An evaluation of radiography in studies of gastric evacuation in African catfish fingerlings     

Mostafa A.R. Hossain  Graham S. Haylor  Malcolm C.M. Beveridge 《Aquaculture International》1998,6(5):379-385

Groups of 3–4 g African catfish (Clarias gariepinus Burchell, 1822; Family: Clariidae) were offered feeds of two types in three combinations: feed with a radio-opaque marker (Ballotini, 0.16–0.25 mm), feed without marker and a 50:50 mixture of marked and unmarked feeds. Stomach contents were estimated by X-radiography and gastrectomy just after meal termination and at different time intervals (4, 8, 12, 16, 20, 24, 32, 40 and 48 h). There were no significant differences among treatment groups confirming that there was no effect of the marker on feed preference and evacuation rate. Estimations of gastric evacuation rate calculated from gastrectomy and by X-ray sampling were not significantly different. Therefore, gastric evacuation rate of African catfish can be accurately estimated by feeding marked feed and then using X-radiography to monitor feed passage through the gut. © Rapid Science Ltd. 1998  相似文献   

Quantitative estimation of maximum daily feed intake of African catfish, Clarias gariepinus Burchell, fingerlings using radiography     

M.A.R. Hossain  G.S. Haylor  & M.C.M. Beveridge 《Aquaculture Nutrition》1998,4(3):175-182

Gastric evacuation rate, return of appetite and satiation time of African catfish, Clarias gariepinus Burchell 1822, fingerlings, fed with a commercial pelleted feed, were determined under experimental conditions. The gastric evacuation rate was described by an exponential function, which was found to be inversely related to the rate of ingestion (return of appetite). Satiation time remained constant over the experimental period. Based on these data the authors estimated maximum daily ration in relation to feeding schedule and feeding frequency for C. gariepinus fingerlings.  相似文献   

Growth,nutrient utilization,oxidative condition,and element composition of juvenile red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> fed with fermented soybean meal and scallop by-product blend as fishmeal replacement     

Md. Abdul Kader  Shunsuke Koshio  Manabu Ishikawa  Saichiro Yokoyama  Mahbuba Bulbul  Yuki Honda  Roger Edward Mamauag  Asda Laining 《Fisheries Science》2011,77(1):119-128

A feeding trial was conducted to evaluate the effect of fermented soybean meal and scallop by-product blend (3:2) (FP) on the performance of juvenile red sea bream. Five isocaloric diets were prepared by replacing 0% (FP0), 15% (FP15), 30% (FP30), 45% (FP45), and 60% (FP60) fishmeal (FM) protein with FP, respectively. Triplicate groups of fish (initial mean weight 2.83 g) were fed the test diets for 45 days in a flowthrough seawater system. The results demonstrated that growth rates of fish fed FP0, FP15, and FP30 were similar, and significantly higher (P < 0.05) than those of FP45 and FP60. Nutrient utilization was significantly lower in FP60, with no differences found among the other groups. Dietary heavy-metal contents were affected by inclusion of FP, impacting on whole-body heavy-metal contents. In terms of oxidative stress, fish fed the FP30 diet were in the best condition, since this fish group showed the least oxidative-stressed condition as well as the highest tolerance against oxidation. In conclusion, the approach of utilizing this fermented mixture is promising and it could replace at least 30% FM protein in red sea bream diet without negative effects on performance, body composition or health of fish.  相似文献   

Microsatellite and mitochondrial DNA analyses reveal no genetic difference between two pufferfish species torafugu <Emphasis Type="Italic">Takifugu rubripes</Emphasis> and karasu <Emphasis Type="Italic">T. chinensis</Emphasis>     

Md. Shaheed Reza  Shigeharu Kinoshita  Satoshi Furukawa  Toshitaka Mochizuki  Shugo Watabe 《Fisheries Science》2011,77(1):59-67

