Growth, nutrient utilization and parameters of mineral metabolism in Nile tilapia Oreochromis niloticus (Linnaeus, 1758) fed plant‐based diets with graded levels of microbial phytase

Abstract

Diets with graded levels of the experimental microbial phytase SP1002 (0, 500, 1000, 2000 and 4000 FTU/kg) were fed to juvenile Nile tilapia (average BW = 68.8 g) for 60 days (n = 4). A digestibility trial ran parallel to the growth trial using 0.3 g TiO2/100 g as an indigestible marker. The efficiency of phytase supplementation was evaluated by parameters of growth response, crude protein and mineral utilization (using body composition data), apparent nutrient digestibility, mineral content in scale and vertebra and inorganic phosphorus in blood plasma. Data were submitted to ANOVA and Tukey-test using SAS-program. Significant improvements (p < 0.01) were found for growth, FCR and SGR, mainly for diets with 1000 and 2000 FTU/kg phytase supplementation. Protein utilization was significantly increased and maximized between 1000 and 2000 FTU/kg. Phosphorus utilization increased significantly up to 4000 FTU/kg. Digestibility of protein and phosphorus was also significantly improved. Phosphorus concentration in the blood, vertebra and scale increased significantly after phytase addition. Similarly, calcium and magnesium concentration in vertebra and scale were increased. Generally, phytase supplementation between 1000 and 2000 FTU/kg resulted in growth rates and mineralization parameters similar to a control diet with inorganic phosphorus.

Use of phytase at graded levels for improving nutrient digestibility, growth and hematology of Catla catla fingerlings fed Moringa oleifera seed meal (MOSM) based diet

“…On the other hand, 750 FTU kg -1 level was suggested as the most suitable level of supplementation for higher fat digestibility in L. rohita fingerlings (Baruah et al, 2007b). Higher EE digestibility was found in Nile tilapia when fed on 1000 and 2000 FTU kg -1 of phytase supplemented diets (Portz and Liebert, 2004). Hydrolysis of chelated phytic acid resulted in lower EE excretion in faeces that ultimately showed higher utilisation of EE by fish fingerlings resulting in higher digestibility (Hussain et al, 2014;2015a,b).…”

Effects of β-xylanase and 6-phytase on digestibility, trace mineral utilisation and growth in juvenile red tilapia,Oreochromis niloticus(Linnaeus, 1758)x O. mossambicus(Peters, 1852), fed declining fishmeal diets

“…Phytate has a high affinity to complex with Ca ions (Portz and Liebert, ). Carcass Ca levels were higher in diets containing phytase (and xylanase) compared to the controls, except for fish fed the 5% FM diets.…”

Availability of Dietary Zinc Sources and Effects on Performance of Pacific White Shrimp <i>Litopenaeus vannamei</i>(Boone)

“…Phytic acid has a strong affinity for zinc and other divalent minerals which results in their being unavailable to aquatic and terrestrial animals (Cheryan, 1980;Davis et al, 1993;Davis and Gatlin, 1996;Richards et al, 2010). Phytic acid has been observed to depress growth and also lower the availability of macro minerals and trace minerals in fish and shrimp (Spinelli et al, 1983;Richardson et al, 1985;Civera and Guillaume, 1989;Paripatananont and Lovell, 1995a;Usmani and Jaffri, 2002;Portz and Liebert, 2003;Helland et al, 2006;Laining et al, 2010). In the Pacific white shrimp L. vannamei, addition of phytic acid to diets did not significantly depress growth but it affected hepatopancreas zinc concentrations (Davis et al, 1993).…”