الفهرس 
Physico-chemical properties of tilapia pondsOnly 14 pages are availabe for public view
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Abstract
Effect of certain chemical compounds on the growth rates and reproduction of the Nile tilapia
(Oreochromis niloticus)
Abstract
This study was based on rearing of Nile tilapia, O.niloticus for 180 days with initial weight ranging from 16.5 to 19.0g. The fish were fed on artificial diet containing some growth promoters (vitamin C, vitamin E and cobalt chloride) as experimental treatments, to clarify the effect of these promoters on growth rates, feed utilization, biological conditions and biochemical parameters (total protein, total lipids, glycogen and cholesterol) of fish organs (liver, muscles and gonads). In addition, to investigate the role of these promoters in alleviating pollution effects on some organ tissues (liver and gonads) of the reared fish.
The experimental treatments were conducted in 8 groups occupied 8 ponds as follows:
- Pond I (untreated group) was fed on the basal diet only.
- Pond II was fed on the basal diet with 50mg vit. C/kg diet.
- Pond III was fed on the basal diet with 120mg vit. E/kg diet.
- Pond IV was fed on the basal diet with 0.01mg.CoCl2/fish/day. i.e., by adding 0.5mg of CoCl2 daily to the diet of the pond (50 fish).
- Pond V was fed on the basal diet with vit. C + vit. E (at the same concentration in ponds II and III).
- Pond VI was fed on the basal diet with vit. C + CoCl2 (at the same concentration in ponds II and IV).
- Pond VII was fed on the basal diet with vit. E+ CoCl2 (at the same concentration in ponds III and IV).
- Pond VIII was fed on the basal diet with vit. C + vit. E + CoCl2 (at the same concentration in ponds II, III and IV).
At the end of the rearing period (180 days) the following results were obtained:
1. Growth performance:
a- Growth in length: It was found that, pond II (vit. C) and pond VII (vit. E + CoCl2) showed the highest values of fish length.
b- Growth in weight: ponds II and IV gave the highest values in weight.
c- Percentage weight gain showed the highest values in ponds II and IV.
d- Specific growth rate reached its highest values in ponds II, III, IV and V.
2. Feed utilization:
a- Food conversion ratio showed its optimal value in pond IV.
b- Protein efficiency ratio showed its maximum value in pond II.
c- Protein productive value: showed the lowest value in pond V.
3. Biological parameters:
a- Gonadosomatic index showed its highest values to males and females in pond VIII.
b- Condition factor showed its highest value in pond VIII.
c- Hepatosomatic index gave its highest value in pond IV.
d- Gastrosomatic index gave its highest vale in pond VIII.
4. Fecundity: ponds II, III, and V gave high values in fecundity but the highest value was in pond III.
5. Biochemical analysis: It was in the liver, muscles and gonads.
a- The liver: total protein of the liver increased in pond VIII.
Total lipids icreased in pond III.
Glycogen showed its highest value in pond II.
Cholesterol gave its lowest value in pond III.
b- The muscles: total protein of muscles increased in pond V.
Total lipids showed its highest value in pond III.
Glycogen gave its highest value in pond VIII.
Cholesterol gave its lowest value in pond V.
c- Gonads: the total protein of gonads increased in pond VIII.
The total lipids gave its highest value in pond II.
Glycogen showed its highest value in pond VII.
Cholesterol gave its lowest value in pond V.
6- Histological studies: In the histological study the effect of pollution was noticed on the tissue (liver, ovary and testes)of the reared fish in pond I, then the fish in ponds V and VIII cleared the role of these promoters (vit.C, vit.E and CoCl2) in alleviation of the pollution effect in these tissues of Nile tilapia O.niloticus.