Page 32 - New additives and ingredients in the formulation of aquafeeds

Preselected synergistic blends of digestibility enhancing additives are being
screened for their capability to improve growth and food conversion in a
number of model species (rainbow trout Oncorhynchus mykiss; European
seabass Dicentrarchus labrax; Nile tilapia Oreochromus niloticus ; Tra catfish
Pangasius hypophthalmus). Test feeds are formulated to be representative
for average industry standards per species and processed using industrial
extrusion technology. Trials executed under controlled lab conditions have
revealed enormous differences in efficacy among different additive concepts
designed to improve digestion (Figure 3). Some digestibility enhancers seem
to be incompatible with the digestive physiology of certain fish species and
affected fish performance negatively. The addition of selected blends of
digestive aids improved growth/feed conversion ratio in rainbow trout (up
to 6% improvement of growth and 8% on FCR versus non-supplemented
control group), Nile tilapia (+5/-9% on growth/FCR), pangasius catfish
(+6/-15% on growth/FCR), and European seabass (+5/-5% on growth/FCR).
These results show the potential of digestibility enhancers to improve feed
efficiency in fish farming, resulting in improved economics, more sustainable
use of feed ingredients and reduced environmental impact.
Figure 3: Screening
of synergistic blends
of digestibility en-
hancers at lab scale
comparing product
efficacy and cost-
efficiency for each
fish species
Fig. 3: Screening of synergistic blends of digestibility enhancers at lab scale compari
product efficacy and cost-efficiency for each fish species.
Data sh w results for growth (SGR, %/day) and fe d co version ratio (FCR) relative
the perf rmance of the non-supplemented control group. Feeding trials were run in
triplicate tanks for ainbow trout (trial duration 64 days; starting from 19g); Nile tila
(56 days; starting from 9g); Pangasius catfish (70 days starting fr m 16g); and Euro
seabass (84 days; starting from 224g) (Coutteau et al., 2010).
30 Innovative approaches to reduce feed cost in aquaculture: optimizing nutrient utilization and gut health
rainbow trout - growth & fcr (% change vs control)
NILE tilapia - growth & fcr (% change vs control)
pangasus catfish - growth & fcr (% change vs control)
european seabass - growth & fcr (% change vs control)
8 %
6 %
4 %
2 %
0 %
-2 %
-4 %
-6 %
-8 %
6 %
4 %
2 %
0 %
-2 %
-4 %
-6 %
-8 %
-10 %
10 %
5 %
0 %
-5 %
-10 %
-15 %
-20 %
6%
4%
2%
0%
-2%
-4%
-6%