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        검색결과 12

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Reproductive management practices play crucial roles to maximize the reproductive performance of cows, and thus contribute to farm profitability. We aimed to assess the reproductive management of cows currently practiced in the dairy farms in an urban farming system. Methods: A total of 62 dairy farms were randomly selected considering all size of farms such as small (1-5 cattle), medium (6-20 cattle) and large farms (> 20 cattle) from selected areas of Dhaka city in Bangladesh. The reproductive managementrelated parameters viz. estrus detection, breeding method, pregnancy diagnosis, dry cow and parturition management, vaccination and treatment of reproductive problems etc. were obtained in a pre-defined questionnaire during the farm visit. Results: The visual observation method was only used (100.0%; 62/62) for estrus detection irrespective of size of the farms; while farmers observed cows for estrus 4-5 times a day, but only for 20-60 seconds each time. Regardless of farm size, 89.0% (55/62) farms used artificial insemination (AI) for breeding the cows. Intriguingly, all farms (100.0%) routinely checked the cows for pregnancy at 35-40 days post-breeding using rectal palpation technique by registered veterinarian. However, only 6.5% (4/62) farms practiced dry cow management. Notably, all farms (100.0%) provided nutritional supplements (Vit D, Ca and P) during late gestation. However, proper hygiene and cleanliness during parturition was not practiced in 77.4% (48/62) farms; even though 96.7% (60/62) farms treated cows by registered veterinarian for parturition-related problems. Conclusions: While farmers used AI service for breeding and timely check their cows for pregnancy; however, they need to increase observation time (30 minutes/ observation, twice in a day: early morning and early night) for estrus detection, consider dry cow management and ensure hygienic parturition for maximizing production.
        4,000원
        2.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Processing and characterization of graphene (Gr)-reinforced aluminium alloy 7075 (AA7075) microcomposites and nanocomposites are reported in this work. Composites are fabricated by mechanical alloying process at wet conditions. The bulk composites are prepared by uniaxial die pressing to get higher densification and sintered in an inert atmosphere. Density of the nanocomposites is higher than the microcomposites due to the reduction of grain size by increased milling time. X-ray diffraction (XRD) analysis confirms graphene interaction with the AA7075 matrix lattice spaces. The effective distribution of graphene with aluminium alloy is further confirmed by the Transmission Electron Microscopy (TEM) analysis. The hardness of the composites proportionally increases with the graphene addition owing to grain refinement. Wear morphology is characterized using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Microcomposites reveal abrasive and ploughing wear mechanism of material removal from the surface. Nanocomposites show adhesive wear with delamination and particle pull-out from the material surface.
        4,300원
        3.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 μg PGF2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; double AI with 200 × 106 sperm), S200 (n = 24; single AI with 200 × 106 sperm), D100 (n = 24; double AI with 100 × 106 sperm) and S100 (n = 18; single AI with 100 × 106 sperm). Ewes were inseminated within 12 to 18 h for single AI and, within 10 to 12 h and 16 to 18 h for double AI after the onset of oestrus. The onset of oestrus ranged from 28 to 76 h (54.33 ± 1.28 h). The high percentage (29.2%) of ewes showed oestrus between 51 to 60 h. The non-return rates were highest in group D200 (56.5%) and differed significantly (p < 0.05) from group S100 (11.1%). No ewes were pregnant in group S100, and the pregnancy rates among the remaining groups did not differ. The mean gestation period was 152.8 ± 0.5 days and no difference was observed among the groups. The lambing and multiple birth rates were 100% in group D200. The single and twin lambing was highest in group D100 (33.3%) and group D200 (83.3%), respectively. Only one triplet lambing and the highest lambing size (2.2 ± 0.2) was recorded in group D200. In conclusion, double AI with 200 × 106 sperm showed comparatively most practical for achieving high pregnancy rates and lambing performances in Bangladeshi ewes under field conditions.
