ovine

Ovine
  • 文章类型: Journal Article
    绵羊饲养员要求美国绵羊实验站(USSES)通过国家绵羊改良计划(NSIP)参与国家遗传评估。原因包括需要(1)比较工业和美国农业部(USDA)的生产率,(2)美国农业部鸡群的透明度,(3)NSIP的遗传联系,通过对行业群体进行抽样,(4)开发供公开发布的优质遗传系。作为回应,USSES开始将来自NSIP参与羊群的外部父亲纳入USSESTarghee羊群。我们的目标,根据谱系分析,是为了测试外部遗传学是否渗入羊群。谱系包括13189只平均最大世代的动物,意味着完整的世代,和平均等效完整代分别为4.2、1.8和2.6。平均世代间隔为3.1年。参考种群定义为2021年至2023年出生的羔羊(n=792)。另外两个种群被定义为当前的成熟母羊群(n=123)和当前的成熟公羊群(n=14)。整个种群的遗传保护指数平均为7.7,参考种群为25.7。整个种群的总体近亲繁殖为0.003,参考种群为0.006。近交率为每代0.0003。整个人群的平均亲缘关系为0.015,参考人群的平均亲缘关系为0.018。创始人的有效数量,祖先的有效数量,对参考人群有贡献的创始人基因组当量分别为60,39和19.1.创始人的有效数量与祖先的有效数量之比为1.5,表明存在遗传瓶颈。有效人口规模的度量范围为102至547。在外来父亲产生的704个后代中,保留了17只公羊和132只母羊用于繁殖。USSES父亲产生了299个后代,其中保留了2只公羊羔羊和51只母羊羔羊。合并外部父系导致参考人群的外部遗传学的遗传方差的累积百分比为48.8、49.1和44.2,当前成熟的母羊群,和目前成熟的公羊,分别。利益相关者的需求通过外部父亲的渗入和参与NSIP来解决,但是未来的选择实践需要进行修改,以保持羊群中至少50%的USSES核心遗传学。
    Sheep breeders requested that the U.S. Sheep Experiment Station (USSES) to participate in national genetic evaluation through the National Sheep Improvement Program (NSIP). The reasons included the need for (1) a comparison of the productivity of industry and United States Department of Agriculture (USDA) lines, (2) transparency of USDA flocks, (3) genetic ties for NSIP by sampling of industry flocks, and (4) development of premium genetic lines for public release. In response, USSES began to incorporate external sires from NSIP participating flocks into the USSES Targhee flock. Our objective, based on a pedigree analysis, was to test if introgression of external genetics into the flock was achieved. The pedigree included 13,189 animals with mean maximum generations, mean complete generations, and mean equivalent complete generations of 4.2, 1.8, and 2.6, respectively. The mean generation interval was 3.1 yr. The reference population was defined as lambs born from 2021 to 2023 (n = 792). Two additional populations were defined as the current mature ewe flock (n = 123) and the current mature rams (n = 14). The Genetic Conservation Index averaged 7.7 for the full population and 25.7 for the reference population. Overall inbreeding was 0.003 for the full population and 0.006 for the reference population. The rate of inbreeding was 0.0003 per generation. Average relatedness was 0.015 for the full population and 0.018 for the reference population. The effective number of founders, effective number of ancestors, and founder genome equivalents contributing to the reference population were 60, 39, and 19.1, respectively. The ratio of the effective number of founders to the effective number of ancestors was 1.5, indicating the presence of genetic bottlenecks. Measures of effective population size ranged from 102 to 547. Of the 704 offspring produced by external sires, 17 ram lambs and 132 ewe lambs were retained for breeding. The USSES sires produced 299 offspring with 2 ram lambs and 51 ewe lambs retained. Incorporating external sires resulted in a cumulative percentage of genetic variance of 48.8, 49.1, and 44.2 of external genetics for the reference population, current mature ewe flock, and current mature rams, respectively. Stakeholder needs were addressed by introgression of external sires and participation in NSIP, but future selection practices need to be modified to maintain a minimum of 50% USSES core genetics in the flock.
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  • 文章类型: Case Reports
    OBJECTIVE: The aim of this study was to describe for the first time a natural case of ovine abortion associated with Neospora caninum in a flock with reproductive losses in Argentina.
