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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Avaliação de método enzimático para monitorar a presença de agrotóxicos organofosforados em leite bovino / Evaluation of enzimatic method to monitorate the presence of organophosphates pesticides in cow milk

Morais, Christina Maria Queiroz de Jesus January 2009 (has links)
Made available in DSpace on 2014-08-26T17:15:07Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 85.pdf: 911776 bytes, checksum: 157643f210a8dc4b9b4da249344c2332 (MD5) Previous issue date: 2009 / Os testes de triagem por serem sensíveis, específicos, rápidos e de baixo custo, vêmsendo largamente utilizados no monitoramento de contaminantes químicos, como osagrotóxicos, visando à prevenção de riscos para a saúde humana. Estes tipos de testes têmsido aplicados no monitoramento de um grande número de amostras, permitindo que aanálise cromatográfica seja realizada apenas em amostras potencialmente não-conformes, oque reduz substancialmente o custo. O leite bovino é um alimento essencial na dieta do serhumano e, especialmente, de crianças e são poucos os trabalhos de monitoramento deresíduos de agrotóxicos, neste tipo de alimento, realizados no Brasil. O aparecimento deresíduos de agrotóxicos no leite pode ocorrer pelo uso de rações e pastagens contaminadas,ou pelo tratamento, com agrotóxicos, especialmente alguns organofosforados, contraectoparasitas que atacam os animais. Desenvolveu-se um método de extração de resíduos de agrotóxicosorganofosforados (OFs) em leite bovino para detecção qualitativa desta classe desubstâncias através da inibição da atividade da enzima acetilcolinesterase (AChE) eposterior confirmação pela cromatografia gasosa (CG). Através das pesquisas realizadas estabeleceu-se um protocolo de extração dosagrotóxicos OFs de amostras de leite bovino para posterior detecção utilizando o kitenzimático e confirmação pela cromatografia em fase gasosa, bem como as condiçõesideais de análise usando o kit desenvolvido pelo Laboratório de Toxicologia Enzimática(ENZITOX) da Universidade do Estado do Rio de Janeiro (UERJ), próprio para análise deOFs em água, adaptado para a detecção de organofosforados em leite bovino. O leite foicontaminado com parationa metílica e clorpirifós etil de modo que a concentração dessassubstâncias variassem na faixa de 5 a 200 ng/ml. Os resultados obtidos demonstraram que os métodos de extração e de detecção porinibição enzimática propostos, para o leite integral, permitem detectar, com segurança,níveis tão baixos quanto 5 ng/ml de clorpirifós, menor que o LMR não intencionalestabelecido pela ANVISA/MS que é de 10 ng/ml de clorpirifós etil na gordura do leite.Desde que somente concentrações de clorpirifós a partir da de 10 ng/ml foram detectadaspor cromatografia gasosa, nosso método mostrou-se mais sensível. O kit de inibiçãoenzimática demonstrou ser apropriado para monitoramento de contaminação do leite porclorpirifós. / Rapid and practical methods, like screening assays having sensibility, specificity, and low cost are widely used in monitoring programs for risk prevention of chemical contaminants. Screening tests are used as strategic tools when a large number of samples are involved. In these cases, chromatographic analysis is carried out only in potentially non-conforming samples, substantially reducing monitoring costs. The bovine milk is an essential food in adult and, specially, children diets. Considering that caws can accumulate such residues in milk from ingested food and also during ectoparasite treatment with insecticides and taking into account that, so far, a few pesticide monitoring programs in bovine milk were carried out in Brazil, we now propose, for this purpose, a practical methodology which could be useful in large scale survey programs. A method of extraction of organophosphorus pesticides in bovine milk was developed for the qualitative and quantitative detection of these substances. This technique is based on the inhibition of the acetylcholinesterase (AChE) enzyme by organophosphates that can be subsequently confirmed by gas chromatography. The enzymatic screening method used in this work, was initially developed by the ENZITOX laboratory of the Universidade do Estado do Rio de Janeiro (UERJ), for the detection organophosphate and carbamate pesticides in the water. Therefore, the main objective of this work was to establish an organophosphate extraction protocol which could efficiently perform on the fat enriched-bovine milk matrix and, thus, be used in the simultaneous detection by enzymatic and chromatographic methods. For this purpose, milk samples were fortified with methyl-parathion and chlorpyriphos-ethyl in the concentration range 5 - 200 ng/ml. Results demonstrated that the proposed milk extraction and enzyme detection methods were able to efficiently detect 5 ng/ml of chlorpyriphos. The gas chromatographic method used could only detect chlorpyriphos from the initial concentration of 10 ng/ml. The ANVISA establishes a not intentional LMR of 10 ng/ml for chlorpyriphos-ethyl in milk samples. The proposed methodology proved to be appropriated and efficient for use in wide scale milk monitoring programs evaluating the presence of organophosphate pesticides.
192

