Growth and Economic Evaluation of Different Fish Species for Culture in Uganda’s Mid Altitude Areas Using Local Feeds

Abstract

Background and Objective: The East African high-altitude areas remain ecologically challenging to tropical native farmed fish species, the Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) yet the potential for cold-water fish culture is as well unexploited. This study describes the effects of environmental quality and local feed on the growth and economic performance of selected fish species for 5 months along the slopes of Mountain Elgon Uganda. Materials and Methods: Three earthen ponds each 200 m3 by volume were conditioned with hydrated lime at 0.1 kg mG3 for a week. The ponds were stocked with juveniles of Rainbow trout (Oncorhynchus mykiss), Nile tilapia and Mirror carp, averaging 1.5±0.1, 17.9±2.2 and 2.0±0.2 g (±SE), respectively. The fish were fed to satiation daily on 35% C.P local feed for 5 months. Water quality and growth data were collected daily and monthly, respectively. Performance parameters were computed and analyzed using univariate ANOVA and regression analysis in SPSS20. Results: There was a highly significant difference (p<0.001) in mean body weight gain (g/day) between Rainbow trout and the Nile tilapia (mean diff 0.0788, p<0.001) and Mirror carp (mean diff 0.087, p<0.001) and between Rainbow trout and the two species combined (mean diff 0.016, p = 0.006). The highest weight gain (4.8 g/day) overall was demonstrated by Mirror carp in the 4th month of growth. The mean relative condition (Kn) for respective species (p<0.05) were all <1. The Mirror carp was the most profitable, at Ugshs 4, 130, 463 (44.9%) of total revenue, while trout incurred over 92.1% (Ugshs -3, 974, 994.5) losses. Mirror carp demonstrated better economic viability with the experimental feed in the area, however, this can be much better with improved management. Conclusion: The observed growth patterns were consistent with temperature variation and feed quality, thus, Nile tilapia performed poorly due to low water temperature and Rainbow trout was worse due to poor feed quality that negatively influenced visibility and feed intake.