        4,000원
        4.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of alpha-lipoic acid (aLA) as an antioxidant that decrease the reactive oxygen species (ROS) in bovine embryonic development. Slaughterhouse derived bovine immature oocytes were collected and 4 different concentrations (0, 5, 10 and 20 mM) of aLA was supplemented in bovine in Vitro maturation (IVM) medium. After 20 hrs of IVM, maturation rates, levels of ROS and glutathione (GSH), and further embryonic development after parthenogenetic activation (PA) and in Vitro fertilization (IVF) was investigated according to aLA concentrations. Maturation rate was significantly higher in 10 mM group than other groups (80.5% vs. 62.9, 73.9, 64.2%; P<0.05). In the levels of ROS and GSH in matured oocytes as an indicator of oocyte quality, significantly better results were shown in 5 and 10 mM groups compared with other 2 groups. After IVM, significantly higher rates of blastocyst formation were shown in 10 mM groups in both of PA (27.9% vs. 18.8, 22.3, 14.2%; P<0.05) and IVF (32.6% vs. 23.9, 27.3, 16.2%; P<0.05) embryos. In addition, significantly more cell total cell number and higher inner cell mass ratio in 10 mM PA and IVP blastocysts showed developmental competence in 10 uM groups. Therefore, based on the entire data from this study, using 10 μM of aLA confirmed to be the optimal concentration for bovine oocyte maturation and embryonic development.
        4,000원
        5.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to evaluate the influencing factors that affect the reproductive performance of cows at the Monirampur upazila in Jessore district of Bangladesh. A total of 224 cows were brought to the upazila livestock hospital for artificial insemination (AI). The cows were inseminated between 12 to 18 hours from the onset of estrus and data was obtained from the owner. Out of 224 cows, 133 became pregnant and 91 were non pregnant. In this study, the overall pregnancy rate was 59.29%. Among the age variability, the highest pregnancy rate (70.27%) was at the age of 4 years old. In case of breed variation, the highest pregnancy rate was observed in local breed (69.07%) compared with other crossbred cows. Hence the breed variations significantly influence the conception rate of cows. According to the parity, we found that the pregnancy rate was increasing with their parity but decreasing after 4th parity. The highest conception rate was observed in 3rd parity (67.74%) which was significantly higher than that of heifers (Parity-0). Here we also found that the types of bull semen used for AI had no significant effect for pregnancy rate. The skills of AI technician for AI to cows were significantly affecting the pregnancy rate. However, this study is not enough for rating and comment about the reproduction performance of cows. Therefore, further extensive study is needed for rating and recommendation for the cattle up gradation at that particular area.
        4,000원
        6.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Salmonellosis is one of the life-threating diseases of goat in Bangladesh. Therefore, the present study was designed to study the prevalence of Salmonellosis, and isolation and characterizations of the Salmonella spp. from apparently healthy and diarrheic goat. A total of 47 faces samples were collected from selected place and cultured onto different prescribed medium to isolate it. In this study, 12.76% (6/47) samples were found to be positive for Salmonella spp. During culture on SS agar medium, all of the Salmonella isolates produced round, smooth, opaque, translucent and black color colonies on SS agar media. All of the isolated Salmonella spp. fermented dextrose, maltose and mannitol with production of acid and gas but did not ferment sucrose and lactose. However, these isolates had showed Indole and Voges-Proskauer test negative, Methyl-Red test positive. All of these isolates were subjected to rapid plate agglutination test with polyvalent “O” (Poly ‘O’) and polyvalent “H” (poly ‘H’) antisera where positive agglutination were observed. They were highly sensitive to ciprofloxacin, spiramycin and gentamycin; moderately sensitive to oxytetracyline, streptomycin and amoxicillin; less sensitive to sulphamethoxazole and resistant to penicillin-G. Based on the present findings, it may be concluded that the investigated Salmonella spp. from goats might be S. typhimurium, S. enteritidis, S. brandenburg, S. salford, S. newbrunswick, S. newport or S. dublin. Further study will be needed, therefore it requires further characterization using other serological and molecular techniques.