Parâmetros físicos de bovinos leiteiros submetidos ao estresse térmico / Physical parameters of dairy cattle subjected to heat stress

Alfonzo, Evelyn Priscila München January 2014 (has links)
O objetivo deste trabalho foi determinar as características físicas preditoras do efeito do calor sobre os diferentes grupos genéticos de bovinos leiteiros. Foram utilizados trinta e oito animais, entre eles 19 da raça Holandesa, 08 Girolando ½ Holandês e 11 Girolando ¾ Holandês. Foram realizadas mensurações para as características físicas, como: espessura da pele e pelame, contagem e comprimento de pelos e medidas corporais, sendo essa realizada uma única vez por animal. Os parâmetros fisiológicos coletados foram: temperatura retal (TR), frequência respiratória (FR), frequência cardíaca (FC), escore de ofegação (EO). As imagens termográficas foram obtidas por uma câmera infravermelha (FLIR® System T300), onde se coletaram as temperaturas das regiões do lado direito (Ladod), lado esquerdo (Ladoe), olho direito (Olho), visão lateral do úbere direito (Uberelat), visão posterior do úbere (Uberetras) e pata dianteira direita na visão posterior (Pata). Os bovinos da raça Holandesa foram mais sensíveis ao estresse térmico por calor em relação aos Girolando (1/2 e 3/4 Holandês). A análise discriminante identificou o perímetro torácico como a característica física que tem influência na tolerância ao calor dos animais. A análise canônica separou os animais da raça Holandesa dos animais da raça Girolando ½ e ¾ Hoandês. A porcentagem de variação nos fatores principais foram maiores durante a tarde do que na manhã, porém foram baixos. As regressões e correlações não foram significativas, assim as características físicas não foram boas em predizer os indices fisiológicos e as temperaturas termográficas, portanto não devem ser utilizadas. / The objective of this study was to determine the physical characteristics predictive of the effect of heat on different genetic groups of dairy cattle. Thirty eight animals, including 19 Holstein, 08 Gir ½ Holstein and 11 Gir ¾ Holstein were used. Measurements to the physical characteristics were carried out: skin and coat thickness, number and length of hair and body measurements, performed once per animal. The physiological parameters collected included: rectal temperature (RT), respiratory rate (RR), heart rate (HR) and panting score (SP). Thermographic images were obtained by an infrared camera (FLIR T300 ® System), which collected the temperatures of the regions on the right and left side, eye, lateral view of the right udder, posterior view of the udder and right front leg in posterior. The Holstein cattle were less tolerant to heat stress than Girolando (1/2 and 3/4 Holstein) because these animals had difficulties in dissipating heat due to the larger body size, as well as thicker and longer coats. The correlations between physical characteristics, physiological parameters and thermographic measures were inconsistent between genetic groups are therefore not predictive of heat tolerance, while the regressions of morphometric characteristics on physiological and thermographic were not significant. Thus physical characteristics were not good at predicting the physiological indices or thermographic temperatures and therefore should not be used as measures of heat tolerance in dairy cattle.
193

Kvalita objemných krmiv ve vztahu k ekonomice výroby mléka / Quality roughage feed in relation to the economy of milk production

NÁVARA, Drahoslav January 2012 (has links)
The aim of this thesis was to evaluate in selected levels of nutrition and feeding of dairy cows in relation to the economy of milk production and suggest possible options for improving the profitability of milk production. They have been selected four firms, two keeping Holstein cattle and two with red coloured cattle. One company was with highest production and the second company was with average production. The aim was to assess the profitability of milk production at peak and average enterprises, especially given the quality of forage and the cost of ration. The selected companies we evaluated the composition of feed rations, especially forage quality indicators. For assessment of milk production of dairy cows were selected for the second group, or third lactation calved in the same period, and after ten pieces from each company. We also evaluated the cost of feeding dairy cows in milk and in particular the cost to produce one liter of milk a day and feed at the cost of production for the entire lactation. Selected breeds we all observed points compared with each other.
194

Analýza vybraných vlivů na reprodukci dojnic u stáda holštýnského skotu / The Analysis of Selected Impacts on Reproduction of Dairy Cows in a Herd of Holstein Cattle