It has been reported that the nucleotide sequences of the mitochondrial and nuclear genes of Takifugu pufferfish torafugu T. rubripes and karasu T. chinensis show 99–100% sequence identity, indicating a very close relationship between the two species. To further investigate this genetic relationship, we compared genetic variation at four microsatellite loci and at the mitochondrial control region (CR) (561 bp) between groups of T. rubripes caught at two locations [TrG, caught in the Genkai Sea off Tsushima Island in 2003 (n = 50); TrS, caught in the Suwo Sea off Kita-Kyushu in 2008 (n = 50)] and T. chinensis caught at one location (TcK, caught off the east coast of Korea in 2004; n = 50). Analyses using microsatellite loci showed that genetic diversity index values of the TrG, TrS and TcK groups were 0.9505, 0.9350 and 0.9335, respectively, while values of genetic distance and genetic differentiation between TrG and TcK (0.0543 and 0.0189, respectively) were smaller than those between TrG and TrS (0.0857 and 0.0194, respectively). Analyses using CR for the same specimens showed that genetic distances were consistent with those obtained using microsatellite loci. These results, together with our previous observations, suggest that T. rubripes and T. chinensis are very closely related and possibly can be regarded as the same species.  相似文献   

Effects of supplementary feeds with different protein levels on growth and economic performances of Nile tilapia (Oreochromis niloticus) cultured in a rain-fed rice–fish ecosystem     

M. A. R. Mridha  M. A. Hossain  M. Nahiduzzaman  M. S. Uddin 《Journal Of Applied Aquaculture》2017,29(2):152-166

This study investigated the effects of supplementary feeds with different crude protein (CP) levels on the growth and economic performances of sex-reversed Nile tilapia (Oreochromis niloticus) reared in a rain-fed rice–fish ecosystem for a period of 120 days. There were four treatments—namely, traditional feed (21% CP), formulated feed (26% CP), commercial feed (30% CP), and control (no feed was used)—with three replicates per treatment. Fish (30.04 g) were stocked in ditches at a rate of 0.5 fish m^?2 considering the total area and fed one of the tested feeds twice daily at the rate of 2%–5% of body weight. Water-quality parameters of the ditches were monitored fortnightly, and these parameters were found suitable for fish farming. Organic matter, total nitrogen, and available phosphorous in soil were increased significantly (P < 0.05) in the feed treatments after fish cultivation. Highly significant weight gain and SGR were observed with fish fed the commercial feed as compared with other treatments. The highest benefit-cost ratio (2.15) was found in the control, followed by formulated feed (1.90), but in the case of numerical net return, it was the opposite. However, commercial feed showed the lowest benefit-cost ratio (1.67) due to higher feed cost than other supplementary feeds. Therefore, this study suggests that fish fed with a formulated feed (26% CP) produced significantly higher net economic return in the rice–fish farming system.  相似文献   

Growth and economic analysis of freshwater prawn,Macrobrachium rosenbergii (de Man), produced with feeds substituting sunflower cake for fish meal,soya bean meal and mustard oil cake          下载免费PDF全文

Mohammad Mokarrom Hossain  Subhash Chandra Chakraborty 《Aquaculture Research》2017,48(10):5418-5429

