The ultra-sonication of minerals in swine feed     

Mayra A. D. Saleh  Pedro M. Padilha  Lucélia Hauptli  Dirlei A. Berto 《畜牧与生物技术杂志(英文版)》2015,6(1)

A sample preparation method based on ultrasound assisted-extraction (UAE) of Ca, Mg and P from swine feed has been described. The experiment was performed to cover the variables influencing the sonication process and, the method validation using standard reference material. Final solutions obtained upon sonication were analyzed by flame atomic absorption spectrometry (for Ca and Mg) and by UV–vis spectrophotometry (for P). The best conditions for metal extraction were as follows: sample mass: 100 mg in 20 mL 0.10 mol/L HCl, a particle size: <60 μm, sonication time: 5 cycles of 10 s and ultrasound power: 102 W. The UAE method was applied in digestibility assays in different piglet feeds and their results showed that it is highly comparable (P > 0.05) to the other methods used for such purposes, as block digestion, and offered a Ca, Mg and P method of quantification limit of 10.6, 12.4 and 14 mg/kg, respectively. The major advantages of the UAE method compared to other methods are the high treatment rate, low reagent usage in the extracts and, it does not generate toxic residues that might negatively affect human health and the environment, accompanied by good precision and accuracy.  相似文献   

Use of Vaginal Electrical Resistance to Diagnose Oestrus,Dioestrus and Early Pregnancy in Synchronized Tropically Adapted Beef Heifers     

CD Hockey  ST Norman  JM Morton  D Boothby  NJ Phillips  MR McGowan 《Reproduction in domestic animals》2010,45(4):629-636

The primary objective of this study was to determine whether a single measurement of intravaginal electrical resistance (VER), using the commercially available Ovatec^® probe, can discriminate between dioestrus and oestrus in Bos indicus females, which had been treated to synchronize oestrus. Santa Gertrudis heifers (n = 226) received one of three oestrous synchronization treatments: double PGF_2α 10 days apart, 8‐day controlled internal drug release (CIDR) treatment or CIDR pre‐synchronization + PGF_2α 10 days after CIDR removal. The heifers were inseminated within 12 h following observed oestrus, or, if not observed, at a fixed time approximately 80 h, following the last synchronization treatment. They were palpated per rectum for signs of pregnancy 9 weeks after artificial insemination (AI). Vaginal electrical resistance measurements were taken at the completion of synchronization treatments (presumed dioestrus), immediately prior to AI (oestrus), and then at 3 and 9 weeks post‐AI. Mean VER differed between presumed dioestrus and oestrus (113.7 vs 87.4, p < 0.001). The area under the receiver operating characteristics (ROC) curve was 0.925, indicating that VER was highly discriminatory between dioestrus and oestrus. Vaginal electrical resistance at time of AI was negatively associated with odds of conception when all inseminations were included in the analyses [odds ratio (OR) = 0.97; 95% CI 0.95–1.00; p = 0.018], but not when fixed time AIs were excluded (OR = 1.00; 95% CI 0.97–1.03; p = 0.982). Mean VER readings differed between pregnant and non‐pregnant animals at both 3 weeks (120.5 vs 96.7, p < 0.001) and 9 weeks (124.0 vs 100.3, p < 0.001) post‐AI. However, 3‐ and 9‐week VER measurements were not highly discriminatory between pregnancy and non‐pregnancy (area under ROC curve = 0.791 and 0.736, respectively). Mean VER at time of AI for animals diagnosed in oestrus differed between each of the oestrous synchronization treatments (84.7, 73.6 and 78.9, groups 1–3 respectively, p < 0.001). These findings suggest that measurement of VER may improve accuracy of oestrus diagnoses when selecting cattle for AI following oestrous synchronization programmes involving tropically adapted cattle.  相似文献   

Coupling ecosystem and individual‐based models to simulate the influence of environmental variability on potential growth and survival of larval sprat (Sprattus sprattus L.) in the North Sea     

UTE DAEWEL  MYRON A. PECK  WILFRIED KÜHN  MICHAEL A. ST. JOHN  IRINA ALEKSEEVA  CORINNA SCHRUM 《Fisheries Oceanography》2008,17(5):333-351

