Effect of phytase supplementation on the growth, mineral composition and phosphorus digestibility of African catfish (Clarias gariepinus) juveniles

This study investigates the effect of phytase supplemented diets on growth, bone mineralization and phosphorus digestibility of African catfish Clarias gariepinus. A 40 % crude protein diet was produced using fishmeal, soybean meal, lima bean meal, groundnut cake and yellow maize as ingredients. Diets E0, E1, E2 and E3 were supplemented with phytase (Natuphos microbial phytase, 5000 FTU/g; BASF) at 0, 1000, 2000 and 4000 FTUkg -1 feed respectively. The diets were fed to C. gariepinus (25.28 ± 0.03g) at 3 % body weight at two equal instalments daily. After 98 days of feeding, results indicated that mean weight gain (MWG) were significantly higher (p<0.05) in fish fed E1 (63.82 g), E2 (66.71 g) and E3 (64.98 g) than E0 (55.76 g). Feed consumed was marginally highest in E2 (110.91g) and least in E0 (103.83g). Phosphorus digestibility were significantly lower (p>0.05) in E0, with phytase resulting in over 28 % improvement. Calcium, phosphorus and zinc were highest in the carcass of E3 (30.23 mg/g, 31.96 mg/g and 52.78 µg/g respectively) and least in E0 (18.81 mg/g, 24.83mg/g and 35.55 µg/g respectively). Results also indicate significant increase (p<0.05) in bone minerals of fish fed diets E1, E2 and E3. Faecal phosphorus decreased with increase in phytase supplement from 15.98 mg/g in E0 to 11.01 mg/g in E3. Value of fish produced and profit index were significantly higher (p<0.05) in fish fed diets supplemented with phytase.Keywords: Clarias gariepinus, Growth, Digestibility, Calcium, Phosphorus, Zin

GROWTH PERFORMANCE, GUT ECOLOGY, IMMUNOCOMPETENCE AND RESISTANCE OF Oreochromis niloticus JUVENILES FED DIETARY Curcumin longa

U radu je istraživana ekologija crijeva i imunokompetencija nilske tilapije Oreochromis niloticus te njena otpornost na Aeromonas hydrophila nakon 12 tjedana hranidbe hranom koja sadrži kurkumu Curcumin longa. Smjese su formulirane da sadrže 30% sirovog proteina (TC1, TC2, TC3, TC4 i TC5) s 0% (kontrola), 0,25%, 0,5%, 0,75% i1,0% praha kurkume. Hrana je ponuđena skupinama O. niloticus (prosječna masa 0,5 ± 0,15 g) u triplikatima kroz trajanje od 84 dana. Rezultati su ukazali da je skupina T3 imala najveću završnu masu (4,79 ± 0,04 g) i odgovara skupini s najvećim unosom hrane. Značajno viša (p0,05) u različitim tretmanima. Međutim, broj bijelih krvnih stanica (WBC) bio je značajno viši u TC1 (kontrola). Utvrđena je poboljšana imunokompetentnost kod skupina sa suplementiranom hranom. Slično tome, došlo je i do boljeg oksidativnog odgovora u skupinama tretiranim kurkumom i to u obliku smanjene hidrogen peroksidaze, povećanim ukupnim proteinima i glutation- peroksidazom. Smrtnost riba se kretala od 25% u TC4 do 95% u TC1 nakon ispitnog testa s A. hydrophila. Ovo istraživanje je ukazalo kako je uključivanje C. longa od 0,5% korisnije kada se uzmu u obzir rast i zdravstveno stanje mlađi O. niloticus.The growth, gut ecology and immunocompetence of Oreochromis niloticus and the resistance to Aeromonas hydrophila were investigated after been fed with diets containing dietary Curcumin longa for 12 weeks. Diets were formulated to contain 30% crude protein with diet TC1, TC2, TC3, TC4 and TC5 having 0% (control), 0.25%, 0.5%, 0.75% and 1.0% turmeric powder, respectively. Diets were allotted to groups of O. niloticus (mean weight of 1.29± 0.15 g) and replicated thrice for 84 days. Results showed that the highest mean final weight (4.79±0.04 g) was obtained in TC3 and corresponded to the treatment with the highest feed intake. A significantly high (p0.05) across treatments. However, white blood cell (WBC) count was significantly higher in TC1 (control). There was an improved immunocompetence, as aspartate aminotransferase (AST) progressively reduces in fish fed supplements. Similarly, there was a better oxidative response in the treated groups with reduced hydrogen peroxidase, increased total protein and glutathione peroxidase. Mortality ranged from 25% in TC4 to 95% in TC1 after the challenge test with A. hydrophila. This study showed that C. longa inclusion at 0.5% is more beneficial when growth and health status of O. niloticus juveniles are considered

Proximate and mineral compositions of Schilbe mystus (Linne 1758) and Heterotis niloticus (Cuvier 1829)

The nutrient composition of fish has been established to vary with species and growing environment. Hence, the proximate composition and mineral contents of Schilbe mystusand Heterotis niloticus in Lake Alau were investigated to determine their nutritive value. A total of 10 fresh samples of each species obtained from fishermen catch (weight: 315.20 – 436.10 g) were separately stunted, de-gutted, washed, grounded and analyzed for moisture, crude protein, fat, ash, carbohydrate, calcium, iron, sodium, potassium and magnesium following standard procedures. Mean moisture (62.95 ± 1.97 %) and ash (2.40 ± 0.21 %) contents were higher in H. niloticus, while crude protein content (35.20 ± 1.48 %) was significantly higher (p<0.05) in S. mystus. Also, the fat content was significantly higher in H. niloticus (12.20 ± 1.08 %) than in S. mystus (3.97 ± 0.39 %). Carbohydrate value was higher (p>0.05) in S. mystus (2.20 ± 0.33 %) than in H. niloticus (1.85 ± 1.01 %). Values of iron (1.16 ± 0.35 %) and potassium (5.50 ± 0.50 %) were marginally higher in S. mystus, while sodium (85.10 ± 12.81 %) was significantly higher (p<0.05) in S. mystus. This study thus provides baseline information on the present nutritive status of the two freshwater finfish species in Lake Alau.Keywords: Nutritive value, Schilbe mystus, Heterotis niloticus, Fish food, Lake Ala

Growth Performance, Gut Ecology, Immunocompetence and Resistance of Oreochromis niloticus Juveniles Fed Dietary Curcumin longa

The growth, gut ecology and immunocompetence of Oreochromis niloticus and the resistance to Aeromonas hydrophila were investigated after been fed with diets containing dietary Curcumin longa for 12 weeks. Diets were formulated to contain 30% crude protein with diet TC1, TC2, TC3, TC4 and TC5 having 0% (control), 0.25%, 0.5%, 0.75% and 1.0% turmeric powder, respectively. Diets were allotted to groups of O. niloticus (mean weight of 1.29± 0.15 g) and replicated thrice for 84 days. Results showed that the highest mean final weight (4.79±0.04 g) was obtained in TC3 and corresponded to the treatment with the highest feed intake. A significantly high (p0.05) across treatments. However, white blood cell (WBC) count was significantly higher in TC1 (control). There was an improved immunocompetence, as aspartate aminotransferase (AST) progressively reduces in fish fed supplements. Similarly, there was a better oxidative response in the treated groups with reduced hydrogen peroxidase, increased total protein and glutathione peroxidase. Mortality ranged from 25% in TC4 to 95% in TC1 after the challenge test with A. hydrophila. This study showed that C. longa inclusion at 0.5% is more beneficial when growth and health status of O. niloticus juveniles are considered