Kedar Nath Mohanta

Beneficial effects of dietary probiotics mixture on hemato-immunology and cell apoptosis of Labeo rohita fingerlings reared at higher water temperatures.

Probiotics play an important role in growth increment, immune enhancement and stress mitigation in fish. Increasing temperature is a major concern in present aquaculture practices as it markedly deteriorates the health condition and reduces the growth in fish. In order to explore the possibilities of using probiotics as a counter measure for temperature associated problems, a 30 days feeding trial was conducted to study the hemato-immunological and apoptosis response of Labeo rohita (8.3±0.4 g) reared at different water temperatures, fed with or without dietary supplementation of a probiotic mixture (PM) consisting of Bacillus subtilis, Lactococcus lactis and Saccharomyces cerevisiae) (1011 cfu kg−1). Three hundred and sixty fish were randomly distributed into eight treatment groups in triplicates, namely, T1(28°C+BF(Basal feed)+PM), T2(31°C+BF+PM), T3(34°C+BF+PM), T4(37°C+BF+PM), T5(28°C+BF), T6(31°C+BF), T7(34°C+BF) and T8(37°C+BF). A significant increase (P<0.01) in weight gain percentage was observed in the probiotic fed fish even when reared at higher water temperature (34–37°C). Respiratory burst assay, blood glucose, erythrocyte count, total serum protein, albumin, alkaline phosphatase and acid phosphatase were significantly higher (P<0.01) in the probiotic fed groups compared to the non-probiotic fed groups. A significant (P<0.01) effect of rearing temperature and dietary probiotic mixture on serum myeloperoxidase activity, HSP70 level and immunoglobulin production was observed. Degree of apoptosis in different tissues was also significantly reduced in probiotic-supplemented groups. Hence, the present results show that a dietary PM could be beneficial in enhancing the immune status of the fish and also help in combating the stress caused to the organism by higher rearing water temperature.

Evaluation of Different Animal Protein Sources in Formulating the Diets for Blue Gourami, Trichogaster Trichopterus Fingerlings

Based on the nutrient requirement of blue gourami, Trichogaster trichopterus fingerlings as reported earlier, nine experimental diets with 350 g protein, 80-100 g lipid and 16-17 MJ digestible energy/kg diet were formulated using snail meat (D-1), freshwater fish processing waste (D-2), surimi by-product (D-3), chicken offal (D-4), earthworm (D-5), squid (D-6), mussel (T-7), chicken liver (T-8) and lean prawn (T-9) as major protein source in addition to fish meal and peanut oil cake and fed ad libitum to the fish (3.54 ± 0.02 g) for a period of 45 days. Twenty seven indoor circular fiber-reinforced plastic tanks with 200 L of water were used for rearing the fish. At the end of the experiment it was found that the fish fed squid meal Diet (D-6) had the best results in terms of weight gain, food conversion ratio (FCR), specific growth rate (SGR) and protein efficiency ratio (PER). However, the freshwater fish processing waste (D-2) and surimi by-product (D-3) diets had almost similar (p>0.05) growth and dietary performance as that of squid, mussel, chicken liver and lean prawn meal diets and therefore, both these fish processing waste and surimi by-product could be used as non-conventional protein sources in formulating the nutritionally balanced cost-effective diets for blue gourami.

Potential of earthworm (Eisenia foetida) as dietary protein source for rohu (Labeo rohita) advanced fry

Abstract Earthworm, a non-conventional protein source with 520–530 g protein kg−1 on dry matter basis was used in three forms viz. (i) whole earthworm (ii) earthworm custard, and (iii) pelleted earthworm diet to prepare three iso-nitrogenous (500 g protein kg−1 diet) and iso-caloric (17.0 MJ kg−1 diet) experimental diets. The formulated diets were fed ad libitum twice daily to Labeo rohita advanced fry (0.71 ± 0.04 g) in triplicates for a period of 35 days. In each replicate, 10 fish were stocked. The 300 L fiberglass-reinforced plastic tanks containing 100 L of water with the provision of continuous aeration were used for rearing the fish. At the end of experiment, the weight gain (g), food conversion ratio, specific growth rate, protein efficiency ratio, protein retention efficiency (%), and energy retention efficiency (%) of fish fed pelleted earthworm diet (2.19, 1.58, 4.21, 1.26, 23.0, and 18.6, respectively) was significantly better (p < 0.05) than the corresponding values of whole earthworm (1.53, 2.30, 3.38, 0.84, 14.34, and 11.93, respectively) and earthworm custard (0.94, 3.18, 2.42, 0.62, 10.50, and 8.21, respectively) fed diets. The experiment results indicated that the pelleted earthworm diet could be used in rearing of rohu advanced fry.