ABSTRACT
A hog (pig) processor once claimed, “We use all parts of the ani mal except for the squeal.” In reality, in the animal-processing in dustry, an average of 4.5 kg (10 lb) of protein is lost to the sewer for every 454 kg (1,000 lb) of live weight kill (lwk). Some animal products, such as bone and blood, are grossly underutilized. Much of this lost and underutilized product can be recovered and/or up graded through in-plant pollution reduction techniques and wiser processing of animal by-products. The process changes necessary to accomplish these tasks can provide additional profit, save or upgrade valuable protein, and reduce pollution. If half of the pro tein now lost to the sewer were recovered, there would be at least an additional 181 million kg (400 million lb) of protein each year, worth perhaps $400 million (1987 dollars) from animal processing in the United States (Hansen, 1983).
