Fish, laboratory conditions and feeding trials Essay
Chapter 3MATERIALS AND METHODS3.1 Experimental dietsThe commercial natation tilapia pellets ( Cargill’s premium extruded starter/grower Tilapia provenders ) incorporating no added OrgacidsThulium-AQUA ( Control ) and 2 % OrgacidsThulium-AQUA ( Treatment ) which manufactured and purchased by Cargill Sdn. Bhd. , Malaysia were applied in the present survey. The proximate composing of both experimental diets was summarized in Table 4.
1 which indicated that preparation method was precisely the same apart from the inclusion of 2 % microencapsulated organic acids ( 2 % MOAB ) . To avoid provender spoilage, all commercial provender pellets which stored in airtight polythene zipped bags ( Plate 3.1 ) were kept in a icebox to stamp down the growing of mycobiota.
jpg”/>Plate 3.1 Commercial drifting pellets from Cargill Sdn. Bhd.3.2 Fish, research lab conditions and eating testsA sum of 500 GST fingerlings were obtained from hatchery of Trapia Malaysia Sdn. Bhd.
in Banding, Perak ( Plate 3.2 ) . Fingerlings ( Plate 3.3 ) were fed with commercial Tilapia starting motor provender twice daily and acclimatized in an indoor 1000-L rectangular fibreglass armored combat vehicle for 2 hebdomads before originating the eating tests.After acclimatisation period, group of 15 evident healthy GST fingerlings with about similar size ( 15.96 ± 0.03g ) were starved for 24 hours, weighted and allotted indiscriminately into each of 8 fish tanks ( n=15 fish/aquarium ) .
Plate 3.4 demonstrates the glass-made, rectangular-shaped, 95-L fish tank ( 61.0cm x 30.
5cm ten 50.8cm ) set-up with H2O flow-through system that used in present survey. An air-stone was placed into each fish tank to supply changeless aeration and de-chlorinated H2O was delivered to each fish tank with an mean flow rate of 22.4Lh-1.
A photoperiod of 14 hours in light and 10 hours in darkness from fluorescent visible radiation was maintained daily. The H2O quality parametric quantities such as temperature, dissolved O and pH in the civilization system were maintained at coveted conditions.Each experimental diet was performed in 4 replicates and the fish were cultured for 7 hebdomads at Fish Nutrition Laboratory, USM. GST were hand-fed twice daily in a regular clip interval ( 09:00 and 17:00 ) to evident repletion. Amount of provender offered in each fish tank was recorded daily except on trying twenty-four hours as there was no provender given to GST. GST from each fish tank were batch-weighed hebdomadal to find the growing public presentation. Throughout the eating tests, some of the GST in certain fish tanks were contending with each other due to their aggressive behaviour. Hence, the upper lips of the GST were removed to avoid hurts or mortality to other fingerlings.
2 Nursery coop of Trapia hatchery in Temengor lake.Plate 3.
4 Aquaria set-up used in present survey3.3 Fecal matters aggregationAfter four hebdomads into the feeding test, fecal matters were collected one time day-to-day from each fish tank. Before roll uping the fecal matters, all fish tanks were siphoned exhaustively to dispatch the nightlong provender and fecal matters residues. Fictile cyberspaces were placed at the underside of each fish tank to forestall fecal matters disturbed or eaten by GST ( Plate 3.5 ) .
Within 6 hours, the long and integral faecal strands were carefully siphoned into a all right mesh cyberspace and collected into falcon tubing. The falcon tubings were so stored in the icebox for subsequent evident digestibleness analysis ( Plate 3.6 ) .
Faecal samples collected from each fish tank were pooled, oven dried and finely land before analysis.[ Final mean weight ( g )–Initial mean weight ( g ) ]Initial mean weight ( g )
- Specific growing rate ( SGR, % twenty-four hours-1)
= 100 tens( ln concluding–ln initial fish weight )Number of yearss
- Feed transition ratio ( FCR )
= Wet weight addition ( g )Entire protein intake ( g )
- Survival rate ( % )
= 100 tensConcluding fish figureInitial fish figure3.8 Evaluation of fish organic structure indices
- Hepatosomatic index ( HSI, % )
= 100 tensLiver weight ( g )Body weight ( g )
- Viscerosomatic index ( VSI, % )
= 100 tensViscera weight ( g )Body weight ( g )
- Intraperitoneal fat index ( IPF, % )
= 100 tensIntraperitoneal fat weight ( g )Body weight ( g )
- Hematocrit ( % )
Figure 4.3 Consequence of MOAB on evident alimentary digestibleness ( % dry weight footing ) of GST after 7 hebdomads of feeding tests.4.7 Total feasible bacterial count and Lactic acid bacterial countDecrease in entire feasible bacterial count of both expelled fecal matters and intestine was observed in GST fed 2 % MOAB diet ( Figure 4.4 ) . From the information yielded, GST fed 2 % MOAB discharged important less entire bacteriums per g of fecal matters ( P & A ; lt ; 0.05 ) . In add-on, figure of adherent bacterial in intestine was besides declined but insignificantly in GST fed 2 % MOAB diet compared to GST fed control diet ( Appendix G ) . However, there were no any Lactic acid bacterial was detected in neither fecal matters nor intestine of GST fed control or 2 % MOAB diets.Figure 4.4 Consequence of MOAB on entire arable bacterial count ( x106CFU/g ) of the GST expelled fecal matters, HL and TS with two different experimental diets