PROVAZNÍK, Pavel January 2013 (has links)
The diploma thesis deals with the analysis of selected effects on reproduction of Holstein dairy cows. Breeding of cattle faces up to so impaired indicators of reproduction that it could cause the decrease of economic efficiency in production of milk and meat. The aim of the thesis is the evaluation of selected effects that influence the reproduction of dairy cows in the farm in Trhový Štěpánov. Information about reproduction were gained from records of efficiency controls and animal husbandry records of the year 2012. The observation included total 515 Holstein dairy cows (H100) and 1 784 inseminations were carried out. From this amount 350 dairy cows were gravid. Gained data were selected by sequence of lactation, level of dairy efficiency, inseminating bulls and synchronizing programmes. Established results showed that the only reliable indicator was the interval of insemination. Average length of interval of insemination amounted to 79,9 days. The other figures of reproduction indicators were found out below-average comparing the avarage figures of Holstein cattle. Average service period of studied dairy cows was 197,1 days and the length of between-period was 477,1 days. It was found out very low average percentage of gravidity after the first insemination (12,6 %). Average number of doses of insemination for one gravid cow was 3,5. The biggest effect on reproduction indicators had the level of dairy efficiency (P < 0,05). The shortest service period and between-period had dairy cows with efficiency of 7 000 to 10 000 kg of milk. It was not proved the influence of RPH of breeding bulls for gravidity of breeding-cows. The highest percentage of gravidity after all inseminations was after application of EOSTROPHAN (30,5 %). The worst synchronizing programme was DOUBLE OVSYNCH (12 %). The percentage of gravidity after all inseminations and synchronizing programmes was 20,4 % and after spontaneous rut only 15 %.
195

Sezónní změny metabolického profilu dojených krav / Seasonal changes in the metabolic profile of dairy cows

KADLECOVÁ, Lenka January 2014 (has links)
V teoretické části mé diplomové práce bylo cílem zpracovat přehled literatury, která se zabývá chovem, výživou a zdravotními problémy dojených plemen skotu v České republice a významem preventivních metabolických vyšetření. Dále pak popsat postup provádění a hodnocení metabolických profilových testů u dojnic. Praktická část byla zaměřena na zhodnocení vybraných ukazatelů metabolického profilu u dojnic plemene holštýn a český strakatý skot na rodinné farmě Velký Bor, kdy dojnice plemene holštýn dosahovaly užitkovosti 7450 litrů mléka za laktaci a dojnice český strakatý skot 6725 litrů mléka za laktaci. Vyhodnocování probíhalo v metabolicky nejnáročnější fázi laktace, tedy v období po porodu a ve vzestupné fázi laktace. Výsledky ukazují, že při uvedené užitkovosti dojnic plemene holštýn, která byla o 725 litrů vyšší než u dojnic plemene český strakatý skot, mezi metabolická rizika patří nedostatek Ca, Na a energetický deficit. To může vést k vyšší pravděpodobnosti vzniku metabolických onemocnění, především v období po porodu, oproti dojnicím český strakatý skot, které byly z hlediska užitkovosti méně zatíženy. Z hlediska ročního období a rozdílné krmné dávky v zimním a letním období dojnic nebyly výrazné rozdíly v hlavních sledovaných parametrech v krevním séru a moči, které by poukazovaly na vyšší riziko vzniku metabolických onemocnění. Avšak hodnoty bližší zvoleným normám vykazovaly profily v zimním období.
196

Aktivita štítné žlázy skotu / Activity of the thyroid gland of cattle

KŘÍŽOVÁ, Zuzana January 2014 (has links)
The thesis deals with the evaluation of the impact of different quantities and forms of iodine in ration dairy cows on the concentration of hormones of the thyroid in the blood plasma. The experiment was done with a herd of Red cows breeding in the conversion to breed in the breeding of Holstein dairy cows in Klatovy. Iodine was given in both inorganic and organic form. Before experimenting, the value of total and free forms of hormones was very low. During the experiment, increased concentrations of hormones in connection with the intake of inorganic iodine, the significant deviations showed free forms of thyroid hoemones. Nevertheless, the addition of organic iodine was not fully substituted for the reduction of inorganic iodine content. The thesis also discusses the assessment of the thyroid status by Czech red cattlebreeding on the school farm. The aim was to compare the activity of the thyroid gland in high-yield dairy cows breeding in a barn environment and cattle on pasture reared cattle. For red cattle reared on pasture, there were characteristically higher concentration levels of total and free hormones compared with high yield dairy cows. Nevertheless, in comparison with the reference value,there was a concentration of TT4 for Czech red cattlelower, it coresponded well as dairy cows, rather lower iodine supply. In connection with the rise (higher content) TT4, possibly fT4, there was a similar tendency for the TT3 and fT3, so we can´t assume a deeper state of iodine deficiencies and its associationwith an underactive thyroid gland.
197

