Composition, preservation, and use of sea clam viscera as a protein supplement for growing pigs

Use of surf clam viscera as an animal feed was assessed by measuring nutrient content, susceptibility to spoilage, preservation with organic acid, and replacement value for soybean meal when fed to growing pigs. Viscera exiting the processing plant averaged 88% moisture and 71% CP in DM. Amino acid contents (51% in DM) and profiles were similar to those of soybean meal. Storage and feeding quality of wet viscera could be maintained up to 3 wk by adding formic or propionic acid (3.5%, wt/wt). Pigs readily ate corn-based diets containing wet viscera preserved with propionic acid. Growth rate was similar for pigs from 18 kg to market weight (92 kg) when soybean meal and(or) clam viscera were fed as protein supplements. However, cooked loin roasts from pigs fed one-half or all supplemental protein from viscera (5 or 10% viscera in diet DM) had distinctive fishy aromas. To produce acceptable pork, future studies must identify lower dietary levels or withdrawal periods for viscera.