During this century three major trends have characterized the development of the hog slaughter-processing industry in Iowa and in other parts of the nation: Slaughter plants have moved from terminal market locations to hog production areas, new firms have entered the slaughter-processing industry reducing the relative importance of the once dominant big five meat packing firms, and muitispecies slaughtering plants have been replaced by plants specializing in the slaughter of a single species of livestock..
