Effects of replacing fishmeal protein with poultry by-product meal protein and soybean meal protein on growth, feed intake, feed utilization, gut and liver histology of hybrid grouper (Epinephelus fuscoguttatus female x Epinephelus lanceolatus male) juveniles

摘要

Two consecutive eight-week growth trials were undertaken to evaluate the effects of replacing fishmeal protein (FMP) with poultry by-product meal protein (PBMP) and soybean meal protein (SBMP) on growth, feed intake, feed utilization, gut and liver histology of hybrid grouper (Epinephelus fuscoguttatus female x Epinephelus lanceolatus male) juveniles. In trial 1, eight isoenergetic (340 kcal per 100 g dry matter) and isoproteic (53.5% of dry matter) experimental diets were formulated to replace 0%, 10%, 20%, 30%, 40%, 50%, 60% and 70% FMP with PBMP, being abbreviated as FMP, PBMP10, PBMP20, PBMP30, PBMP40, PBMP50, PBMP60 and PBMP70, respectively. Based on the results of trial 1, another six isoenergetic (340 kcal per 100 g dry matter) and isoproteic (53.5% of dry matter) experimental diets including a high FM (86.64%) diet (FMP) and five low-FM (25.99%) diets were formulated in trial 2, and in the low-FM diets, 0%, 7%, 14%, 21% and 21% PBMP was replaced with SBMP, being abbreviated as PBMP, SBMP7, SBMP14, SBMP21, SBMP28, respectively. The initial average body weights of experimental fish were 6.0 +/- 0.05 g in trial 1 and 6.8 +/- 0.08 g in trial 2 (means +/- S.D.), and fish were fed their described diets by hand to apparent satiation twice daily (08:00 and 16:30) at a density of 30 fish/cage (trial 1) or 15 fish/cage (trial 2). Experimental cages were labeled and located in connective 6-m3 indoor concrete tanks (L 3 m x W 2 m x H 1 m) with 3 cages occurring in each tank. Each treatment had three replicates both in trial 1 and in trial 2.