A feeding trial with Macrobrachium rosenbergii was carried out to test the effectiveness of sunflower cake (SFC) as a replacement for conventional protein sources. Four isonitrogenous (~30% crude protein) and isocaloric (388–402 kcal) diets were formulated. Diet‐1 was a control made with conventional ingredients including fish meal, soya bean meal and mustard oil cake. Diet‐2, Diet‐3 and Diet‐4 were made with 30%, 40% and 50% SFC, respectively, replacing the usual protein sources used in Diet‐1. After 100 days, diets with SFC inclusion showed favourable growth and economic performance trends compared to control diet‐1, but without significant differences (p > .05). Better production (572.89 ± 62.99 kg/ha) was observed with Diet‐4 followed by Diet‐2, Diet‐3 and Diet‐1. Diet‐4 revealed the best feed conversion ratio (2.56 ± 0.24), specific growth rate (1.18 ± 0.05) and protein efficiency ratio (1.14 ± 0.10) among these diets. Whole carcass composition analysis revealed highest crude protein (18.19%) and lipid (4.43%) content in prawns fed Diet‐3 followed by Diet‐4. Highest total income, gross margin and benefit cost ratio (BCR) per hectare from prawns were US$5,759, US$2,623 and 1.84, respectively, found in Diet‐4. This study demonstrates that 30%–50% inclusion of SFC has favourable impacts on productivity and profitability compared with controls, with 50% SFC inclusion as the most cost‐effective diet for prawns without apparent compromise in growth, flesh quality or economics. The performances of the diets suggest that SFC may be a suitable substitute for fishmeal, soya bean meal and mustard oil cake in prawn feed. The effectiveness of higher SFC concentrations should also be investigated.  相似文献   

Analyses of factors affecting dry matter intake of lactating dairy cows   总被引：1，自引：0，他引：1  

Md. Arifur Rahman MAZUMDER  Hajime KUMAGAI 《Animal Science Journal》2006,77(1):53-62

An experiment was conducted to analyze feed, climate and animal factors affecting dry matter intake (DMI) in lactating dairy cows. Sixteen lactating Holstein cows, with parity from 1 to 6, were assigned to a feeding trial for 2 years, comprising 31 lactations. The animals were fed Italian ryegrass silage, oat hay, alfalfa hay, beet pulp and three types of concentrate. The data, pooled and classified by stage of lactation, season of lactation and parity were analyzed by stepwise multiple regression to determine the nature and extent of factors affecting DMI. A total of 45 prediction equations for DMI were derived. Energy‐corrected milk yield or milk yield was selected as the primary factor of DMI in all the equations in which the ratio of contribution (R²) varied from 0.26 to 0.67. The dietary concentration of organic cell wall, crude fiber, crude protein, organic b fraction, forage to concentrate ratio, average ambient temperature and temperature–humidity index were selected as the secondary factors affecting DMI for pooled data, late lactation (251–350 days of lactation), summer (June–August), spring (March–May), ≥4th lactation, autumn (September–November) and 3rd lactation, respectively, and improved R² up to 0.77. Except for an impact of bodyweight in several equations, feed and climatic factors significantly improved prediction equations effectively for data classified in different ways. To estimate DMI accurately in lactating dairy cows, feed and climatic factors should be considered for specific conditions.  相似文献   

Two-year surveillance of tilapia lake virus (TiLV) reveals its wide circulation in tilapia farms and hatcheries from multiple districts of Bangladesh     

Partho Pratim Debnath  Jerome Delamare-Deboutteville  Mona Dverdal Jansen  Kornsunee Phiwsaiya  Afsana Dalia  Md. Abir Hasan  Saengchan Senapin  Chadag Vishnumurthy Mohan  Ha Thanh Dong  Channarong Rodkhum 《Journal of fish diseases》2020,43(11):1381-1389

Tilapia lake virus (TiLV) is an emerging pathogen in aquaculture, reportedly affecting farmed tilapia in 16 countries across multiple continents. Following an early warning in 2017 that TiLV might be widespread, we executed a surveillance programme on tilapia grow-out farms and hatcheries from 10 districts of Bangladesh in 2017 and 2019. Among farms experiencing unusual mortality, eight out of 11 farms tested positive for TiLV in 2017, and two out of seven tested positive in 2019. Investigation of asymptomatic broodstock collected from 16 tilapia hatcheries revealed that six hatcheries tested positive for TiLV. Representative samples subjected to histopathology confirmed pathognomonic lesions of syncytial hepatitis. We recovered three complete genomes of TiLV from infected fish, one from 2017 and two from 2019. Phylogenetic analyses based on both the concatenated coding sequences of 10 segments and only segment 1 consistently revealed that Bangladeshi TiLV isolates formed a unique cluster within Thai clade, suggesting a close genetic relation. In summary, this study revealed the circulation of TiLV in 10 farms and six hatcheries located in eight districts of Bangladesh. We recommend continuing TiLV-targeted surveillance efforts to identify contaminated sources to minimize the countrywide spread and severity of TiLV infection.  相似文献   

