Six iso-energetic (352 kcal gross energy/100 g feed) and iso-nitrogenous (32% crude protein) experimental diets containing one of the four algae (Anabaena cylindrica, AN; Nostoc salbasa, NS; Spirulina platensis, SP; Westleopsis prolifica, WS) as the major dietary ingredient (40% of the total composition) or algal meal mixture with supplemental protein (AMM+PS) or only algal meal mixture (AMM) were tested against a control diet to find out the suitability of algal meal to develop practical diet for rohu fingerling. The experimental fish of average weight 2.0 ± 0.1 g were fed at a rate equaling 4% of body wt/day for 8 weeks at an experimental temperature of 28 ± 2°C. Significant (p<0.05) enhancement in growth rate was observed in the groups fed with WS (571%) followed by the groups fed with NS (517.6%) and SP (502.8%) as compared to that of the groundnut oil, rice bran and soybean meal based control diet (406.4%). Fingerlings fed with algal meal mixture (AMM) gained least (255.2%). Diet with WS performed well in terms of FCR, PER, HSI, MR and CF when AMM showed least efficiency. Fish fed with SP showed better protein utilization (ANPU%) as compared to the other dietary groups. Carcass protein was not affected by any diet. The MUFA and PUFA of liver and PUFA of muscle increased over the initial value fed with control and experimental diets. But the MUFA of muscle with these diets are less than the initial. The SFA content in all diets of both the tissues is either same or less than initial value except with AMM diet. The total n-3PUFA in liver increased with all diets over the initial value. But this increase in muscle was observed only with AN, NS, WS and AMM+PS diets. The n-6PUFA of liver and muscle remained either same or increased with all diets over initial value. This study showed that individual algal diets gave better result in growth performance and PUFA content. Among all the algal diets WS found to be the best.
Kirti Mishra, Patra S. K. and Kasturi Samantaray