S.S. Giri

Evaluation of Processed Rain Tree (Samanea saman) Pod Meal as a Non-conventional Ingredient in the Diet of Catla catla Fry

Rain tree (Samanea saman) is a fast-growing tropical tree, abundantly grown in India under plantation programmes. The present study was carried out to evaluate the effects of processed rain tree pod (RTP) in the diets of Catla catla fry. Chemical analysis results indicated that RTP is a good source of protein (25.2% CP) and energy (4.88 kcal/g), and contains 1–2% of ether extract with 44% PUFA. Additionally, it contained 7.4% tannins, 2.25% saponin, and 1.57% alkaloids. Water soaking followed by autoclaving of raw RTP reduced tannin and saponin contents. Five iso-nitrogenous test feeds were formulated incorporating raw (F1) and differently processed RTP (F2-F5) at 30% level with groundnut oilcake and rice bran as co-ingredients and fed to Catala catla fry reared in indoor FRP tanks for 60d. Results indicated that fish of raw or processed RTP fed groups did not show any significant (P>0.05) differences in survival (98–99%), average weight gain (0.30–0.31 g), FCR (1.11–1.14) and specific growth rate (SGR; 1.76–1.82%/day). Nonetheless, the protein efficiency ratio (PER) and net protein utilization (NPU) values varied significantly (P<0.05) between the raw and processed RTP groups. It is inferred that the tannin, saponin and alkaloid contents in raw RTP are possibly in the safe level when incorporated at 30% level in the diet of Catla fry. Hence, there appears to be further scope to incorporate the processed rain tree pod meal beyond 30% level in the carp feed.

Evaluation of Jute Leaf as Feed Ingredient for Labeo rohita Fingerlings

A 60 day feeding trial was conducted to evaluate the suitability of jute (Corchorus olitorius) leaf powder, as a dietary protein source for Labeo rohita fingerlings. One control feed without jute leaf JL0 (0%) and four experimental feeds were prepared with graded levels of jute leaf powder viz; JL10 (10%), JL20 (20%), JL30 (30%) and JL40 (40%) respectively along with rice bran, soybean meal, mustard oil cake, vegetable oil and vitamin-mineral mixture. The feed with 20% of jute leaves (JL20) showed significantly (P<0.05) higher net weight gain, specific growth rate, protein efficiency ratio and daily growth coefficient. The feed conversion ratio was lower (P<0.05) in JL20. The carcass composition revealed that carcass protein and lipid content was significantly (P<0.05) higher in JL20. It may be concluded that jute leaf powder can be incorporated in the feed of rohu fingerlings up to 20%.

Effect of Plant Based Feed Attractants on Growth of Cirrhinus mrigala Fingerlings

A 60-d experiment was conducted to study the efficacy of plant-based attractants in the feed of Cirrhinus mrigala fingerlings (av. weight 5.24±0.02g). The formulated feed contained mustard cake, soyabean meal, rice bran, vegetable oil, vitamin and mineral mixture with 1% feed attractants replacing rice bran. The different attractants used in feeds are: FA0 (Control), FA1 (Awbel, Cuscuta reflexa), FA2 (Kharboj, Cucumis melo), FA3 (Tambul, Zanthoxylum acanthopodium), FA4 (Chotokakla, Piper cubeba) and FA5 (Jayatri, Myristica fragrans). The net weight gain (g) was 1.05±0.15, 2.43±0.08, 1.45±0.05, 1.53±0.28, 1.50±0.02, 2.05±0.05, respectively in dietary groups Control to FA5. The growth study with different attractants revealed that the net weight gain and specific growth rate (SGR) were significantly (P 0.05) among the groups fed with different plant based feed attractants. Thus it may be concluded that out of the attractants tested in the present experiment, use of Awbel at 1% level (FA1) in the diet induced better performance in terms of growth and feed utilisation in mrigal fingerlings.

Influence of Feeding an All Plant Ingredients Containing Diet at Different Levels on Growth and Digestive Enzyme Activity of Pond Raised Indian Major Carps

A 150 days feeding experiment was conducted in Indian major carps (IMCs) in poly-culture ponds to study their growth and digestive enzymes activity in response to feeding only plant ingredients containing diet, at different levels. Twelve earthen ponds of 0.06 ha were allocated for the experiment. Carp juveniles were stocked at a ratio of 35: 35: 30 of Catla: Rohu: Mrigal with a stocking density of 3500 fish/ha. Fish were fed on an all plant ingredients containing diet at 1.0, 1.5, 2.0 and 2.5% of their biomass in each pond. Triplicate ponds were allocated under each feeding level. The final body weight and net biomass gain were significantly (P<0.05) influenced by the dietary treatments. In all the three species of carps the highest (P<0.05) growth was obtained at 2% feeding level, and thereafter the growth was plateaued. Fish grew the lowest at 1.0% feeding level. Protease, amylase and lipase activities were studied in the three parts of the gastrointestinal tract. For all the species the amylase activity was the highest (P<0.05) in anterior intestine (AI), followed by middle intestine (MI) and posterior intestine (PI). In AI of catla and rohu the protease activity was significantly higher (P<0.05) at 1% feeding level in comparison to that in other dietary treatments. In mrigal and catla the highest lipase activity was determined in AI when fed at 1% level. The digestive enzyme amylase, protease and lipase activities found maximum with 1% feeding level. The study indicated that the best growth of IMC was obtained when fed at 2% of their body weight in pond aquaculture condition.