Application of Biofloc Technology for the culture of Heteropneustes fossilis (Bloch) in Bangladesh: stocking density,floc volume,growth performance,and profitability     

Shamsuddin  Md  Hossain  M. Belal  Rahman  Moshiur  Kawla  Mst. Salamun  Shufol  Md. Badiul Alam  Rashid  Muhammad Mamunur  Md. Asadujjaman  Rakib  Md. Refat Jahan 《Aquaculture International》2022,30(2):1047-1070

Though Biofloc Technology is a new concept in Bangladesh, it provides advantages for improving aquaculture production in many countries, leading to achieve sustainable development goals. The objectives of this study were to determine the effects of stocking densities on the growth performance of stinging catfish (Heteropneustes fossilis) under Biofloc Technology and assess the economic prospects and business feasibilities. Fingerlings were stocked in unique 5000-L tanks with three stocking densities, i.e., 3500 fish/tank (Treatment-I), 4000 fish/tank (Treatment-II), 4500 fish/tank (Treatment-III). The treatments showed significant differences (P?<?0.05) considering the species-specific growth rate, feed conversion ratio, and protein efficiency ratio. Treatment-I had significantly ((P?<?0.05) higher final biomass (29.51 ± 0.04 kg/m³) than the other treatments. The present findings revealed that using a lower stocking density, the Biofloc Technology reduced ammonia (NH₃), nitrite (NO₂), nitrate (NO₃), TDS, and floc volume but significantly increased the dissolved oxygen. As a result, Treatment-I had generated significantly higher net income (BANGLADESHI TAKA—BDT 86,278.90) over the other treatments. Moreover, the NPV, net BCR, and RoR with 4% and 9% opportunity cost were also significantly higher in Treatment-I than other treatments. The internal rate of return (IRR) and SWOT analysis index indicates that investing in Biofloc Technology is far superior, and a stocking density of 3500 fish/tank (Treatment-I) resulted in a faster investment return.

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Molecular typing of Iranian field isolates Mycoplasma synoviae and their differentiation from the live commercial vaccine strain MS-H using vlhA gene     

Mohammad Ali Bayatzadeh  Abass Ashtari  Ali Reza Abtin  Mohammad Abdoshah 《British poultry science》2014,55(2):148-156

1. The single-copy domain of the N-terminal region of the vlhA gene of Mycoplasma synoviae was sequenced, analysed and verified and used to type Iranian field isolates of M. synoviae and the MS-H live vaccine strain. In addition, a restriction fragment length polymorphism (RFLP) method was developed to differentiate between field isolates of Iranian and MS-H vaccine strains.

2. All sequences were analysed and aligned; the percentage similarity of the DNA was calculated and dendrograms were constructed. Based on single nucleotide polymorphism (SNP) that existed in all field isolates in Iran, the PCR-RFLP method allowed the differentiation of all M. synoviae field isolates from the vaccine strain.

3. Using phylogenetic analysis, the isolates were assigned to 8 unique genotypes and, within each group, DNA had a high level of similarity.

4. DNA sequence analysis and PCR-RFLP of the amplicon based on percent similarity and evolutionary relationship appeared to be useful tools for strain differentiation whether M. synoviae clinical isolates from infected chickens were derived from the vaccine strain or wild-type strains.

5. This study confirms the potential value of strain typing for epidemiological purposes and suggests that phylogenetic studies are essential to understand the true relationships between strains.  相似文献   

Fecal carriage of multi-drug resistant and extended spectrum β-lactamases producing E. coli in household pigeons,Bangladesh     

Badrul Hasan  Kamrul Islam  Murshidul Ahsan  Zakir Hossain  Mahmudur Rashid  Bibhas Talukder  Kabir Uddin Ahmed  Björn Olsen  Mohammad Abul Kashem 《Veterinary microbiology》2014

Antibiotic resistance and ESBL constitute a risk to human and animal health. Birds residing close to humans could mirror the spectrum of human associated antibiotic resistance. Household pigeons were screened in Bangladesh to shed light on human associated, as well as, environmental antibiotic resistance. Escherichia coli from pigeons (n = 150) were tested against 11 antibiotics. 89% E. coli isolates were resistant to one or more critically important human antibiotics like ampicillin, cefadroxil, mecillinam, ciprofloxacin, gentamicin and tigecycline. No carbapenamase-producers were detected and the lower ESBL prevalence (5%) in pigeons. ESBL-producing E. coli isolates had bla_CTX-M-15 genes. Pigeons shared some bacterial clones and had bird associated sequence types like E. coli ST1408. Fecal carriage of bacteria resistance of critically important human antibiotics, together with examples of shared genotypes among pigeons, indicate the human-birds and bird to bird transmissions are important in the epidemiology of antibiotic resistance.  相似文献   

Effect of spiramycin and tulathromycin on abomasal emptying rate in milk-fed calves     

Mehdi Rashnavadi  Mohammad Nouri  Mohammad R. Haji Hajikolaei  Housain Najafzadeh  Peter D. Constable 《Canadian journal of veterinary research》2014,78(1):61-67

