MM Rashid, A Islam, MS Uddin and MT Hasan*
Journal of Sylhet Agricultural University, 2019, Volume 6, Number 1 and 2; Pages: 79-86
Feeding experiment was conducted for 62-days with commercial probiotic “Navio plus” to identify and quantify its effects on growth and feed utilization parameters of Asian stinging catfish (Heteropneustes fossilis). Ten (10) H. fossilis fingerlings (3.63±0.02 g) were stocked in each aquarium and 12 aquaria were divided into four groups (3 aquaria/group). Fish groups were fed without probiotic, 2, 5 and 10g / kg probiotic which was marked as T1 (control), T2, T3 and T4 (treatments), respectively. At the end of the experiment, mean final body weight (FBW) of T1, T2, T3 and T4 was 12.92±0.01, 14.05±0.01, 15.67±0.01 and 16.21±0.01 g, respectively. Similarly, mean weight gain (WG) was 255.83±0.42, 287.05±0.27, 331.68±0.27 and 346.56±0.27%, respectively. Among these results, FBW and WG in all treatments were significantly (P < 0.05) higher than control (T1), where T4 had the highest value among the treatments. Like as FBW and WG, specific growth rate was also significantly increased in all treatment groups. In case of feed utilization parameters, feed conversion ratio and feed efficiency ratio among these diet groups remain unchanged (P > 0.05). However, protein efficiency ratio in T1 (1.30±0.100) was the lowest, whereas, T4 achieved the highest value as found in FBW and WG. Therefore, tested probiotic may be used at a dose higher than its company recommended dose to get higher growth as well as more production for profitable H. fossilis aquaculture in Bangladesh
Keywords: Commercial probiotic, Aquaculture, Growth performance, Stinging catfish, Water quality
M J Islam, M N Hasan, M Kunda, M A Sultana and D Pandit
Journal of Sylhet Agricultural University, 2016, Volume 3, Number 1; Pages: 45-51
The study was conducted to evaluate the comparison of production performance and economics of different carp polyculture systems in Gangni Upazila under Meherpur district from July to November 2015. PRA tools such as questionnaire based interview, cross check interview etc. were used for primary data collection and secondary information were used to assess the performances in aquaculture activities. Forty pond fish farmers were randomly selected, among them 7 (18.0 %), 17 (42.0 %), 3 (8.0 %), 7 (18.0 %) and 6 (15.0 %) farmers were engaged with carp-mola, carp-tilapia, carp-koi, carp-shing polyculture and carp fattening, respectively. Only 23 % farmers had small ponds (5dec -15 dec), 35 % medium (16 dec-25 dec) and 40 % had large ponds (above 25 dec). The minimum water depths of 23 % ponds were within 0. 5m -1.0 m, 53 % were 1.00m-1.5 m, 17 % were 1.6m -2.0 m and 7 % were up to 2.0 m. From the survey, it was found that 14 (35.0 %) of the farmers applied supplementary/homemade feed prepared with rice bran and mustard oil cake, 17 (43.0 %) farmers used commercial feed and 9(22.0 %) farmers were depended on natural feed. Average fish production of the farmers was 6274 kg ha-1 yr-1. The calculated highest fish production 7,904 kg ha-1 yr-1 and net income was BDT 2,42,060 ha-1 yr-1, respectively in carp-tilapia polyculture system. The lowest fish production was 5,187 kg ha-1 yr-1 and net income was BDT 1,66,478 came in carp-koi polyculture system. From the result of present study, it is clear that fish production and financial benefit in carp-tilapia polyculture were higher than others. The present findings reveal that carp-tilapia polyculture system is more suitable and profitable culture system than other polyculture systems existing in Gangni upazila of Meherpur district.
Keywords: Fish farmer, aquaculture, polyculture system, carp, pond
T K Paul and M M M Alam
Journal of Sylhet Agricultural University, 2015, Volume 2, Number 1; Pages: 117-125
The study was conducted to assess the feasibility of rice-straw ash (RSA) as liming material in aquaculture through four experiments for a period of 6 month from February to July 2003. The first experiment was carried out using quick lime (CaO) as control. The second was conducted to determine the effects of RSA on mud turbidity and water quality. The third was conducted to determine the effects of RSA on water quality and growth of Nile tilapia (Oreochromis niloticus). The fourth was conducted to determine the effects of RSA on water quality. The neutralizing value and efficiency rating of RSA were about 11.02% and 30.17%, respectively, which were much lower than CaO. RSA brought total alkalinity to 227mgL-1 as CaCO3, which was much lower than CaO (1,775 mg/L as CaCO3). Total hardness increased by RSA was significantly higher than CaO (P < 0.05). Increase of pH by RSA was significantly lower than CaO (P < 0.05). RSA was not effective in removing mud turbidity. Total alkalinity was positively correlated with RSA doses. RSA raised pH value significantly at all doses compared to control. All treatments indicated that RSA released significant amount of phosphorus. RSA has potentials to be used as low-cost alternative liming material and phosphorus source for aquaculture. It is therefore recommended that RSA may be applied at the rate of 7.5 - 20 g/L-1 to maintain favourable pH, total alkalinity and total hardness in aquaculture pond. The study will contribute to increase aquaculture production through utilizing low-cost alternative liming material i.e. RSA, especially for resource-poor farmers.
Keywords: Rice-straw ash, alternative liming material, pH, aquaculture, Oreochromis niloticus