Washington lobbyist C. Donald Van Houweling and the National Pork Producers Council that he represents have spent a good part of the last four years battling the U.S. Department of Agriculture over a number of labeling and food safety regulations.

Van Houweling fought to head off regulations that would have banned the use of nitrites in bacon, and his pork producers organization is involved in two lawsuits against department regulations.

Now, in an abrupt change of roles, Van Houweling is no longer the combative outsider but a USDA insider who is directing the transition for President-elect Ronald Reagan in the agencies whose rules and regulations he had been fighting.

Van Houweling's activities at the USDA provide a glimpse of the conflicts and counterconflicts that are sure to take shape once a Reagan administration committed to lightening the burden of federal regulation takes office. As Reagan's administration seeks to roll back regulation, some say, it is natural that he will call on those with expertise in the regulated fields.

In his new role of unpaid member of the Reagan transition team, Van Houweling has cut a wide swath -- and he has also run into some early opposition to bureaucratic change.

Outgoing Carter administration officials complain that in some parts of the bureaucracy special interests have begun to press for changes even before the new administration has been sworn in, thereby putting career officials in the awkward position of serving two masters.

Van Houweling acknowledged in a weekend interview that he had requested that career officials provide to him by today option papers on a range of regulatory matters before the USDA's Food Quality and Safety Service. Carol Tucker Foreman, the assistant secretary for food and consumer affairs, said she had directed the agency "not to give them any option papers."

Foreman said she understood that one of the requested option papers involved a suit over the Department of Agriculture's 1977 rules for the curing of pork carrying the label "country ham." A federal court in Tennessee recently struck down the rules and a decision on whether to appeal is pending.

"The decision on how we proceed will be made by the general counsel's office, the Justice Department and myself. When the decision is made we'll tell them about it," said Foreman.

Van Houweling denied one report that he already had sought assurances from the USDA's Food and Nutrition Service that it would delay issuing revised guidelines, long opposed by the U.S. meat industry, for school luncheon menus.

"I can specifically say that I didn't discuss those guidelines with anybody in the Food and Nutrition Service," he said. Van Houweling acknowledged, however, that the pork producers and the meat industry publicly opposed the guidelines because they "were part of a general trend that says if you can get protein without livestock products, that's preferable."

Van Houweling also said that he had dropped the idea of trying to get into the Carter administration's budget some additional money to combat the livestock disease bersolosis, after being advised by a Reagan transition leader at the Office of Management and Budget that it would be inappropriate.

"I'm not mixing the two jobs," said Van Houweling. "I've said that I'm not going to talk about pork council business when I'm working on the transition. Of course we have expressed our opinion about a lot of things. But it would be hard to find anybody who hasn't expressed an opinion about Fsqs [Food Safety and Quality Service] or Aphis [Animal and Plant Health Inspection Service]."

Van Houweling, a veterinarian who directed the Food and Drug Administration's Bureau of Veterinary Medicine in the Johnson administration, feels "there has been too much regulation in this last administration."

"I would suspect that the new administration will put in people who won't take the same view as Carol Foreman and her crew," he added.

Van Houweling's boss in the transition is Richard Lyng, president of the American Meat Institute here and an opponent of some of the regulations put in during the Carter administration. The AMI recently wrote Foreman urging the dropping of rules prohibiting the use of equipment containing PCB chemicals in food processing plants. Both AMI and the National Pork Producers Council are suing the Department of Agriculture to prevent the labeling of turkey meat as "turkey ham."

In addition to the pork producers' suit against the USDA over the labeling of "turkey ham," the organization is also in litigation over a regulation, published in August 1979, that would permit meats not preserved with nitrites to be marketed under "traditional" names such as frankfurters as long as their labels carried instructions about proper handling.

A federal appeals court in St. Louis has reversed a lower court ruling and upheld the USDA's regulation.

The pork industry was the subject of a major regulatory controversy during the Carter administration -- the debate over the safety of nitrites used by meat packers to preserve bacon.

Van Houweling charged that the uncertainty over the safety of nitrites had cost the pork industry between $1 billion and $1.5 billion in lost sales. However, officials at USDA and the Food and Drug Administration say there is still concern over possible genetic effects and over the fact that nitrites can produce cancer-causing derivatives such as nitrosamines during cooking or in the body after the foods are eaten.

Foreman said she believed that a major accomplishment of the Carter administration had been improved monitoring of food for chemical residues since she took over as the top consumer protector at the USDA.

"I'm fearful that the industry is anxious to dismantle the residue detection apparatus that we've built up," she said.