| dc.description.abstract | The present research was conducted to investigate the effect of different feeds on growth and breeding
performance of swordtail fish (Xiphophorus helleri) for 140 days (from 20 June to 7 November 2015)
in aquarium. The treatments were T1 (formulated sinking pellet feed of 37.6% protein), T2
(commercial floating pellet feed Mega having 27.6% protein) and T3 (commercial floating pellet feed
Fast red having 29.5% protein) with three replications each. Each aquarium was stocked 20 fry (mean
initial weight 0.05±0.001g and length 1.68±0.16cm). During the study period, the fry were fed twice a
day up to satiation level. At the end of experiment the highest mean weight gain (2.60 ± 0.16g) was
found in T3 and the lowest (1.73±0.26g) in T1. The highest mean length gain (4.39 ± 0.05cm) was in
T3 and the lowest (3.54 ± 0.13cm) in T1. The highest SGR (2.83±0.04) was found in T3 where as the
lowest (2.55±0.11) in T1. The highest FCR (1.99) was in T1 while the lowest (1.32) in T3. The highest
survival rate (86.67±2.88%) was recorded in T3 and the lowest (65±5%) in T1. There were significant
differences (P<0.05) between T1 and T3 in case of weight gain, length gain, SGR and FCR. In these
cases, there was no significant difference between T1 and T2 or T2 and T3 except length gain. Survival
rate of T2 was significantly different from T1 and T3. The highest GSI% (9.48±0.66), HSI%
(3.16±0.21), relative fecundity (18.48±3.20), number of spawn (36±4), weight of spawn (0.0049
±0.0006g) and length of spawn (0.76±0.06cm) were found in T3 and the lowest GSI% (5.92±0.62),
HSI% (2.33±0.39), relative fecundity (11.55±1.55), number of spawn (22.33±2), weight of spawn
(0.0046±0.0006g) and length of spawn (0.57±0.06cm) in T1. There were significant differences
between T1 and T3 in case of GSI, HSI, number of spawn and length of spawn. The water quality
parameters were monitored at 20 day intervals and their ranges were: temperature 26.8-27.8
C,
dissolved oxygen 6-7.5 mg/l, pH 6.26-7.46, ammonium 0.258-0.34, alkalinity 6.4-7 mg/l, nitrite 0.00
mg/l and Phosphate 0.50 mg/l. There was no significant difference among the treatments in water
quality parameters. Possible reasons for lower growth and breeding performance of T1 may be its
higher content of fiber and also mustard oil cake ingredient containing antinutritional factor
glucosinolate, enzyme thioglucosidase and toxic erucic acid and growth reducing factor in rice bran.
So, it may be recommended that the commercial pelleted floating feed “fast red” is the best feed
among the experimental feeds for growth and breeding performance of swordtail and the formulated
feed may be used for further experiment after reducing fiber content, steaming rice bran and a soaking
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treatment of mustard oil cake. | en_US |
