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 catfish, 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 fortified 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 fish compared to those fed with the non-phytase diet. Inclusion of phytase and/ or AAs did not improve the growth and feed utilization of catfish when fishmeal protein was replaced by 45% while adding inorganic P showed significant improvement in the performance of the fish. Ortho-P waste was significantly lower while total P waste was significantly higher in fish fed with canola meal diets at both levels of fishmeal replacement. Phytase did not affect the total P waste of catfish but a combination of phytase and AA resulted in a significant reduction. Dietary inclusion of inorganic P significantly elevated the total P waste of catfish compared to that of the control fish. It was concluded that the use of canola meal in combination with inorganic P in diets for Australian catfish could significantly increase nutrient pollution in aquaculture

Effect of Microbial Phytase on Nutrient Availability and Growth of Juvenile Clarias gariepinus Fed Soyabean and Groundnut-based Diets

“…The positive effects of phytase on amino acid availability have been observed in several animal studies in low phosphorus and amino acid-deficient diets [6,7,11,12,13,14]. Huynh and Nugegoda [15] reported that inclusion of phytase and/ or amino acids did not improve amino acid profile of canola meal diet supplemented with limiting amino acid in Australian catfish (Tandanus tandanus), which showed no improvement in growth of the fish. Similarly, supplementation of phytase in amino acid-adequate diet of young chicks fed diet based on groundnut cake had no effect on growth [12].…”