Porovnání vlivu dojení krav dojicím automatem a rybinovou dojírnou na vybrané parametry welfare dojnic / Comparison of influence milking cows milking machine and herringbone milking parlors on selected parameters welfare of dairy cows

PROVAZNÍKOVÁ, Iveta January 2014 (has links)
The aim of this diploma thesis was to obtain basic information about the milking process and than formulate findings about the behavior of dairy cows during milking and after 30 minutes after milking. There were compared data obtained during the milking in the milking parlor with a robot and in conventional milking parlor. Ethological observation was conducted for 24 hours and was focused on all milked cows during three different seasons at two different farms. During the monitoring there were conducted observations on 862 pieces 478 pieces on the farm with a milking robot and 384 pieces on the farm with a herringbone milking parlor. The data collection took place during the observation of the Holstein cattle and was focused in three areas of animal behavior. There was compared the need for feed intake, drinking and lying down of cows 30 minutes after they leaved the milking equipment. Obtained results were evaluated by means of two programs Microsoft Excel and Statistics 9.
198

Kulhání-Limitující faktor reprodukce skotu

VRABČEKOVÁ, Monika January 2018 (has links)
One of the basic conditions for achieving a positive production and meeting economic objectives in cattle breeding is their high and regular reproductive performance. Amongst the most significant factors influencing cattle fertility is the health state of heifers. To breed cattle successfully, it is essential to ensure that their feet are in a good condition, in particular hoofs. Diseased feet lead to the reduction of cattle performance and affect their welfare which results in a negative impact on cattle fertility. This thesis is concerned with the influence of cattle lameness on reproductive indicators of cows. For the purpose of the research, a group of cows from ZD Pluhuv Zdar including 843 dairy cows of the Holstein breed and Czech Simmental breed was studied. Equally, all cows originated from two different types of stabling. The following information were checked about each cow: the identification number, stabling number, breed, age, date of calving, order of lactation, performance, interim period, service period, insemination interval, insemination index and any relevant hoof problems. The impact of hoof problems on reproductive indicators that depended on the order of lactation and breed were analysed in the program Statistica using two-factor anova. It was observed that there existed a significant influence of hoof disease on each reproduction indicator. Dairy cows on the 3rd and higher level of lactation showed an evident difference in the length of the interim period. It was found that healthy dairy cows without any hoof disease had on average 385 day long interim period, whereas dairy cows with hoof problems had 398 day long interim period. It is apparent that the interim period was lengthened by 13 days in dairy cows with lameness. In addition, the values for service period and insemination index increased in the group with cattle lameness (by 17 days and the value of 3.17). In the case of insemination interval values, the difference between healthy and diseased cows was the least apparent. Furthermore, it was proven that the combination of infectious and non-infectious diseases have the greatest impact on reproduction indicators that seem to increase their value as a result. This causes a great deal of stress to an organism of an animal. When comparing reproduction indicators between breeds, it was noticeable that there was an influence on the cross breeding and how strained the Holstein breed was. The average length of interim period was 8 days longer in the Holstein breed group than Czech Simmental cattle. Furthermore, the length of the service period was 5 days longer in the Holstein cattle group. From the data, it can be concluded that any hoof disease in herds should not be neglected and stock breeders should pay increased attention to hoof problems since it could pose a risk on the whole stock breeding economics. A stock breeder should focus on the regular and careful trimming, washing and treatment of hoofs. In addition, attention should be paid to stabling and how comfortable it is for dairy cows, as well as the quality and complexity of feeding portions that are served.
199

