Effects of dietary supplements on growth performance and phosphorus waste production of Australian catfish, Tandanus tandanus, fed with diets containing Canola meal as fishmeal replacement

Abstract

Effects of dietary phytase, amino acid (AA), and inorganic phosphorus (P) in canola meal diets on the growth and P waste production of Australian catfsh, Tandanus tandanus were evaluated. Fishmeal protein was replaced by 30% and 45% with canola meal protein in two separate experiments, in which test diets were fortifed with phytase, AA, inorganic P, or their combinations. Addition of sole phytase to the 30% replacement diets did improve growth performance and feed utilization of fsh compared to those fed with the non-phytase diet. Inclusion of phytase and/ or AAs did not improve the growth and feed utilization of catfsh when fshmeal protein was replaced by 45% while adding inorganic P showed signifcant improvement in the performance of the fsh. Ortho-P waste was signifcantly lower while total P waste was signifcantly higher in fsh fed with canola meal diets at both levels of fshmeal replacement. Phytase did not affect the total P waste of catfsh but a combination of phytase and AA resulted in a signifcant reduction. Dietary inclusion of inorganic P signifcantly elevated the total P waste of catfsh compared to that of the control fsh. It was concluded that the use of canola meal in combination with inorganic P in diets for Australian catfsh could signifcantly increase nutrient pollution in aquaculture. © 2011 Huynh HPV, et al.