Replacement of fish meal in diets for Australian silver perch, Bidyanus bidyanus: III. Digestibility and growth using meat meal products

Abstract

Apparent digestibility and availability coefficients for beef and bone meal, lamb and bone meal, a high protein meal from mixed species (mixed meat meal, reduced ash, no bones) and from Provine®, a high protein meal based on selected ingredients, were determined for juvenile silver perch. Experimental diets comprised a reference diet plus meat meal products at either 15% or 30% inclusion. Silver perch readily accepted diets with up to 30% meat meal. Digestibility coefficients for dry matter, energy, protein, and availability coefficients for amino acids were determined to assist with the formulation of diets to assess growth of silver perch. Digestibility coefficients for dry matter, energy, and protein all increased with increasing protein content in the meat products. Average amino acid availability coefficients were highest for the mixed meat meal and Provine®. Availability coefficients for alanine, arginine, glycine, methionine, proline and serine were all significantly higher for these products than for either beef or lamb meal. Availability of sulphur amino acids was significantly lower in Provine® than in other products. Compared with fish meal, all meat products contained less lysine and some meat products were also low in phenylalanine, isoleucine, and histidine. An increase in total protein content, through removal of bone, improved the nutritional value of meat meal in silver perch diets. Juvenile silver perch were grown for 65 days in 10 000-l tanks, using one of five diets with similar digestible nitrogen, energy, and dry matter but different contents of fish meal, lamb meal, and Provine®. Fish growth was reduced when diets contained less than 13% fish meal and more than 9% Provine®. However, feed conversion efficiency and protein retention efficiency (PRE) were unaffected by diet formulation. These results indicate that meat meal can replace most of the fish meal in silver perch diets without reducing fish performance.