924 resultados para Dairy cattle Breeding Australia Statistics Data processing
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Intoxicação crônica por cobre foi observada em um rebanho de 20 ovinos no município de Franca, São Paulo. Três meses após o início do arraçoamento com feno e ração concentrada peletizada para bovinos de leite, seis animais apresentaram anorexia, icterícia severa e urina marrom escura, e vieram a óbito. Diagnosticou-se doença hemolítica com base em sinais clínicos, alterações macroscópicas observadas na necropsia e observações histológicas. À necropsia todos os ovinos apresentaram icterícia severa, fígado amarelado com padrão lobular evidente e rins escuros. As principais alterações histológicas incluíram necrose hepática periacinar e nefrose hemoglobinúrica. Acúmulos de cobre foram demonstrados nos hepatócitos e macrófagos pela coloração rodamina e níveis elevados de cobre mediante espectrofotometria de absorção atômica no soro, fígado e rins de dois ovinos afetados e na ração fornecida.
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Genetic gains predicted for selection, based on both individual performance and progeny testing, were compared to provide information to be used in implementation of progeny testing for a Nelore cattle breeding program. The prediction of genetic gain based on progeny testing was obtained from a formula, derived from methodology of Young and weller (J. Genetics 57: 329-338, 1960) for two-stage selection, which allows prediction of genetic gain per generation when the individuals under test have been pre-selected on the basis of their own performance. The application of this formula also allowed determination of the number of progeny per tested bull needed to maximize genetic gain, when the total number of tested progeny is limited.
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Sera collected from 447 dairy cattle on 14 dairy farms were tested for Neospora caninum antibodies by use of an immunofluorescent antibody technique. Positive reactions with titres greater than or equal to 1:200 were found in 63 (14.09%) of animals. Neospora positive sera were also tested for Toxoplasma gondii antibodies by using a commercial latex agglutination test. Antibodies to T. gondii were detected in 3 (4.76%) of 63 N. caninum positive sera. These results indicate that N. caninum infection is widespread among dairy cattle in Bahia state. (C) 1999 Elsevier B.V. B.V. All rights reserved.
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Genetic gains predicted for selection, based on both individual performance and progeny testing, were compared to provide information to be used in implementation of progeny testing for a Nelore cattle breeding program. The prediction of genetic gain based on progeny testing was obtained from a formula, derived from methodology of Young and Weiler (J. Genetics 57: 329-338, 1960) for two-stage selection, which allows prediction of genetic gain per generation when the individuals under test have been pre-selected on the basis of their own performance. The application of this formula also allowed determination of the number of progeny per tested bull needed to maximize genetic gain, when the total number of tested progeny is limited.
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Globalization of dairy cattle breeding has created a need for international sire proofs. Some early methods for converting proofs from one population to another are based on simple linear regression. An alternative robust regression method based on the t-distribution is presented, and maximum likelihood and Bayesian techniques for analysis are described, including the situation in which some proofs are missing. Procedures were used to investigate the relationship between Holstein sire proofs obtained by two Uruguayan genetic evaluation programs. The results suggest that conversion equations developed from data including only sires having proofs in both populations can lead to distorted results, relative to estimates obtained using techniques for incomplete data. There was evidence of non-normality of regression residuals, which constitutes an additional source of bias. A robust estimator may not solve all problems, but can provide simple conversion equations that are less sensitive to outlying proofs and to departures from assumptions.
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The CMS Collaboration conducted a month-long data taking exercise, the Cosmic Run At Four Tesla, during October-November 2008, with the goal of commissioning the experiment for extended operation. With all installed detector systems participating, CMS recorded 270 million cosmic ray events with the solenoid at a magnetic field strength of 3.8 T. This paper describes the data flow from the detector through the various online and offline computing systems, as well as the workflows used for recording the data, for aligning and calibrating the detector, and for analysis of the data. © 2010 IOP Publishing Ltd and SISSA.