To investigate the impact of changing environmental conditions in the North Sea on the distribution and survival of early life stages of a marine fish species, we employed a suite of coupled model components: (i) an Eulerian coupled hydrodynamic/ecosystem (Nutrients, Phyto‐, Zooplankton, Detritus) model to provide both 3‐D fields of hydrographical properties, and spatially and temporally variable prey fields; (ii) a Lagrangian transport model to simulate temporal changes in cohort distribution; and (iii) an individual‐based model (IBM) to depict foraging, growth and survival of fish early life stages. In this application, the IBM was parameterized for sprat (Sprattus sprattus L.) and included non‐feeding (egg and yolk‐sac larval) stages as well as foraging and growth subroutines for feeding (post‐yolk sac) larvae. Sensitivity analyses indicated that the angle of visual acuity, assimilation efficiency and the maximum food consumption rate were the most critical intrinsic model parameters. As an example, we applied this model system for 1990 in the North Sea. Results included not only information concerning the interplay of temperature and prey availability on larval fish survival and growth but also information on mechanisms underlying larval fish aggregation within frontal zones. The good agreement between modelled and in situ estimates of sprat distribution and growth rates in the German Bight suggested that interconnecting these different models provided an expedient tool to scrutinize basic processes in fish population dynamics.  相似文献   

旋毛虫感染兔血清抗体消长规律的研究   总被引：1，自引：0，他引：1  

张北民  张惠英 《中国兽医寄生虫病》2000,8(2):16-18

应用旋毛虫肌幼虫干燥冷浸可溶性抗原与聚醛化聚苯乙烯（ＰＡＰＳ）载体微球共价交联制成快诊试剂,对旋毛虫感染兔血清进行检测,初步探明其血清抗体的消长规律。实验显示,以１６０００条肌幼虫／只经口饲喂感染１０只兔,于第７天可检出抗体,并分别于感染后第４５￣４９天先后达到抗体最高水平,然后维持一段时间（２０￣３０天左右）,以后逐渐缓缓下降。此结果与旋毛虫肌幼虫感染宿主后的生活周期相吻合。肌幼虫在肠道内发育为  相似文献   

Variations in the drift of larval cod (Gadus morhua L.) in the Baltic Sea: combining field observations and modelling     

RÜdiger Voss  Hans-Harald Hinrichsen  & Mike ST John 《Fisheries Oceanography》1999,8(3):199-211

Coupled three-dimensional (3-D) physical oceanographic modelling and field sampling programmes were carried out in May 1988 and August 1991 to investigate the potential drift of larval cod ( Gadus morhua L.) in the Bornholm Basin of the Baltic Sea. The goals were to predict the transport of cod larvae, thus aiding the identification of physical processes influencing larval retention/dispersal. Numerical simulations were performed using a 3-D eddy-resolving baroclinic model based on the Bryan–Cox–Semtner code adapted for the Baltic Sea. Within the Bornholm Basin, the model was initialized with ground truth data of physical parameters obtained on the research cruises, and all simulations were forced with actual wind data. Outside the basin, generalized hydrographic features of the Baltic Sea were utilized by incorporation of simulated hydrographic fields from previous model runs typical for the time periods considered. Larval drift was simulated either by incorporation of passive drifters, or as the initial horizontal distribution of larvae implemented into the model. Drift model simulations of larval transport agreed relatively well with field observations. The influence of variations in the vertical distribution on a smaller scale, i.e. vertical deviations of ± 6 m from the observed mean centre of mass, on the drift was examined, revealing no significant differences in the drift of larvae depending on their vertical distribution. The different wind forcing during the investigated time periods was linked to a retention situation in May 1988 and to a dispersal situation in August 1991. Finally, observed spatial distribution patterns of 1-group cod based on Baltic Young Fish Surveys (BYFS) were compared with their predicted transport in the larval phase and examined with respect to recruitment.  相似文献   

The combining power of hemoglobin for alkyl isocyanides,and the nature of the heme-heme interactions in hemoglobin     

ST GEORGE RC  PAULING L 《Science (New York, N.Y.)》1951,114(2972):629-634

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Survival of White Spot Syndrome Virus–Infected Litopenaeus vannamei Fed with Ethanol Extract of Uncaria Tomentosa          下载免费PDF全文

Osmar Tomazelli Júnior  Fernanda Kuhn  Paulo José Mendonça Padilha  Luiz R. Mota Vicente  Sergio Winckler da Costa  Bruno Corrêa da Silva  Delano Dias Schleder  Cristiano Nunes Nesi  Jacir Dal Magro  Sílvia de Lamo‐Castellví 《Journal of the World Aquaculture Society》2018,49(1):165-174

