Page 40 - New additives and ingredients in the formulation of aquafeeds

Optimizing the
application
regime to
improve feed
utilization
and fillet yield
in Pangasius
catfish
farming
Pangasius catfish production has grown very rapidly in Vietnam to reach
more than a million mt in recent years. This rapid growth has resulted in
the industrialization of feed production as well as in culture technology.
Whereas traditional catfish farmers produce farm-made feeds by mixing
and cooking local raw materials in large kettle cookers, larger integrators
have installed state-of-the-art extrusion lines producing compound feed
following stringent quality control schemes. Due to declining market prices
for Pangasius, farmers and feed producers are continuously searching for
ways to improve feed performance and optimize fillet yield to maintain
profitability.
The optimal application of novel feed additives requires field evaluations
to provide information in terms of farm economics and processing qualities
of the fish. The effect of different application regimes for a digestibility
enhancer was evaluated for Pangasius hypophthalmus (“Tra”) in two
farm locations of Hung Vuong Mien Tay breeding joint stock company in
the Mekong Delta (Van Halteren et al., 2009). The various treatments
differed in the inclusion level of the digestibility enhancer (AQUAGEST®
OMF, Nutriad, Belgium) in the extruded feed and the period during which
it was applied during the production cycle (Table 4). Trials were carried out
under standard production protocols in earthen ponds of approximately
5-6,000 m2 (Trial site Tra Vinh) and 8,500-12,000 m 2 (trial site Sa Dec). The
ponds were stocked with juveniles with an average size of 15g at a density
of 45-50 fish/m2 in Tra Vinh, and 30 g fish were stocked at 34-38 fish/m2
in Sa Dec.
38 Innovative approaches to reduce feed cost in aquaculture: optimizing nutrient utilization and gut health
Photo 4: Feeding trial
ponds and harvest
of Pangasius catfish
in Vietnam (with
courtesy of Alexander
van Halteren)