Aquatic fern Azolla pinnata comprises significant high food value with a good proportion of protein, vitamins, and minerals. This study was carried out to examine the effect of fresh A. pinnata as a substitution of commercial fish feed (CFF) for Thai silver barb Barbonymus gonionotus. Post fingerlings of B. gonionotus were reared in five treatments, labeled T 1 to T 5 , by substituting 0%, 25%, 50%, 75%, and 100% protein of CFF with A. pinnata protein (dry matter basis) respectively for 56 days. The specific growth rate, net production rate, protein efficiency ratio, proximate composition, and overall conditions of fish were not significantly varied between the fish reared completely with CFF and 25% substitution with A. pinnata. However, a significantly higher profit rate (431.49 USD ha −1 56 day −1 ) was calculated for fish reared in T 2 than other treatments. In contrast, there was a significant reduction of growth and other parameters of the fish that were observed in the case where more than 25% CFF was substituted with A. pinnata. The poorest performance was observed in fish fed completely with A. pinnata, at T 5 . Based on the results, 25% of CFF of Thai silver barb could be substituted with fresh A. pinnata without significantly lowering their growth and product quality and could contribute significant to a higher profit margin.

The present study was conducted to reveal the present scenario, problems and the prospect of fish farming of Gazipur Sadar upazila Bangladesh. The primary data were collected through field survey, questionnaire interview and focus group discussion from the fish farmers of several villages and urban areas of the upazila. Secondary data were collected from the Department of Fisheries and aquaculture extension section. Gazipur Sadar upazila has 14462.42 ha potential fisheries resources of which floodplains, seasonal water bodies, and ponds comprise 71.01%, 13.04%, and 8.57%, respectively. The total fish production of the upazila in 2016-17 was 14492.7 MT, 27% of the Gazipur district. The highest fish production of 5436 MT and 4.39 MT/ha/year came from the pond sector. Among different pond culture systems, the semi-intensive system had the highest fish production output (2826 MT). Exotic carps were the highest produced fish in the ponds. However, in spite of comprising a huge proportion of seasonal floodplains the fish production from this sector was only 0.42 MT/ha/year in 2016-2017. This indicates the poor utilization of inland open water resources for fish production in the study area. The major areas were identified to improve the existing pond fish farming situation were access to low-interest loan, quality seed, supply of advanced technologies, need-based training, and marketing facilities. Along with improving the pond fish farming, community-based fisheries management and some aquaculture initiatives on private own seasonal floodplains should be taken on a priority basis to improve open water management and to flourish inland fish production in the study area.Progressive Agriculture 29 (1): 53-63, 2018

Acridids could be an alternative nonconventional protein source for livestock industries like poultry farms. For a high acridid biomass production, selection of acridid species along with their suitable food plants is essential. The present experiment was conducted by rearing of two common Indian acridids, Oxya hyla and Spathosternum prasiniferum, to estimate which one could produce higher annual biomass when fed on three food plants, Dactyloctenium aegyptium, Brachiaria mutica and Cynodon dactylon, to determine the most favorable food plant. Fecundity, fertility, nymphal mortality and sex ratio of both acridid species fed with three different plants were estimated for the annual biomass production in terms of number. Annual biomass production in terms of wet weight, dry weight and energy content were also estimated. Among the two acridid species, O. hyla showed higher values for fecundity, fertility and both wet and dry body weight; and lower values for nymphal mortality in all the three food plant fed sets. Among the three food plants, B. mutica was found to be the most suitable for annual biomass production of both acridids. It was concluded that mass rearing of O. hyla fed on B. mutica could yield a high annual biomass in acridid farms.Additional key words: acridid farm; Brachiaria mutica; fecundity; mass rearing; Oxya hyla. ResumenProducción de biomasa anual de dos acrídidos (Orthoptera: Acrididae) como alimento alternativo para aves de corralLos acrídidos podrían ser una fuente de proteínas no convencional alternativa para las granjas de aves de corral. Para una producción masiva de biomasa de acrídidos, es esencial seleccionar las especies adecuadas, junto con las plantas que los alimenten adecuadamente. Se llevó a cabo un experimento para criar dos acrídidos comunes en la India, Oxya hyla y Spathosternum prasiniferum y estimar cuál de ellos puede producir una mayor biomasa anual cuando se alimentan de tres plantas, Dactyloctenium aegyptium, Brachiaria mutica y Cynodon dactylon, determinando cual de ellas es el alimento más favorable. Para la producción anual de biomasa, en términos de número, se estimaron las tasas de fecundidad, fertilidad, mortalidad de ninfas y el sexo de ambas especies de acrídidos alimentados con las tres diferentes plantas. También se estimaron la producción de biomasa anual, en términos de peso húmedo y seco, y el contenido de energía. Entre las dos especies, O. hyla mostró valores más altos de fecundidad, fertilidad y peso corporal, tanto húmedo como seco, y valores más bajos de mortalidad de ninfas para las tres plantas. Entre las tres plantas utilizadas como alimento, B. mutica fue la más adecuada para la producción anual de biomasa para ambos acrídidos. Se concluye que la cría masiva de O. hyla alimentándose de B. mutica puede producir una gran biomasa anual en las granjas de acrídidos.

