Agriculture Committee hearing. Currently, a USDA representative deals with an infected farm for a period of about three to four weeks as part of a rotation, Clifford told lawmakers. Having one dedicated liaison to answer farmers' questions "would make their lives a lot simpler and easier," he said. The agency also plans to embed a federal worker in every contract crew to oversee the work responding to the virus, Clifford said. Since December, the bird flu has killed more than 48 million chickens and turkeys nationwide. Most of the losses have been egg-laying hens in Iowa, the nation's top egg-producing state. The USDA has already taken steps to better respond to the outbreak and has caught up on culling infected birds after initial delays, Clifford said. Such delays can increase the risk for the disease to spread. U.S. Senator Joni Ernst, a Republican of Iowa, said farmers complained that the process of gaining USDA approval to cull birds at infected farms, receive government compensation for the losses and restock barns with new birds "has really been very complicated." "It's been so frustrating" for farmers, she said. "It's been very slow." In Iowa, there was "mass confusion" about the government response, said Brad Moline, an Iowa turkey farmer and representative of the National Turkey Federation. The USDA and state governments should have developed a better game plan, he said at the hearing. Recently, the number of new infections has slowed because warmer weather makes it harder for the virus to survive. However, the USDA is worried about a possible resurgence in the fall, as wild birds that spread the virus will likely carry it when they begin migrating south. The agency wants to stockpile vaccines for poultry ahead of autumn but has not decided whether to use them, Clifford said. The USDA will first assess the impact on international trade. "I want the tool in the tool box to use if we need it," Clifford said about the vaccine.