Faktory ovlivňující výskyt mastitid ve vybraném chovu a návrh jejich řešení

TLUSTÁ, Tereza January 2018 (has links)
A mastitis is an inflammatory illness of a milk gland, currently the mastitis is one of the most common health problems in cattle breeding. In most cases the mastitis is caused by bacterial infections of an udder, it can be also caused by viruses, protozoa, yeast, algae and molds. There are huge variety of factors reducing defensive immune mechanisms of the udder and predispose a cow for the inflammation. An etiology of mastitis and mainly ways of prevention are very interesting not only for dairy cows breeders, but also for researchers, scientists and veterinarians. Main reason is economy of dairy cattle the inflammation of milk gland reduces actual milk production, it can influenced milk yield in next lactations and lenght of productive life of the dairy cow too. Usually culling rate and death rate grow. The mastitis has negative effect on reproduction and health status of the cow, especially on hooves' health; that also leads to shortening of cow's productive life and necessity of faster replacement of affected cows by heifers. An aim of this work is to found out risk factors which enlarges chance of the mastitis. Rate of mastitis is influenced by an age of a cow and a number of lactation, a number of days in lactation, an age of a cow at the 1st calving, an yield of the previous lactation, cases of mastitis at the 1st and next lactations and health problems on start of a lactation. A number of treated teats is influenced by an age of a cow at the 1st calving, an yield of the previous lactation and days of the dry-period. Negative effect of mastitis on the reproduction wasn't completely demonstrated; there were only found out that higher number of treating cases extends time between calvings.
200

Associação de escores de condição corporal com características reprodutivas de vacas Nelore e com desempenho de seus bezerros

Fernandes, Anna Flávia de Araujo [UNESP] 28 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T18:29:27Z : No. of bitstreams: 1 fernandes_afa_me_jabo.pdf: 322816 bytes, checksum: d60d045e58509fb91c9a8dc47345094d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No Brasil, são escassos os estudos referentes ao escore de condição corporal (ECC) de vacas de corte que, quando associado ao peso, têm impacto na produção de bezerros e na reprodução, pois reflete o balanço energético do corpo animal. Assim, o objetivo deste trabalho foi associar ECC com a prenhez de vacas Nelore e com o desempenho de seus produtos a desmama, bem como verificar se esta característica pode ser incluída nos critérios de seleção da raça Nelore. O ECC das vacas foi atribuído no diagnóstico de gestação ou no desmame, variando de 1 a 5. Por regressão logística, utilizando o método de seleção Stepwise, foram analisados os seguintes efeitos sobre o ECC: grupo de contemporâneos a desmama, peso e altura de garupa da vaca, ordem de parto, diagnóstico de gestação, histórico reprodutivo anterior à coleta do ECC, presença de bezerro ao pé e escores de C e P dos produtos a desmama. Na análise genética, elaborada usando-se inferência baeysiana, foram incluídos os mesmos efeitos anteriores, com peso e altura de garupa da vaca como co-variáveis, e acrescidos do efeito genético aditivo da vaca. Os resultados mostraram que vacas com ECC elevado emprenharam mais do que as de pior ECC, porém o desempenho dos seus bezerros foi inferior. Vacas multíparas foram mais pesadas e de escores mais magros (ECC 1 e 2). As correlações de Spearman entre ECC e suas fontes de variação foram, em sua maioria, de baixa magnitude. Os efeitos que mais explicaram a variação do ECC foram peso, grupo de contemporâneos e altura da garupa. A estimativa de herdabilidade do ECC foi igual a 0,22, com intervalo de credibilidade entre 0,13 e 0,31, valor de magnitude moderada, demonstrando a presença de ação gênica aditiva na determinação do ECC e que este pode ser utilizado como critério de seleção de vacas / In Brazil few studies have been done on the body condition score (BCS) of beef cows. The knowledge of this score associated with body weight can produce an impact on calf production and cow´s reproduction, because it reflects the energy balance of the animal body. The objective of this study was to associate BSC with pregnancy of cows and the performance of their calves at weaning, and to verify if this trait could be included as selection criteria. The BCS was recorded on pregnancy diagnosis or at weaning and ranged from 1 to 5. Applying logistic regression, using the Stepwise selection method, we analyzed the following effects on BSC: contemporary group at weaning, classes of weight and hip height of the cow, number of calvings, pregnancy diagnosis, reproductive history prior to collection BSC, the presence of calf and C and P score of calves at weaning. For the genetic analysis, performed using Baesyan inference, the same effects were considered, with weight and hip height as covariate, and also the genetic direct effect of the cow. The results showed that cows with higher BCS had better pregnancy rate than those with lower BSC, but the performance of their calves was worse. Multiparous cows were heavier and had leaner scores (BCS 1 and 2) than the primiparous ones. The Spearman rank correlation between BSC and their sources of variation were generally of low magnitude. Contemporary group, body weight and height of the cow were the effects that accounted for most of the variation of BSC. The heritability estimate of BCS was equal to 0.22 with credible interval ranging from 0.13 to 0.31, a moderate magnitude value that indicates the presence of additive genetic variation and that BSC can be used as selection criterion for cows

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