    METHODS: The analyzed flock consisted of 256 Texel sheep, of which 134 had been mated. A single blood sample was obtained by jugular vein puncture from 220 ewes (116 adult ewes, 104 yearling ewes) and 93 lambs. Serum samples and fetal fluid were tested using the indirect fluorescence antibody test to detect antibodies against N. caninum and T. gondii. Fetal and placental tissues from aborted fetus were examined by standard gross pathology procedures and were tested using histopathology and immunohistochemistry. Moreover, DNA from fetal and placental tissues was isolated and a PCR assay to detect N. caninum, T. gondii and Chlamydia spp. was used.
    CONCLUSIONS: The pregnancy rate was 89% (119/134), the abortion rate was 8.4% (10/119) whereas the perinatal mortality rate was 15% (16/109). Out of 116 adult ewes sampled, 34.48% presented anti-N. caninum antibodies. Ten ewes had aborted, and one fetus was directly submitted to the diagnostic laboratory for further processing. Antibodies against N. caninum were detected in fetal fluid and in the aborted dam. Histopathological analysis in fetal tissues showed multifocal lymphohistiocytic glossitis, diffuse mild lymphohistiocytic endocarditis, pericarditis and focally extensive myocarditis. Severe multifocal necrotizing placentitis and diffuse mild lymphohistiocytic placentitis with the presence of lymphohistiocytic vasculitis were observed in placenta. N. caninum was immunolabeled in the placenta and fetal tongue. In addition, N. caninum DNA was detected in placenta, central neural system, lung and heart of the aborted fetus. There was no evidence of other infectious abortifacients in the aborted fetus.
    CONCLUSIONS: The present study described for the first time an ovine abortion caused by N. caninum in Argentina. Further investigations at a larger scale are required to establish the role of N. caninum as an important cause of reproductive losses in sheep flocks from the region.
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  • 文章类型: Journal Article
    Schmallenberg virus (SBV) was first detected in 2011 in Germany and then in France in 2012. This study simulates the production of different ruminant systems in France and estimates, through partial budget analyses, the economic cost of SBV at the farm level, under two disease scenarios (a high-impact and low-impact scenario). A partial budget is used to evaluate the financial effect of incremental changes, and includes only resources or production that will be changed. In the high-impact scenario, the estimated impact of SBV ranged from €23 to €43 per cow per year and €19 to €37 per ewe per year. In the low-impact scenario, it was approximately half (for cows) or one-third (for ewes) of this amount. These financial impacts represent 0.6% to 63% of the gross margin, depending on the chosen scenario and the livestock system being considered. The impacts of SBV come mainly from: the extra costs from purchasing and raising replacement heifers and losses in milk production (dairy cows); the losses in calf or lamb production (beef systems and meat sheep); and the losses in milk production and from unsold replacement lambs (dairy sheep). The use of integrated production and economic models enabled the authors to estimate the cost of SBV and to tackle the problem of scarce data, which is a difficulty for most emerging diseases, by their very nature. It also allowed the authors to develop an accurate disease impact assessment for several production systems, over a short time span. Extrapolating from this economic assessment to predict the scenario in coming years depends on the immunity period of the disease and the length of the production cycles.
    Le virus de Schmallenberg a été détecté pour la première fois en 2011 en Allemagne, puis en France en 2012. Les auteurs présentent une étude de simulation de plusieurs systèmes de production de ruminants en France, dont l’objectif était d’estimer, à partir d’analyses budgétaires partielles, les coûts économiques du virus de Schmallenberg à l’échelle des exploitations, sous deux scénarios différents (hypothèses d’un fort impact et d’un faible impact de la maladie, respectivement). Une analyse budgétaire partielle sert à évaluer les conséquences financières d’un changement graduel et ne prend en compte que les modifications effectives en termes de ressources et de production. Dans l’hypothèse d’un impact fort de la maladie, l’impact annuel estimé du virus de Schmallenberg variait de 23 à 43 euros par vache et de 19 à 37 euros par brebis. Dans l’hypothèse d’un impact faible, l’impact annuel était deux fois moindre chez les vaches et trois fois moindre chez les brebis que dans la première hypothèse. Ces impacts financiers représentent 0,6 % à 63 % de la marge brute en fonction du scénario choisi et du système de production. Les impacts du virus de Schmallenberg découlent principalement des coûts supplémentaires induits par l’achat et le maintien de génisses de remplacement et d’une baisse de la production de lait (vaches laitières), des pertes de veaux ou d’agneaux (bovins et ovins de boucherie), d’une baisse de la production de lait et du coût des agnelles de remplacement invendues (brebis laitières). L’utilisation de modèles intégrant les aspects économiques et les données de production a permis aux auteurs d’estimer le coût du virus de Schmallenberg malgré la pénurie de données, s’attaquant ainsi à une difficulté inhérente à la plupart des maladies émergentes. Cela leur a également permis d’effectuer une évaluation précise de l’impact sanitaire dans plusieurs systèmes de production, sur une durée courte. La possibilité d’extrapoler à partir de cette évaluation économique un scénario pour les années à venir dépend de la période d’immunité vis-à-vis de la maladie et de la durée des cycles de production.