Evaluation of limb autotomy as a promising strategy to improve production performances of mud crab (Scylla olivacea) in the soft‐shell farming system     

Mohammad Redwanur Rahman  Md. Asaduzzaman  Md. Mahiuddin Zahangir  SM Rashadul Islam  Sk Ahmad‐Al Nahid  Durin Akter Jahan  Yahia Mahmud  Mohammed Nurul Absar Khan 《Aquaculture Research》2020,51(6):2555-2572

Soft‐shell crab, a newly moulted crab having non‐calcified and hydrated soft exoskeleton, farming has been increasing tremendously in recent years throughout the world due to its high market price and consumer preferences. However, high aggressiveness and cannibalistic behaviour of mud crab limit its culture to an individual chamber system which ultimately makes the soft‐shell mud crab farming space and labour‐intensive. Therefore, the aim of this study was to improve the efficiency of soft‐shell crab production by autotomy of the claw and/or walking legs to reduce the moulting duration and intensify the culture system through double stocking in the existing individual chamber culture system. To achieve our objectives, a series of experiment were conducted at both indoor and on‐farm levels by removing the claw and/or walking legs of Scylla olivacea for two consecutive moulting cycles. Results showed that both claw ablation significantly (p < .01) shortened the moulting duration and increased the carapace width, weight gain, specific growth rate, feeding efficiency and yield parameter compared to the non‐ablated crabs more prominently at 1st moulting than the 2nd moulting in both indoor and on‐farm trials. Ablation of all walking legs while keeping the claw intact did not significantly influence (p > .05) the moulting duration and carapace width, but significantly (p < .01) improved the specific growth rate, weight gain, feeding efficiency and yield parameters at 1st moulting compared to the non‐ablation and unilateral three walking leg ablation groups. However, ablation of all appendages (both claw and walking legs) showed significant (p < .01) improvements of carapace width, weight gain, specific growth rate, feeding efficiency and yield parameters, and shortened the moulting duration up to 23 days from 34 days during 1st moulting and up to 27 days from 40 days at 2nd moulting. The survivals of different autotomized mud crabs were statistically non‐significant (p > .05) to the non‐autotomized crabs in various indoor and on‐farm trials. Besides improving the production performances, ablation of bilateral claw and all appendages allowed to double the stocking density in the existing individual chamber‐based soft‐shell crab farming that enhanced the production about threefold higher than the existing individual chamber‐based culture system. Finally, our results suggest that autotomy could be a promising technology for the commercial farming of soft‐shell mud crab in near future.  相似文献   

Impact of Wall Material on the Physiochemical Properties and Oxidative Stability of Microencapsulated Spray Dried Silver Carp Oil     

Tazbidul Nawas  Md Shofiul Azam  Abuubakar Hassan Ramadhan  Yanshun Xu 《Journal Of Aquatic Food Product Technology》2019,28(1):49-63

This study aimed to microencapsulate silver carp oil by spray drying with different combinations of wall materials (gum Arabic, modified starch Hi-cap, maltodextrin, and inulin) and evaluate the effects of these combinations on the physiochemical and oxidative stability of the microcapsules. Feed emulsions were also investigated prior to spray drying. Modified starch-based microcapsules had higher encapsulation efficiency (91.22-92.78%) and yield (87.41-92.15%), excellent solubility (91.85-93.67%), good particle size (301.20-407.73 d.nm), color, and powder morphology. The presence of inulin reduced agglomeration in powders. All the powders exhibited good protection against lipid oxidation during 2 months of storage, whereas the modified starch and inulin combination provided the best stability.  相似文献