Effects of replacing fishmeal protein by hemoglobin powder protein on growth performance, food intake, feeding-related gene expression and gut histology of hybrid grouper (Epinephelus fuscoguttatus x Epinephelus lanceolatus) juveniles

摘要

An 8-week growth trial was conducted to evaluate effects of replacing fishmeal protein (FMP) by hemoglobin powder protein (HPP) on growth performance, food intake, feeding-related genes expression and gut histology of hybrid grouper (Epinephelusfuscoguttatus x Epinepheluslanceolatus) juveniles. Seven isoenergetic (340 kcal per 100 g dry matter), isoproteic (53.5% of dry matter) and isolipidic (7.5% of dry matter) experimental diets were formulated to replace 0%, 15%, 30%, 45%, 60%, 75% and 90% FMP with HPP, being abbreviated as FMP, HPP15, HPP30, HPP45, HPP60, HPP75 and HPP90, respectively. Each experimental diet was fed to triplicate groups of 30 hybrid grouper juveniles (average initial body weight: 5.27 +/- 0.05 g/fish) which were stocked into small floating cages (L 120 cm x W 70 cm x H 50 cm). Experimental cages were labeled and located in seven connective 6-m(3) indoor concrete tanks (L 3m x W 2m x H 1 m) with 3 cages occurring in each tank. Fish were fed twice daily (08: 00 and 16: 00) to apparent satiation. Water quality was monitored daily.