|Rawles, Steven - Steve|
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 8/30/2007
Publication Date: 2/9/2008
Citation: Metts, L.S., Thompson, K.R., Rawles, S.D., Gannam, A.L., Webster, C.D. 2008. Apparent digestibility coefficients for dry matter, protein, lipid, and organic matter using various animal and plant protein sources by sunshine bass Morone chrysops X Morone saxatilis [abstract]. Book of Abstracts Aquaculture America. p. 240.
Technical Abstract: Limited information is available on the digestibility of nutrients in various practical ingredients used in diets for commercially-important finfish species. This information is especially needed for sunshine bass, Morone chrysops X M. saxatilis, to improve least-cost diet formulations and to allow effective substitution of feedstuffs. A study was conducted with large, market-size (867 g) sunshine bass to determine the apparent digestibility coefficients (ADCs) for moisture, protein, lipid, and organic matter in a variety of ingredients in floating, extrusion-processed, diets. The practical ingredients tested were menhaden fish meal (MEN), anchovy fish meal (ANCH), pet-food grade poultry by-product meal (PBM-pet), feed-grade poultry by-product meal (PBM-feed), dehulled soybean meal (SBM), and distiller’s dried grains with solubles (DDGS). Test diets consisted of a 70:30 mixture of reference diet to test ingredient with chromic oxide (1.0%) as the inert marker. Reference and test diet ingredients were mixed and extruded on a Wenger X85 single-screw extruder to produce floating pellets. The digestibility trials were conducted in twelve 1200-L circular tanks. Diets were randomly assigned to tanks of 30 sunshine bass and were fed once daily to satiation. Protein digestibility coefficients were significantly (P < 0.05) different among test ingredients and ranged from 86% for MEN to 65% for DDGS. Lipid ADCs were significantly different (P < 0.05) among test ingredients and ranged from 92% for MEN to 57% for SBM. Organic matter ADCs were significantly different (P < 0.05) among test ingredients and ranged from (90% for MEN to 17% for DDGS. This information will assist in the formulation of more efficient, economical diets for sunshine bass.