Impaired abomasal motility is common in cattle with abomasal disorders. The macrolide erythromycin has been demonstrated to be an effective prokinetic agent in healthy calves and in adult cattle with abomasal volvulus or left displaced abomasum. We hypothesized that 2 structurally related macrolides, spiramycin and tulathromycin, would also be effective prokinetic agents in cattle. Six milk-fed, male, Holstein-Friesian calves were administered each of the following 4 treatments: spiramycin, 75 000 IU/kg BW, IM, this dose approximates 25 mg/kg BW, IM; tulathromycin, 2.5 mg/kg BW, SC; 2 mL of 0.9% NaCl (negative control); and erythromycin, 8.8 mg/kg BW, IM (positive control). Calves were fed 2 L of cow’s milk containing acetaminophen (50 mg/kg body weight) 30 min after each treatment was administered and jugular venous blood samples were obtained periodically after the start of sucking. Abomasal emptying rate was assessed by the time to maximal plasma acetaminophen concentration. Spiramycin, tulathromycin, and the positive control erythromycin increased abomasal emptying rate compared to the negative control. We conclude that the labeled antimicrobial dose of spiramycin and tulathromycin increases the abomasal emptying rate in healthy milk-fed calves. Additional studies investigating whether spiramycin and tulathromycin exert a prokinetic effect in adult cattle with abomasal hypomotility appear indicated.  相似文献   

Herbaceous species diversity in relation to fire severity in Zagros oak forests,Iran     

Morteza Pourreza  Seyed Mohsen Hosseini  Ali Akbar Safari Sinegani  Mohammad Matinizadeh  Seyed Jalil Alavai 《林业研究》2014,25(1):113-120

Zagros forests are mainly covered byQuercus brantii L. coppices and oak sprout clumps occupy the forest area like patches. We investigated post-fire herbaceous diversity in the first growing season after fire. For this purpose neighboring burned and unburned areas were selected with the same plant species and ecological conditions. The data were collected from areas subjected to different fire severities. Overall 6 treatments were considered with respect to fire severity and the mi-crosites of inside and outside of oak sprout clumps including： unburned inside and outside of sprout clumps （Ni and No）, inside of sprout clumps that burned with high fire severity （H）, inside of sprout clumps that burned with moderate fire severity （M）, outside of sprout clumps that burned with low fire severity （OH and OM）. Different herbaceous com-position was observed in the unburned inside and outside of oak sprout clumps. The species diversity and richness were increased in treatments burned with low and moderate fire severity. However, in treatment burned with high fire severity （H）, herbaceous cover was reduced, even-ness was increased, and richness and diversity were not significantly changed. We concluded that besides the microsites conditions in forest, fire severity is an inseparable part of the ecological effect of fire on her-baceous composition.  相似文献   

Growth, reproductive performance, muscle and egg composition in grass carp, Ctenopharyngodon idella (Valenciennes), fed hydrilla or formulated diets with varying protein levels   总被引：1，自引：0，他引：1  

Mohammad Afzal Khan  Ahmad Khalil Jafri  & Narendra Kumar Chadha 《Aquaculture Research》2004,35(13):1277-1285

Growth, reproductive performance, muscle and egg composition were investigated in grass carp, Ctenopharyngodon idella (Valenciennnes), fed hydrilla or formulated diets with varying protein levels. Five experimental diets, with varying levels (20%, 25%, 30%, 35% and 40%) of crude protein (CP), were used. One of the fish groups was fed hydrilla. Fish (44.1±0.3 cm; 913±9 g) were stocked (20 tank^?1) in outdoor concrete tanks (20 × 10 × 1.5 m) in duplicate, and fed to satiation, twice daily, at 09:00 and 17:00 hours for the experimental duration of 360 days. High (P<0.05) weight gain was recorded in fish fed 30% and 35% CP diets. However, values for gonadosomatic index (GSI), egg diameter, relative fecundity (eggs kg^?1 body weight), fertilizability and hatchability (%) were comparable (P>0.05) in fish at ≥25% of dietary protein intake. Hydrilla‐fed fish exhibited lower (P<0.05) values for the measured parameters. Crude protein content in muscle increased with dietary protein level. Highest (P<0.05) muscle protein was obtained in fish fed 35% CP diet. Muscle fat was comparable (P>0.05) among fish receiving formulated diets. Ash content was not significantly (P>0.05) different among fish of different dietary groups. Moisture content in fish fed formulated diets, with the exception of 20% CP diet, did not vary significantly (P>0.05). Eggs of fish fed formulated diets contained higher CP and fat contents than those of hydrilla‐fed fish. High (P<0.05) moisture content was noted in the eggs of hydrilla‐fed fish. Ctenopharyngodon idella fed formulated diet, with a minimum of 25% CP, showed better reproductive performance than those fed hydrilla.  相似文献   

Karyological analysis of endangered Caspian salmon, Salmo trutta caspius (Kessler, 1877)     

Mohammad Reza Kalbassi  Salar Dorafshan  Tahereh Tavakolian  Mahmoud Khazab  & Hosein Abdolhay 《Aquaculture Research》2006,37(13):1341-1347

