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Collection of Fecal
Material of Fish for the Measurement of Digestibility
Collection of Fecal Material
(using UA system) of Fish for the Measurement of Digestibility
 Knowledge
of apparent digestibility of feed ingredients for fish
provides a rational basis for the formulation of diets.
Digestibility estimations in fish depend on the collection of
representative sample free of uneaten feed particles and the
use of a digestions indicator (indirect methods). There are
three methods/systems that have been adopted in several
labortries around the world are most likely to produce
meaningful estimates of digestibility of nutrients if used
correctly (Bureau and Cho, 1999)
- the system of Ogino et al 1973) in which the feces are
collected by passing effluent water from the fish tanks
through a filtration column (TUF column)
- Cho et al ., 1975 in which settling column is used to
separate the feces from the effluent water (Guelph system) and
- Choubert et al., 1979 in which mechanically rotating the
screen is used to filter out fecal material (St. Pee system)
Development of UA System:
Feedstuff digestibility assessment in fish is an essential
prerequisite in determining the nutritionally adequate diets.
Unfortunately, the research on digestibility aspect in our
culturable species (major carp) was never given due
consideration.
The main barrier for conducting digestibility research was the
lacking of facilities in term of fecal collecting system.
 In
view of importance of digestibility research for developing
fish diet, a settling column system has recently been
developed on the principle of Guelph system (Canada) by
utilizing the local resources and designated the name as UA
system.
This system consists of two parts: voiding tank and fecal
settling column (figures 1 and 2).
Each voiding tank measure 60cm x 45cm and have a slop bottom,
open into settling column (8cm diameter x 65cm high).
The upper part of settling column is connected with drainpipe,
open into common drain system.
The velocity of the water flow is adjusted to minimize
settling of the feces in the settling column.
Under normal operation, it has been observed that large feces
particles are settled in the settling column within 2-4
minutes of being voided by the fish.
A series of eighteen tanks allow the determination of
digestibility of eight ingredients (with two replications of
each ingredients) and remaining two tanks being devoted to the
reference diet (figures 3 and 4).
With the development of UA system, the research on
digestibility has now become possible. Presently, two students
of Ph.D are conducting research on apparent digestibility
coefficient (ADC) of different ingredients in fish (major
carps) by using newly developed UA system.
LITERATURE CITED
Burea, D.P and Cho C.Y; 1999. Measuring digestibility in Fish.
Fish Nutition Research Lab. University of Guelph, Canada.
Choubert, G.Jr., Noue J.de la and Luquet, P (1979) Continuous
quantitative automatic collector for fish feces. Prog. Fish.
Cult. UI, 64-67.
Ogino, T., Kakino, J and Chen, M.S 1973. Protein nutrition in
fish. Bull. Jap. Soc.Sci. Fish., 519-525.
Muhammad Salim
E-Mail Address. drsalimuaf@hotmail.com
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