Effect of yeast-fermentation of canola meal on nutrient digestibility, growth performance and health of Nile tilapia (Oreochromis niloticus) and rainbow trout (Onchorynchus mykiss)
Date
2024-07-22
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0004-1325-9975
Type
Thesis
Degree Level
Doctoral
Abstract
The rapid expansion of global aquaculture has intensified the needs for sustainable feed alternatives that can replace traditional marine-derived resources like fishmeal (FM) and fish oil. Currently, the use of fermented plant ingredients (FPIs), especially those through solid-state fermentation, in aquaculture production has been gaining significant interest. FPIs have shown potential to enhance nutrient profiles, reduce anti-nutritional factors (ANFs) and improve digestibility and growth in fish, thereby offering a sustainable solution to the challenges posed by conventional feeds. In the present thesis, a comprehensive meta-analysis was conducted to assess the impact of FPIs on the specific growth rate (SGR) across carnivorous, omnivorous and herbivorous fish species. The results revealed significant disparities in SGR when replacing fishmeal (FM) with FPIs in carnivorous fish (P < 0.05). In contrast, herbivorous, and omnivorous fish demonstrated promising adaptability to FPIs when replacing FM (P > 0.05). Additionally, FPIs resulted in better SGR in all fish species when comparing to their corresponding unfermented raw ingredients (P < 0.05).
The nutritional effects of feeding unprocessed canola meal (RCM) and candida utilis-fermented canola meal (CFCM) were explored in two eight weeks trial with Nile tilapia and rainbow trout. After fermentation, the canola meal (CM) showed enhanced amino acid content with reduced anti-nutritional factors (ANFs). The crude protein (CP) digestibility of CFCM was significantly higher in rainbow trout (P < 0.05), while no significant difference was observed in nutrient digestibility Nile tilapia (P > 0.05). Results indicated that, while unprocessed canola meal (RCM) negatively influenced Nile tilapia growth, CFCM could be integrated up to 600 g/kg without any detrimental effects on growth performance. Additionally, rainbow trout displayed improved growth performance when fed CFCM over RCM (P < 0.05). The gene expression of specific cytokines in the distal gut of both fish species fed increasing dietary levels of RCM and FCM, were also examined. Results indicated that CFCM has potential as an alternative protein source when included up to 600 g/kg in diets for tilapia, while rainbow trout exhibited less adverse effects when fed FCM compared to RCM.
In conclusion, FPIs, especially CFCM, hold significant promise in aquaculture. This suggests potential sustainable alternatives to FM without compromising fish growth and health.
Description
Keywords
Yeast Fermentation, Anti-nutritional Factors, Fermented Canola Meal, Fish Meal Replacement, Fish Feed
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Animal and Poultry Science
Program
Animal Science