The karyotype and chromosomal characteristics of endangered Caspian salmon, Salmo trutta caspius, in the southern part of the Caspian Sea were investigated. From the total of 60 mitotic metaphases achieved from 15 individuals, 15, 9 and 36 metaphases were with the mode <76, 76 and 80 representing 25%, 15% and 60% of metaphases respectively. So, the most common pattern of chromosome number was 80 (36 metaphases, 60%) and the number of diploid chromosomes was thus confirmed as (2n=80) of this subspecies. The karyotype consists of seven metacentric, five submetacentric and 28 telocentric pairs. The karyological parameters of the Caspian salmon, the centromic index, arm ratio, relative length and length variation range of chromosomes, were 0–0.5, 1–∞, 0.011–0.045 and 0.507–2.028 μm respectively. The total length of chromosomes in haploid series was 44.776 μm and fundamental number of chromosome arms was 104. This study may provide the first knowledge on chromosome analysis in Caspian salmon and add basic information useful for its chromosomal manipulations.  相似文献   

Rates of inbreeding and genetic diversity in Iranian Holstein Cattle     

Mohsen Dadar  Saeid Ansari Mahyari  Mohammad Rokouei  Mohammd Ali Edriss 《Animal Science Journal》2014,85(10):888-894

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in Holstein dairy cattle. The goal of this study was to estimate inbreeding levels and other measures of genetic diversity, using pedigree information from Iranian Holstein cattle. Edited pedigree included 1 048 572 animals. The average number of discrete generation equivalents and pedigree completeness index reached 13.4 and 90%, respectively. The rate of inbreeding was 0.3% per year. Effective number of founders, founder genomes, non‐founders and ancestors of animals born between 2003 and 2011 were 503, 15.6, 16.1 and 25.7, respectively. It was proven that the unequal founder contributions as well as bottlenecks and genetic drift were important reasons for the loss of genetic diversity in the population. The top 10 ancestors with the highest marginal genetic contributions to animals born between 2003 and 2011 and with the highest contributions to inbreeding were 48.20% and 63.94%, respectively. Analyses revealed that the most important cause of genetic diversity loss was genetic drift accumulated over non‐founder generations, which occurred due to small effective population size. Therefore, it seems that managing selection and mating decisions are controlling future co‐ancestry and inbreeding, which would lead to better handling of the effective population size.  相似文献   

Protein Requirements of the Freshwater Prawn Macrobrachium rosenbergii Evaluated by the Factorial Method     

Shin-Ichi  Teshima  Shunsuke  Koshio  Manabu  Ishikawa Md. Shah  Alam Luis Hector  Hernandez Hernandez 《Journal of the World Aquaculture Society》2006,37(2):145-153

The dietary protein requirement of the freshwater prawn Macrobrachium rosenbergii to obtain the maximum body protein retention was assessed by the estimated protein needed daily for maintenance (M) and body protein increment (G). The body protein increment was estimated by quantifying body nitrogen increments when the prawn was fed high‐protein diets composed primarily of casein. The protein required for maintenance was estimated by regressing weight gains in feeding experiments using graded dietary levels of casein. The true daily retention (R) or increase in body protein of the prawn corresponds to the sum of M and G. The values of M, G, and R determined in the present study were 3.86, 0.24, and 4.10 g/kg body weight/d, respectively. On the basis of the daily body protein increment and the net protein utilization of casein (58%), dietary protein requirement of the juvenile M. rosenbergii for maximum body protein retention was suggested to be about 7.1 g/kg body weight/d.  相似文献   

Observations on the reproductive performance of three mouth-brooding tilapia species in low-salinity underground water     

Mohammad T Ridha 《Aquaculture Research》2004,35(11):1031-1038

The reproductive performance and seed production of three mouth‐brooding tilapia species, Oreochromis spilurus (Günther), Oreochromis aureus (Steindachner) and Taiwanese red tilapia hybrid, were compared in low‐salinity underground water (3–5 g L^?1) to select species with the highest reproductive rate. Two‐year‐old males and females having average body weights of 454 and 259 g, respectively, were stocked in 2‐m³ fibreglass breeding tanks (two tanks per species) at 1:3 male to female sex ratio and at average density of three fish m^?2. Seeds (unhatched eggs; yolk‐sac fry and the swim‐up fry) were collected weekly for 112 days. The results showed O. spilurus to have significantly higher (P<0.05) mean spawning parameters expressed as total seed tank^?1 (84 154), seed kg female^?1 day^?1 (284), seed m^?2 day^?1 (190.3) and seed female^?1 day^?1 (76.3), than O. aureus and red tilapia. Monthly seed production in O. spilurus and red tilapia gradually increased from May, peaked in July and declined in August, while in O. aureus, it continued to decrease from May to August. In this study, the observed production levels of seed in O. spilurus were among the highest levels reported for tilapia; therefore, O. spilurus could be selected as a potential candidate for mass seed production in commercial tilapia hatcheries.  相似文献