With the present project, the phytochemical composition of Uncaria tomentosa cultivated in Chapecó (Brazil) was analyzed and then the potential of using this local plant extract to protect by oral feeding virus‐infected Litopenaeus vannamei shrimp was also investigated. For this study, five treatments were tested: uninfected shrimp fed with pelleted feed (T_C), WSSV‐infected shrimp fed with pelleted feed (T₁), infected shrimp fed with pelleted feed with 1% ethanol extract of U. tomentosa (EEUT) (T₂), infected shrimp fed with pelleted feed with 2% EEUT (T₃), and infected shrimp fed pelleted feed with 4% EEUT (T₄). The chemical analysis of EEUT showed the presence of alkaloids, flavonoids, sterols, terpenes, coumarins, and tannins and also a high in vitro free radical‐scavenging activity as well as high total phenolic content. Shrimp fed with 2 and 4% EEUT (T₃ and T₄) showed a survival probability significantly higher than T₁ and T₂ treatments and no clinical symptoms of WSSV infection. Immunological assay also showed a positive phenoloxidase activity effect on shrimp fed with EEUT.  相似文献   

Low sensitivity of a test for anti‐Mullerian hormone to assess presence of ovaries in prepubertal bitches          下载免费PDF全文

JR Hill  J Wilkinson  J Mallyon  ST Anderson 《Australian veterinary journal》2018,96(9):356-359

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Generation of embryonic stem‐like cells from in vivo‐derived porcine blastocysts at a low concentration of basic fibroblast growth factor          下载免费PDF全文

NR Han  H‐Y Kim  S Baek  S‐H Lee  J Lee  E Lee  C‐K Park  ST Lee 《Reproduction in domestic animals》2018,53(1):176-185

Although basic fibroblast growth factor (bFGF) is an essential factor supporting the maintenance of porcine embryonic stem (ES) cell self‐renewal and pluripotency, its high cost has limited previous studies, and the development of a low‐cost culture system is required. For these systems, in vivo blastocysts were progressively cultured under various conditions consisting of different culture mediums and/or different feeder cell numbers at a low concentration of bFGF. As the results, the sequential culture of in vivo‐derived porcine blastocysts on 5.0 × 10⁵ mouse embryonic fibroblast (MEF) feeder cells in alpha minimum essential medium‐based medium for primary culture, on 2.5 × 10⁵ MEF feeder cells in Mixture medium for the 1st subpassage, and on 2.5 × 10⁵ MEF feeder cells in DMEM/Ham's F10‐based medium for the post‐2nd subpassage could support the establishment and maintenance of porcine ES‐like cells at the low concentration of bFGF. The established porcine ES‐like cells showed ES cell‐specific characteristics such as self‐renewal and pluripotency. We confirmed that porcine ES‐like cells could be generated from in vivo‐derived porcine blastocysts at a low concentration of bFGF.  相似文献   

Occurrence of blossom‐end rot in tomato as a function of calcium dose in the nutrient solution and air relative humidity     

Elder Antonio S. Paiva  Herminia E. Prieto Martinez  Vicente Wagner Dias Casali  Lilian Padilha 《Journal of plant nutrition》2013,36(12):2663-2670

The effects of different calcium (Ca) concentrations in the nutrient solution and of air relative humidity (RH) on the Ca levels and on the incidence of blossom‐end rot in tomato fruit cv. Jumbo were studied. The experiment was conducted in a greenhouse under hydroponic conditions using a modified Hoagland solution containing different Ca concentrations (0.2, 2.5, 5.0, 10.0, 15.0, and 20.0 mm L^‐1) which represented the different treatments. The trial was conducted in a fully randomized design with three replications, with Ca doses representing the plots and environments with high and low RH the subplots. The fruits of the second and third clusters were used, with two fruits per cluster, one maintained at high (90±5%) and the other at low (40±5%) RH. The fruits were picked after full ripening. A greater Ca accumulation was observed in fruits submitted to low RH with this accumulation occurring at all Ca levels in the solution. In the treatment with 100 mg Ca L^‐1, the plants died and did not reach fructification. The fruits of plants treated with 100 mg Ca L^‐1 and submitted to low RH had blossom‐end rot although their Ca levels were higher than those detected in the fruits of this treatment submitted to high RH. At this Ca dose, the seeds were small, malformed, and black. Our results show that fruit kept at low RH had higher Ca accumulation although the excessive water loss from tissues may lead to blossom‐end rot when low Ca doses are supplied to the plants.  相似文献