    El virus de Schmallenberg fue detectado por primera vez en 2011 en Alemania y ulteriormente en 2012 en Francia. Los autores describen un estudio en el que se simularon distintos sistemas de producción de rumiantes en Francia y se estimó, con análisis presupuestarios parciales, el coste económico que entrañaría para una explotación el virus de Schmallenberg en dos hipotéticas situaciones sanitarias (una situación con efectos profundos y otra con efectos leves). El análisis presupuestario parcial sirve para evaluar los efectos económicos de cambios graduales, e incluye únicamente aquellos recursos y aspectos de la producción que experimentarán cambios. En la hipótesis de efectos profundos, el impacto estimado de la infección por el virus de Schmallenberg oscilaba entre 23 y 43 euros anuales por vaca y entre 19 y 37 euros anuales por oveja hembra. La hipótesis de efectos leves deparaba importes de aproximadamente la mitad (en el caso de las vacas) o un tercio (en el de las ovejas). Este impacto económico representa del 0,6% al 63% del margen bruto, dependiendo de la hipótesis elegida y del sistema productivo de que se trate. Los efectos de la infección por el virus de Schmallenberg se concretan básicamente en: los costos suplementarios derivados de adquirir y criar vaquillas de sustitución y de obtener una menor producción de leche (vacas lecheras); las pérdidas de terneros o corderos (sistemas de bovino u ovino cárnicos); y los costos derivados de la menor producción de leche y de no vender las corderas de sustitución (ovejas lecheras). El uso de modelos que integran los factores productivos y económicos sirvió a los autores para estimar el costo del virus de Schmallenberg a pesar de la escasez de datos, que, por la propia naturaleza de las enfermedades emergentes, es una dificultad común a la mayoría de ellas. También les permitió evaluar con exactitud el impacto de la enfermedad en distintos sistemas productivos en un breve lapso de tiempo. La realización de extrapolaciones a partir de esta evaluación económica para pronosticar la situación en años venideros depende del periodo de inmunidad respecto de la enfermedad y de la duración de los ciclos productivos.
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  • 文章类型: Journal Article
    Two-dimensional (2D) gel electrophoresis is a well-proven proteomic technique; however, sample-specific optimisation can often be necessary in order to get consistent quantitation. In particular, plasma samples are often smeared on 2D gels making spot matching difficult. A variety of different sample preparation and 2D methods were tested by using sheep plasma, and it was found that lowering sample pH prior to precipitation, using a long voltage gradient for isoelectric focusing and the inclusion of carrier ampholytes in the electrode wicks, improved both the quality and consistency of spot resolution. Analysis of the internal standards from two different DIGE experiments, one with conventional methodology and one with the improved method, showed that along with substantially improving the number of spots resolved, the average CV (coefficient of variation) of matched standards was lower with the new method. 428 matched spots were found using the improved method compared to 208 matched spots using conventional methodology. For the 174 spots that were matched between the two DIGE experiments, the average CV\'s of spot volumes were also significantly lower, at 0.20 for the new method compared to 0.24 for the conventional method (p < 0.001).
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    文章类型: Case Reports
    Paratuberculosis (Johne\'s disease) was suspected in a herd of approximately 300 sheep after weight loss and scouring had increased in adult animals despite repeated treatment with anthelmintics, antibiotics, multivitamins and minerals. The herd is located near Tarhouna city. Herd history revealed that a total of 60 ewes showed clinical symptoms and deaths during the last two years. The last case that we attended was submitted to the National Center of Animal Health (NCAH) for a detailed laboratory examination. Gross pathological and histological examination of tissue samples revealed results that were highly comparable with Johne\'s disease. A definitive diagnosis was made only by histopathological identification of Mycobacterium paratuberculosis in the intestines using Ziehl-Neelsen stain. This is the first documented case of M. paratuberculosis in sheep in Libya.
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