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Nutrient composition of the grasshoppers Oxya hyla hyla showed that they are a rich nutrient source containing 687.7 g protein/kg of dry body weight. Their antinutrient values fell within nutritionally acceptable values of the poultry bird Coturnix japonica japonica (Japanese quail). The most required essential amino acids and fatty acids were also present in sufficient amount. For feeding trial nine diets were formulated on an equal crude protein (230 g/kg) basis with grasshopper meal, fish meal, and soybean meal. Three sets of diets with grasshopper meal were prepared with 50 g/kg, 100 g/kg, and 150 g/kg grasshopper of total feed. Similarly, other diet sets were prepared with fish meal and also with soybean meal. Results were compared with another group of Japanese quails fed on a reference diet that was considered as control. Two experiments were conducted with a total number of 600, seven-day-old, Japanese quails. In experiment 1 for determination of growth performance, quails were randomly distributed into ten groups of males and ten groups of females containing 30 birds each. In experiment 2 for determination of laying performance, identical ten groups were prepared in ten repetitions (2 females and 1 male in each group) from the six-week-old birds of experiment 1. Birds of diet set GM2 have gained the highest body weight (male 4.04 g/bird/day; female 5.01 g/bird/day) followed by birds of FM3 diet set (male 3.72 g/bird/day; female 4.40 g/bird/day), whereas birds of reference diet have gained 3.05 g/bird/day for male and 3.23 g/bird/day for female. Feed conversion ratio (FCR) of birds fed with GM2 was the lowest (male 3.33; female 2.97) whereas FCR of R group was higher (male 4.37; female 4.65) than grasshopper meal and fish meal based diets. Hen day production percentage was higher (72.2) in GM2 group, followed by FM3 (63.5) group. R group had lower 1st egg weight (9.0 g), weight gain (8.2 g), percentage of hen day production (41.8%), higher feed intake (33.6 g/day/bird), and age at 1st laid egg than the grasshopper meal and fish meal based diets. So growth and laying performance of the birds were significantly better in grasshopper meal and fish meal added diet fed sets than the reference diet fed group; among all the dietary groups 100 g/kg grasshopper meal added diet mostly gave significantly better results followed by 150 g/kg fish meal added diets. It was ascertained that the O. hyla hyla meal had pronounced positive response on the birds. So, the quails could be easily fed 100 g/kg grasshopper meal added diet as it was the most suitable alternative feedstuff compared to the conventional protein source based diets.

The study was designed to explore the status of fishers’ access to the common property waterbodies (CPW) and associated problems of using CPW. Three upazillas (administrative units) of the Northern region of Bangladesh were selected for the empirical study. Data were collected from fishers, non-fishers and other stakeholders through structured interview schedules, physical observation, and participatory rural appraisal (PRA). The access of poor fishers group to the CPW was very limited in the study area. The government policy of revenue collection through leasing system badly affected the fishers group as they do not have required level of capital, unity, leadership and education. A revenue oriented fisheries management system with short lease periods was found to encourage over-fishing and destructive fishing by lessees, where the lessees were noted to sweep away all the fish stock as soon as their contract ended without considering the sustainable use of resource and biodiversity. Consequently, the productivity of the CPW is declining gradually. To ensure the effective access of fishers’ group to CPW and their sustainable use, an advised long-term community based management (CBM) plan needs to be developed with the effective participation of the fishers’ groups and other stakeholders.Res. Agric., Livest. Fish.2(1): 125-133, April 2015

Five media were formulated with 0% (control, T1), 25% (T2), 50% (T3), 75% (T4) and 100% (T5) inclusion of low-cost muriate of potash (MOP)-potassium (K) replacing high-cost reagent K2SO4-K and Spirulina platensis was cultured for 18 days. Cell dry weight, optical cell density and chlorophyll-a content of S. platensis cultured in five treatments were registered at every three-day interval and economic performance was calculated to observe the effect of K2SO4-K replacement with MOP-K. The cell biomass production and chlorophyll-a content of S. platensis cultured in 25 and 50% use of MOP-K instead of K2SO4-K (T2 and T3) did not represent any significant difference with the control treatment of 100% K2SO4-K (T1). However, further addition of MOP-K in T4 and T5 significantly reduced the cell growth and pigment content of S. platensis. In addition, a significant reduction of production cost was calculated as more percentage of K2SO4- K was replaced with MOP-K.

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