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31.
Journal of Crop Science and Biotechnology - Understanding genetic architecture of a crop germplasm is necessary for designing a successful breeding program. Herein, we evaluated a large collection...  相似文献   
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The objective of this study was to determine the effect of two different freezing rate then thaw‐aging regimens on the quality attributes of lamb loins. The loins were randomly allocated to one of five different freezing/thawing/aging regimes: fast‐(FF1A0) and slow‐(SF1A0) frozen only; fast‐(FF1A2) and slow‐(SF1A2) frozen then thaw‐aged for 14 days; aged for 14 days never frozen (A2). FF1A2 samples had a significantly higher water‐holding capacity compared to the slow frozen regardless of further aging periods. FF1A2 samples had lower (p < 0.05) shear force values than A2 and higher (p < 0.05) water‐holding capacity compared to the SF1A2. Fast freezing resulted in more intracellular cryo‐damage, whereas slow freezing resulted in extracellular cryo‐damage. FF1A0 and SF1A0 samples had lower (p < 0.05) myofibrillar proteins degradation. This study demonstrated that fast freezing then thaw‐aging can result in an improved water‐holding capacity and tenderness through the minimization of extracellular ice crystal formation, reduction in purge and drip losses, and improved proteolysis in thawed lamb.  相似文献   
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The objective of this study was to create various pH/temp decline rates in hot‐boned bull beef M. longissimus lumborum (LL) through a combination of electrical stimulation (ES) and pre‐rigor holding temperature. The relationship between the pre‐rigor interventions, the activities of µ‐calpain and small heat shock proteins (sHSP), and the impacts on meat product quality were determined. Paired LL loins from 13 bulls were hot‐boned within 40 min of slaughter, immediately ES and subjected to various holding temperatures (5, 15, 25, and 35°C) for 3 hr. The rate of muscle pH decline, sarcomere length, shear force, and proteolysis of muscle proteins were measured. ES‐25°C had a longer sarcomere length compared to non‐electrical stimulation samples. ES‐25°C and ES‐35°C samples had lower shear force values, higher µ‐calpain activity and higher desmin, troponin‐T, and sHSP degradation. The above findings suggest that pH/temp decline rates created in hot‐boned muscle impacted muscle protein proteolysis by increasing the activity of proteases and degradation of sHSP.  相似文献   
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This study was conducted to replace soya bean meal with maggot meal at difference percentages. A total of 120 one‐day‐old broiler chicks were divided into four groups. Four diets were formulated with maggot meal to replace soya bean meal at the rate of 0%, 10%, 20% and 30% designated as A, B, C and D respectively. Feed and water were offered ad libitum during the study which lasted for 28 days. Feed intake decreased significantly in treated groups while body weight, Feed conversion ratio and dressing percentage increased significantly in group D. Apparent metabolizable energy increased significantly in the group fed 30% maggot meal; however, no significant difference was found in dry matter, crude protein, crude fibre, ether extract, ash and nitrogen free extract between the control and treated groups. The result of sensory evaluation revealed that tenderness and juiciness increased significantly in group C and B respectively. The colour and flavour were most accepted in group B and C. The results indicate that replacement of soya bean meal at the rate of 30% in broiler feed produced most favourable results.  相似文献   
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The objective of this study was to use mouse embryos as a model system to investigate the effect of co-culture of cumulus cells in Sydney IVF sequential media (Cook) on embryo development, based on the hypothesis that feeder cells in co-culture with a sequential medium could work synergistically to further improve in vitro culture conditions for mammalian preimplantation embryos. The culture systems described here were evaluated by the ability to consistently produce high blastocyst formation rates and high cell number per blastocyst. The role of embryo-to-cell contact was assessed by using Transwell inserts with transparent microporous membranes. Pronuclear embryos of ICR