Agriculture Secretary-designate Clayton K. Yeutter, warmly praised by senators at his confirmation hearing, made clear that he will push for a major overhaul of farm subsidy programs. But proposed changes must await the outcome of the Uruguay round of trade talks, the former U.S. trade representative told the Senate Agriculture Committee. Senators lauded Yeutter for helping to increase exports of beef, citrus and processed food to Japan and tobacco to several Asian countries. In another Cabinet development, White House spokesman Marlin Fitzwater acknowledged that Louis W. Sullivan, President Bush's choice to be secretary of the Department of Health and Human Services, has asked whether he would be able to retain, possibly with pay, a relationship with Morehouse School of Medicine, of which he is president. "It is being considered," Fitzwater said.