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The objective of this study was to report the presence of Neospora caninum-associated abortion in bovines at a farm in the northeast region of São Paulo State. In January 2010, it was sent to the Department of Pathology, UNESP-Jaboticabal, a bovine fetus with an estimated age of seven months, which was natural of a dairy farm with 300 animals and an average daily production of 3,000 liters of milk, nearly 20 liters per cow. The animals were vaccinated against rabies, foot and mouth disease, carbuncle, brucellosis, leptospirosis, bovine herpes virus type I and bovine viral diarrhea virus. The herd consisted of purebred Holstein animals, Jersey, and mostly by crossbred animals 7-8 (gir x holstein). During necropsy, samples of the serosanguineous liquid present at the thoracic cavity and the heart of the fetus were collected for the detection of anti-Neospora caninum antibodies through Indirect Immunofluorescence Assay (IFA). Fragments of brain, cerebellum, tongue, liver, heart and kidneys were collected for the execution of histopathology (HP), immunohistochemistry (IHC) and Polymerase Chain Reaction. In order that IFA could be performed, the owner was requested blood samples without anticoagulants of the mother and other cows in the farm, with or without a history of abortion. At necropsy, it was verified a severe autolysis of the fetus. The serology of the fetus was 1:25, while the serology of the mother was 1:3,200. At HP, it was observed discrete multifocal non-suppurative encephalomyelitis characterized by gliosis and mononuclear inflammatory infiltration associated with cellular debris. DNA amplification of N. caninum was positive in fragments of brain, tongue, cerebellum, heart and kidneys. At IHC, it has been observed immunoreactivity to a cyst located in the tongue. The owner reported that his herd showed endemic episodes of abortion, while 27.69% (18/65) of the 65 animals sampled were seropositive. Although it has not been a significant difference (p>0.05), a higher seropositivity was observed in animals with a history of abortion (10/26) 38.46%, in comparison with animals without previous abortion (8/39) 20.51%. These findings show that the abortion under study was provoked by the protozoan N. caninum, while this is the first report concerning cattle in the northeast region of São Paulo State.
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Nowadays, L1 SBAS signals can be used in a combined GPS+SBAS data processing. However, such situation restricts the studies over short baselines. Besides of increasing the satellite availability, SBAS satellites orbit configuration is different from that of GPS. In order to analyze how these characteristics can impact GPS positioning in the southeast area of Brazil, experiments involving GPS-only and combined GPS+SBAS data were performed. Solutions using single point and relative positioning were computed to show the impact over satellite geometry, positioning accuracy and short baseline ambiguity resolution. Results showed that the inclusion of SBAS satellites can improve the accuracy of positioning. Nevertheless, the bad quality of the data broadcasted by these satellites limits their usage. © Springer-Verlag Berlin Heidelberg 2012.
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Anaplasma marginale is the most prevalent pathogen of cattle transmitted by ticks in the world. This study aimed to evaluate the risk factors for anaplasmosis in dairy cattle. Fifty dairy cattle from the herd of Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro were selected by proportional stratified sampling. The risk factors evaluated were: physiological state, race pattern, number of lactations, milk production, infestation by Rhipicephalus microplus and animal density. Antibody activity against A. marginale was determined using the indirect enzyme-linked immunosorbent assay. The percentual values of seroprevalence for A. marginale were submitted to X2 test, and the level of minimum significance, to keep a factor in the model of logistic regression, was fixated in 5%. It was observed that pregnancy and lactation influenced significantly (p<0.05) in the seropositivity of the animals. Bos indicus animals had 5.21 times more chances of being seropositive than B. taurus animals. Primiparous female had 88% more chances of being seropositive than pluriparous female. Animals with high milk production were 63% more positive than low production animals. When infested by ticks the animals had 39% more chance of being seropositive to A. marginale. Bos indicus animals presented 5.21 times more chance of being seropositive than B. taurus animals. Primiparous females presented 88% more chance of being seropositive than the pluriparous ones. High milk production animals were 63% more positive than the low production ones. When infested by ticks the animals had 39% more chance of being seropositive to A. marginale. High density grazing provided for the animals 3.2 times more chances of being seropositive than low density ones. The herd was classified as erratic to A. marginale, even being placed in a steady enzootic area.
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We analyzed 46,161 monthly test-day records of milk production from 7453 first lactations of crossbred dairy Gyr (Bos indicus) x Holstein cows. The following seven models were compared: standard multivariate model (M10), three reduced rank models fitting the first 2, 3, or 4 genetic principal components, and three models considering a 2-, 3-, or 4-factor structure for the genetic covariance matrix. Full rank residual covariance matrices were considered for all models. The model fitting the first two principal components (PC2) was the best according to the model selection criteria. Similar phenotypic, genetic, and residual variances were obtained with models M10 and PC2. The heritability estimates ranged from 0.14 to 0.21 and from 0.13 to 0.21 for models M10 and PC2, respectively. The genetic correlations obtained with model PC2 were slightly higher than those estimated with model M10. PC2 markedly reduced the number of parameters estimated and the time spent to reach convergence. We concluded that two principal components are sufficient to model the structure of genetic covariances between test-day milk yields. © FUNPEC-RP.
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Includes bibliography
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El Sub-Programa de Documentacion en Poblacion y Procesamiento de Datos del CELADE se compone de tres elementos que corresponden a los primeros objetivos inmediatos del mismo: el Sistema de Documentacion en Poblacion para America Latina (DOCPAL), el Banco de Datos y la Unidad de Procesamiento de Informacion. El presente documento describe los objetivos, antecedentes y justificacion de cada uno de estos tres nucleos, asi como las actividades contempladas para el periodo 1980-1983 y que fundamentan el presupuesto contenido en la solicitud de fondos al UNFPA