PHILADELPHIA (AP) _ A Bucks County meatpacking company has been charged with using chicken and pork byproducts in 165,000 pounds of meat products labeled ''all beef.''

The U.S. Attorney's office on Tuesday charged the C.D. Moyer company of Silverdale and one of its officers, Matthew A. Giuffrida, with mail fraud and selling adulterated meat products.

Moyer is a subsidiary of Freda Corp. of Philadelphia. Giuffrida, a secretary and director of Moyer and Freda, had held discussions with prosecutors and would plead guilty, according to his attorney, J. Clayton Undercofler III.

The prosecutors said the company used ''comminuted chicken meat,'' an emulsified mixture that can include 1 percent bone, and ''pre-blended pork'' in the ''all-beef'' products from February 1984 through March 1987.