mice were cultured to blastocysts in Cook sequential media, with and without mouse primary cultures of cumulus cells, and with or without inserts. Blastocyst formation rates and cell numbers of in vitro developing embryos in the different culture systems were compared to each other, and to in vivo derived blastocysts. Blastocyst formation rates for Cook medium only was 27.8% (without inserts) and 32.9% (with inserts), whereas Cook-Cumulus cells in identical culture systems was significantly higher at 45.8% (without inserts, P<0.05) and 55.6% (with inserts, P<0.05). When the embryos are suspended above the bottom of the well, for Cook medium significantly lower blastocyst formation rates were observed at 4.2% compared to Cook-Cumulus cells at 17.5% (P<0.05). Mean cell numbers of blastocysts obtained in all co-culture systems were significantly higher (P<0.05) compared to those developing in culture medium only. Although the putative mechanism is as yet unexplained, the improved blastocyst formation rates and cell numbers in co-culture when there is direct contact between the embryo and the cell monolayer suggest that the close proximity between the feeder cells and embryos is in part responsible for these effects.  相似文献   
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Lumpy skin disease (LSD) is a highly infectious disease of cattle caused by a virus belonging to the Capripoxvirus genus of the family Poxviridae. The purpose of this study is to place on record the first confirmation of LSD in the Sultanate. The disease was diagnosed and confirmed using polymerase chain reaction, histopathology, transmission electron microscopy and serum neutralization testing. The epizootic occurred in 2009 involving a large number of animals and covering a wide area including Nezwa, Alqabel, Sohar, Saham and Burimi. Morbidity and mortality rates of 29.7 and 26.3 %, and 13.6 and 15.4 % were observed at Nezwa and Sohar, respectively. The clinical signs were much more severe in Holstein–Friesian cattle compared to indigenous breeds and were characterized by multiple skin nodules covering the neck, back, perineum, tail, limbs and genital organs. Affected animals also exhibited lameness, emaciation and cessation of milk production. Oedema of limbs and brisket, and superficial lymph node enlargement were highly prominent. It is not known from where the virus originated, or how it spread to the Sultanate. The disease has become endemic in the country and is liable to extend to other Gulf Cooperation Council Countries and cause a pandemic. It is of major concern to the Omani dairy industry. Due to the widespread presence of screw worm, serious economic losses can follow outbreaks.  相似文献   
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To assess the drainable surplus of an irrigated area, a methodologybased on a groundwater-balance approach was developed and appliedin Schedule I-B of the Fourth Drainage Project near Faisalabad inPakistan. To determine the seasonal net recharge in this area, anumerical groundwater model was run in inverse mode. The data inputfor the model consisted of the geometry of the aquifer system, theaquifer parameters, and historical watertable elevations. The seasonalnet recharge values, calculated from the individual recharge anddischarge components, were tuned with the results of the inversemodelling. The advantage of such an integrated approach is that allthese components are linked. The design net recharge was estimatedfrom the historical net recharge of the wettest monsoon in the studyperiod. Its rainfall recharge values were then substituted for those of adesign monsoon. In this substitution procedure, the rainfall rechargemethodology and parameters were adopted from the tuning procedure.From this design net recharge, estimates could be made of the requireddrainable surplus, with and without drainage simulation.  相似文献   
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金钱鱼(Scatophagus argus)是我国东南沿海名优养殖鱼类, 具有 XY 性别决定系统, Dmrt1 是其性别决定候选基因。金钱鱼生长具有性别二态性, 雌鱼生长快于雄鱼。目前缺乏快速鉴定金钱鱼遗传性别的分子标记, 阻碍了其性别控制育种技术的建立。本研究以公布的金钱鱼基因组数据, 在 Dmrt1 附近设计多对标记引物, 并通过 PCR 扩增验证标记的性别特异性。其中, 标记引物 Dmrt1-Marker-4-F/R 在雌鱼中仅扩增出一条 593 bp X 染色体条带, 而在雄鱼中能扩增出 593 bp 和 693 bp 两条条带, 分别来自 X 和 Y 染色体, 表明该标记为共显性标记。利用该标记检测我国南海沿岸 3 个不同地理群体 213 尾金钱鱼的遗传性别与表型性别完全一致。此外, 快速 DNA 提取试剂盒提取的片段较短 DNA 样品也可用于该对标记引物准确鉴定遗传性别。本研究建立了一种快速、准确、经济可靠的金钱鱼遗传性别鉴定方法, 将旨为促进金钱鱼性别控制育种技术的建立, 并为金钱鱼性别决定与分化机制研究提供依据。  相似文献   
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