        4,000원
        7.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted among 120 different breed cows at selected areas of Sirajgonj district from March to July 2010 to compare the reproductive performance of crossbred and Desi cows at farmer’s level. The results showed that the average daily milk yield of Desi, Shahiwal × Desi, Friesian × Desi and Jersey × Desi cows was 2.3 ± 0.2, 4.9 ± 0.9, 6.0 ± 1.0 and 5.7 ± 0.9 liters, respectively. The milk yield of crossbred cows (5.5 ± 0.6 liters/day) was significantly (p<0.01) higher than Desi cows (2.3 ± 0.2 liters/day). The average age at puberty of Shahiwal × Desi, Friesian × Desi and Jersey × Desi was significantly (p<0.01) lower than that of Desi breed. The crossbred cows had significantly (p<0.01) lower pubertal age (20.4 ± 1.2) than Desi (25.9 ± 1.1). The age at first calving in Desi cows was significantly (p<0.01) higher (37.6 ± 1.1 months) than crossbred cows (31.2 ± 1.3 months). The average gestation length of Desi, Shahiwal × Desi, Friesian × Desi and Jersey × Desi was 289.9 ± 1.4, 285.0 ± 0.0, 285.0 ± 4.2 and 282.1 ± 2.4 days, respectively. It is suggested that the overall reproductive performance of Friesian × Desi, Jersey × Desi and Shahiwal × Desi cows were better than that of Desi cow.
        4,000원
        8.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A supercritical carbon dioxide (SCC) process of dispersion of multi-walled carbon nano-tubes (MWCNTs) into epoxy resin has been developed to achieve MWCNT/epoxy com-posites (CECs) with improved mechanical, thermal, and electrical properties. The synthesis of CECs has been executed at a MWCNT (phr) concentration ranging from 0.1 to 0.3 into epoxy resin (0.1 mol) at 1800 psi, 90°C, and 1500 rpm over 1 h followed by curing of the MWCNT/epoxy formulations with triethylene tetramine (15 phr). The effect of SCC treat-ment on the qualitative dispersion of MWCNTs at various concentrations into the epoxy has been investigated through spectra analyses and microscopy. The developed SCC assisted process provides a good dispersion of MWCNTs into the epoxy up to a MWCNT concentra-tion of 0.2. The effects of SCC assisted dispersion at various concentrations of MWCNTs on modificationof mechanical, thermal, dynamic mechanical thermal, and tribological proper-ties and the electrical conductivity of CECs have been investigated.
        4,000원
        9.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Alpha-tocopherol as an antioxidant acts in preservation of chilled semen by preserving cell membrane damage from lipid peroxidation. Optimum concentrations of α-tocopherol in egg yolk-citrate (EYC) extender need to be studied in crossbred bull’s semen. Different concentrations of α-tocopherol viz. 0, 1, 2, 4 and 6mg per ml of extender were used. Semen was collected once a week from four bulls used to regular collection, aged 4 to 7 years, weighing 320 to 450 kg, and with body condition score 4 to 4.5 and scrotal circumference 23 to 32 cm. Semen was evaluated routinely and sperm morphology was viewed under light microscope at ×1,000 magnification after fixing with buffered formal saline. Over 90% had normal head, acrosome, mid-piece and tail. Semen was diluted with egg-yolk-citrate extender to produce 15×106 spermatozoa/ml and 0, 1, 2, 4 and 6 mg/ml α-tocopherol were added. The semens amples were kept at 8℃. Sperm motility and viability were examined daily up to 5 days under light microscopy at ×200 magnification. Sperm viability was acceptable (≥40%) up to the 4th day with all concentrations of α-tocopherol and up to the 5th day with 2 mg/ml α-tocopherol. Sperm motility was acceptable (≥40%) up to the 3rd day irrespective of α-tocopherol concentration, and up to the 4th day with 2 mg/ml α-tocopherol. It is suggested that the lifespan of chilled semen may be extended up to 4 days by adding 2mg/ml α-tocopherol.
        4,000원
        12.
        2020.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The purpose of this study is to analyze and test the effect of financial ratios and macroeconomics on Islamic stock returns listed in Jakarta Islamic Index (JII) other than to assess whether investment risk can be an intervening variable in this study. The type of research is explanatory in nature with a quantitative descriptive approach. The data used is based on secondary sources with a sample group of 29 companies listed on JII for a 5-year period ending 31 December 2018. The data obtained were analyzed by using SEM (Structural Equation Model) with AMOS (Analysis Moment of Structural) 21 program. The results of the study show that only financial ratios affect sharia stock returns and investment risk, while the mediation test found that investment risk does not act as a mediating variable between financial ratios and macroeconomics and Islamic stock return. These findings indicate that the role of the company’s financial health is very important. Besides affecting the rate of return obtained, the company’s financial health can also reflect the level of risk that investors will accept in the future. By improving financial performance properly, a company will have a positive impact on various interested parties and minimize the level of investor losses.