Browsing by Author "Lamtane, Hieromin A."

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    Comparative Performance of Mixed-Sex and Hormonal-Sex-Reversed Nile Tilapia Oreochromis Niloticus and Hybrids (Oreochromis Niloticus × Oreochromis Urolepis Hornorum) Cultured in Concrete Tanks
    (Springer Link, 2016) Mbiru, Moses; Samwel Mchele Limbu; Chenyambuga, Sebastian W.; Lamtane, Hieromin A.; Tamatamah, Rashid; Madalla, Nazael A.; Mwandya, Augustine W.
    Uncontrolled breeding and precocious maturity in Nile tilapia, Oreochromis niloticus can be avoided by using all-male population. This study compared the growth performance, survival rate, condition factor and final fish tank biomass (yield) of mixed-sex and hormonal-sex-reversed O. niloticus and hybrids (O. niloticus × O. urolepis hornorum) cultured in tanks. Sex-reversed males were produced by feeding newly hatched fry with a diet containing 60 mg of 17α-methyltestosterone for 28 days. Fourteen O. niloticus with initial mean weight (±standard error) of 0.50 ± 0.04, 0.48 ± 0.06 and 0.46 ± 0.01 g for mixed-sex, sex-reversed and hybrids, respectively, were separately stocked in triplicate tanks at a density of two fish m−2 and fed a 300 g kg−1 crude protein diet for 12 weeks. Results showed that hybrids had significantly higher final mean weight (31.41 ± 0.33 g) than hormonal-sex-reversed (25.82 ± 1.51 g) and mixed-sex O. niloticus (19.50 ± 1.26 g; p < 0.05). Similarly, sex-reversed O. niloticus had significantly higher final mean weight than mixed-sex (p < 0.05). The condition factor of hybrids (1.71 ± 0.05) was significantly higher than that of sex-reversed (1.46 ± 0.01; p = 0.001) and mixed-sex O. niloticus (1.43 ± 0.01; p = 0.001). Survival rate was not significantly different among treatments (p = 0.445). The final fish tank biomass was significantly higher in hybrids (535.24 ± 31.67 g tank−1) and hormonal-sex-reversed (486.52 ± 33.70 g tank−1) than mixed-sex O. niloticus (330.05 ± 17.08 g tank−1; p < 0.05). This study demonstrates that hybrids have superior growth performance and condition factor than sex-reversed and mixed-sex but have similar yields to hormonal-sex-reversed O. niloticus. These results suggest that O. niloticus farmers can improve growth rate and yield by rearing hybrids without affecting survival rate.
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    Effect of initial stocking size of the predatory African sharptooth catfish (Clarias gariepinus) on recruits, growth performance, survival and yield of mixed-sex Nile tilapia (Oreochromis niloticus) in concrete tank culture system
    (Springer, 2015-01-21) Samwel Mchele Limbu; Amon P., Shoko; Lamtane, Hieromin A.; Shirima, Evantuce D.; Kishe-Machumu, Mary A.; Mgana, Huruma F.; Mgaya, Yunus D.
    Prolific breeding and production of high percentage of recruits are main problems in mixed-sex Nile tilapia (Oreochromis niloticus) culture in earthen ponds. The current study assessed the efficiency of different sizes of African sharptooth catfish (Clarias gariepinus) in controlling recruitment in mixed-sex Nile tilapia cultured in tanks and its effect on growth performance, percentage survival and yield. Three treatments consisting of triplicate ponds stocked with mixed-sex Nile tilapia in monoculture and in polyculture with large (62.50 ± 3.26 g) and small (40.00 ± 2.68 g) African sharptooth catfish were fed on a 297.50 g kg-1 crude protein diet for 126 days. Results showed that, the number of recruits was significantly lower in larger African sharptooth catfish predator than smaller ones and monoculture of Nile tilapia. Polyculture with larger African sharptooth catfish resulted in significantly higher growth performance of Nile tilapia. Large African sharptooth catfish in polyculture reduced the amount of small, low-value recruits, while the yield of large and high value Nile tilapia was increased. This study revealed that fish farmers can reduce prolific breeding, obtain higher growth performance and produce larger size of marketable Nile tilapia by predominantly stocking ponds with large African sharptooth catfish predator of at least 60 g.
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    The role of fish-poultry integration on fish growth performance, yields and economic benefits among smallholder farmers.
    (Taylor & Francis, 2019-04-15) Shoko, Amon P.; Samwel Mchele Limbu; Lamtane, Hieromin A.; Kishe-Machumu, Mary A.; Sekadende, Baraka; Ulotu, Eusebia E.; Joram, Masanja C.; Mgaya, Yunus D.
    Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.
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    Supplemental Effects of Mixed Ingredients and Rice Bran on the Growth Performance, Survival and Yield of Nile Tilapia, Oreochromis Niloticus Reared in Fertilized Earthen Ponds
    (Springer, 2016) Samwel Mchele Limbu; Shoko, Amon P.; Lamtane, Hieromin A.; Kishe‑Machumu, M. A.; Joram, M. C.; Mbonde, A. S.; Mgana, H. F.; Mgaya, Yunus D.
    Unaffordability of commercial feeds to semi‑intensive Nile tilapia, Oreochromis niloticus farmers has led to reliance on supplemental feeding and fertilization for nutrition of their fish without a scientific basis. This study compared the growth, survival, condition factor and yield performance of O. niloticus fed on mixed ingredients (MI) and rice bran alone (RB) diets reared in fertilized earthen ponds in small scale farmers’ ponds. The study also determined phytoplankton composition, biomass and abundance in the experimental ponds. Quadruplicate ponds were stocked with O. niloticus and African sharptooth catfish, Clarias gariepinus at a stocking ratio of 1:3. The initial mean weights of O. niloticus and C. gariepinus were 14.62 ± 0.61 and 20.34 ± 1.44 g respectively. The fish were fed on MI and RB diets with protein content of 184.74 and 126.06 g kg−1 respectively for 270 days. The results showed that growth performance, survival rate and condition factor of O. niloticus were not affected by either feeding with MI or RB diet (p > 0.05). Moreover, there were no significant differences obtained in phyto‑plankton biomass and abundance in O. niloticus ponds fed on the two diets (p > 0.05). Furthermore, feeding O. niloticus either on MI or RB diet did not affect the net and gross fish yields (p > 0.05). The study revealed that the use of either MI or RB diet does not significantly affect the performance of O. niloticus cultured in semi‑intensive earthen ponds where natural food organisms are an integral part of the culture system. Rice bran could be used for semi‑intensive culture of O. niloticus in fertilized ponds to boost the production based on its availability and low cost.