Page 36 - New additives and ingredients in the formulation of aquafeeds

The low cost feed performed significantly worse compared to the control
feed in most parameters, particularly in terms of survival, feed conversion
and fileting yield. The addition of 2 kg/MT of the feed additive was only
capable of improving growth but the nutritional impact of reducing the
protein digestibility and amino acid balance in this feed heavily affected the
overall performance, particularly FCR and survival. The trials results showed
that tilapia are highly sensitive to reducing the quality of the dietary protein
in the feed. The digestibility enhancer was not capable of rectifying the
effect of inferior nutritional specifications, which finally resulted in a less
cost-efficient feed for the producer.
Considering the cost efficiency of the different feeds, the optimal additive
treatment (3 kg/MT throughout the production cycle) improved farm
revenues with 17% compared to the unsupplemented control group and
showed a return on investment (ROI) of 3.8:1 (Figure 5). Reducing the
additive inclusion to 1.5 kg/MT of feed once fish reach 350 g still resulted
in 7% improved revenues compared to the unsupplemented control group
and a ROI of 2.1:1. The application of the low cost feed supplemented with 2
kg/MT of the additive resulted in important economic losses (10% reduced
revenues compared to control).
This study clearly indicated the potential of improving cost efficiency of
tilapia feeds through the use of digestibility enhancing additives. The
results showed the importance of maintaining the nutritional balance in
the feed in order to maximize the benefits of a digestibility enhancing
concept. It is important to note that the economic impacts of performance
enhancing feed additives (having a relatively stable cost, independent from
standard commodity ingredients) increases dramatically with increasing
ingredient cost.
Figure 5: Economic evalua-
tion of different application
strategies for a feed additive
in tilapia farming. Feed ingre-
dient costs used for this study
dated early 2012. Data show
change of farm revenues and
return of investment, relative
to the non-supplemented con-
trol group. Treatment groups
differ in inclusion of the feed
additive and formulation:
AG3 (control feed + 3 kg/MT
throughout the production
cycle), AG3/1.5 (control feed
+ 3 kg/MT till 350 g; followed
by 1.5 kg/MT till harvest), LC/
AG2 (low cost feed + 2 kg/MT)
34 Innovative approaches to reduce feed cost in aquaculture: optimizing nutrient utilization and gut health
Additional revenue
(% of control)
ag3
20 %
15 %
10 %
5 %
0 %
-5 %
-10 %
-15 %
ag3/1.5 LC/ag2
Return on investment
(ROI)
ag3
4
3
2
0
-1
-2
-3
-4
ag3/1.5 LC/ag2
1